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Farming system
Farming system is a complex of agrotechnical, reclamation, organizational and economic measures aimed at rational and efficient use of land and other resources, reproduction of soil fertility in order to obtain maximum and sustainable yields of crops.
Used land means arable land, as well as land which may be used for agricultural purposes: meadow and pasture land, swamped land and land overgrown with tree and shrub vegetation, disturbed land which is subject to recultivation.
Modern agriculture is a complex multi-component system, the individual components of which are in relationship with each other and the natural environment.
Farming system (Русский Español)
- Development of the teaching of farming systems in Russia
- Types of farming systems
- Farming in the Non-Black Earth zone
- Farming in the Central Black Earth zone
- Farming in the Volga Region
- Farming in the North Caucasus
- Farming in the steppe and forest-steppe regions of Siberia
- Farming in the Far East (Russia)
- Farming of irrigated regions
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Farming system (Русский Español)
- Development of the teaching of farming systems in Russia
- Types of farming systems
- Farming in the Non-Black Earth zone
- Farming in the Central Black Earth zone
- Farming in the Volga Region
- Farming in the North Caucasus
- Farming in the steppe and forest-steppe regions of Siberia
- Farming in the Far East (Russia)
- Farming of irrigated regions
Development of the teaching of farming systems in Russia
Main article: Farming systems: The development of the teaching of farming systems in Russia
The teaching of farming systems in Russia emerged in the second half of the 18th century thanks to the works of agricultural scientists A.T. Bolotov, I.M. Komov, V.A. Levshin and agricultural practitioners of the early 19th century – D.M. Poltoratsky, I.I. Samarin.
During the period of feudal reform of land ownership, serfdom of peasants and communal land tenure the fallow system of agriculture with the usual three-field cereal crop rotation was widespread.
The teaching was developed in XIX century in the works of M.G. Pavlov, A.V. Sovetov, A.N. Engelhardt, A.P. Ludogovsky, I.A. Stebut, etc.
In the Soviet period, a great contribution to the science of agriculture was made by D.N. Pryanishnikov, V.R. Williams and other Soviet scientists.
Farming systems are divided into:
- primitive:
- slash-and-burn;
- forest-grassland;
- fallow;
- swidden;
- extensive:
- fallow;
- multi-field grassland;
- transitional:
- improved cereal;
- grass-field;
- intensive:
- cereal-grass-row;
- industrial-plant (row crop);
- zonal;
- alternative.
Agrolandscape farming
Agrolandscape, or adaptive-landscape, farming is a farming system adapted to local landscapes that meets the requirements of environmental safety, rational land use and soil fertility reproduction, obtaining high and sustainable yields.
Agrolandscape system of farming exists only at the level of agricultural enterprise (farm). General distinctive features of landscape systems of enterprises in the region can be formulated for the district, region.
Landscape is a relatively homogeneous section of the geographical shell of the land, isolated in the course of its evolution and distinguished by its structure, the nature of the relationship and interaction between components. Landscapes that have been developed by agricultural production are called agrolandscape. In the process of agricultural use, the natural landscape is not changed to its core, but only partially transformed.
Agrolandscape is a natural and productive territorial complex of agricultural purposes, functioning as a natural and anthropogenic resource-reproducing and environment-forming geo-ecosystem.
Until recently, in the development of farming systems the main task was to achieve a given value of crop yields by meeting the biological needs of crops. Modern farming systems, in addition to achieving the goal of maximum production, are required to make the best possible balanced use of the resource potential without harming the environment. In order to realize this goal, agrolandscape farming should represent an agrolandscape management system based on the laws of natural systems functioning.
The development of agrolandscape farming systems is based on the following principles:
- zonality,
- adaptability of crops,
- adaptation of cultivation technologies to terrain conditions,
- integrity of the functioning of elements and parts of the system as a whole,
- optimization,
- normativity, i.e. dosage of intensification factors,
- environmental orientation,
- socio-economic expediency,
- environmental safety,
- aesthetic attractiveness.
In practice, this is achieved by rational transformation of land, the selection of crops and improving the structure of cultivated areas adapted to local soil and climatic and hydrogeological conditions, placement of agricultural crops, taking into account mutual influences in agricultural systems, the rational use of natural forage lands, the optimal allocation of agricultural land for other types, such as forest plantations, hydrotechnical structures.
When developing agrolandscape farming systems, priority should be given to the landscape morpho-genetic structure of the territory over administrative and economic boundaries. The establishment of agro-landscape boundaries should be carried out after the environmental organization of the agrolandscape. Therefore, the development of agrolandscape systems requires:
- classification, mapping and typification of agrolandscapes;
- analysis of the potential of natural and anthropogenic resources;
- scheme of the intensity of material and energy flows, taking into account the
- conjugation of cascade landscape-geochemical systems;
- monitoring;
- method of ecological and economic evaluation of agrolandscape systems.
Since the agrolandscape farming system is developed for a specific territory, in the process of its design it is necessary to use unified taxonomic units of the agrolandscape that meet the requirements of:
- clarity of allocated boundaries;
- unified functioning of the system of agrolandscape elements;
- ensuring assessment and control of the functioning regime.
These requirements are well met by elementary watersheds (gully, valley, ravine, etc.), within the boundaries of which the resource potential is evaluated and the ways of rational land use of the territory are determined.
The methodological basis for designing agrolandscape farming systems is the systematic approach and modeling. Given that the development of a farming system for a particular taxonomic unit of agrolandscape is a complex process, the basic model of the system should be considered from the position of the structure model and the model of functional properties. The basic model includes models of individual elements of the farming system, models of regimes and processes occurring in agrolandscapes, as well as models of relationships, uniting private models into one whole.
The essence of modern farming systems
The essence of the farming system as a scientifically grounded agro-ecological-economic complex is determined by the yield considered as a result of complex interaction between soil (fertility), plants, climate, agro-productive activities of human in a certain territory in time. Therefore, the main task of the farming system is to obtain maximum, stable yields with high quality products.
This task can be achieved only through the most complete use of solar energy received per unit area in a given locality. The maximum possible absorption of solar energy is determined by fertility, i.e. the availability and abundance of terrestrial plant life factors.
All modern farming systems must be normative and comprehensive in content. System normativity is a technological model of soil fertility, which takes into account biological characteristics of crops and their yield levels, based on the dosage of intensification factors. The input parameters of the model are:
- arable layer thickness, cm;
- content of water-retaining macroaggregates, %;
- soil density, g/cm3;
- humus content, %;
- maximum permissible number of weeds per 1 m2;
- phosphorus P2O5 and potassium K2O content, mg/100 g of soil;
- acidity.
Reproduction of soil fertility is carried out by agrotechnical and reclamation measures on a normative basis using calculation and balance methods of fertility and yield programming.
For all the importance of economic and social relations in agriculture, they are still secondary in relation to the created yield. The biological nature of the crop, its quantity and quality are primary. The priority of biological and technological principles determines the agronomic essence and theoretical basis of farming systems. The amount of bound solar energy in the crop is the key indicator and condition of highly effective farming.
Influence of natural factors on bioproduction process is reflected in climate, soil, and plant. Each natural zone is characterized by certain amounts of physiologically active radiation, heat and atmospheric precipitation, their distribution during the year, the level of potential soil fertility, the species composition of crops and the nature of the created product. These are the primary objective conditions that limit the amount and quality of agricultural production.
Secondary and subjective factors influencing the bioproductive process and the value of the agricultural product include production technology, economic, social, and even historical conditions.
The connection between the primary and secondary factors is achieved through the cultivated plant, the yield of which is determined by the functioning of the farming system as a whole.
Thus, the theoretical basis of farming systems is the regulation of the production process in agrocenoses and soil fertility reproduction. The plant and soil are considered as one whole, as the main factor of farming sustainability. This unity is achieved through maximum adaptation to the specific conditions of the agrolandscape with normative ecological requirements. The essence of adaptation lies in creating agro-ecological conditions and consistent optimization of limiting factors that meet the biological and agrotechnical requirements of cultivated plants.
With regard to the conditions of a particular enterprise, the farming system should solve the following tasks:
- provide rational use of bioclimatic potential, land, plant, water, technical, labor and other resources;
- to create optimal conditions for the sustainable development and high productivity of crop production and other specializations of the enterprise in order to obtain the maximum quantity of quality products with minimum labor and resource inputs;
- to increase soil fertility;
- prevent the risks of erosion processes and environmental pollution.
Developing a farming system
When developing a farming system for the enterprise, the following requirements are taken into account:
- Intensity of farming. It is determined by the level of application of mechanization and automation, land reclamation, and chemicalization. To assess the effectiveness of intensification, indicators of growth of crop yields and productivity of forage lands, growth of labor productivity, reduction of costs per unit of production may be used.
- Cultivation technology should be soil-protective and energy-saving.
- Soil-protective, soil-improving and nature-protecting orientation.
- Extended reproduction of soil fertility through the use of fertilizers, grass sowing, intermediate crops, soil improvement methods of tillage, melioration. For this differentiated models of soil fertility are envisaged, taking into account soil type, planned crop yields, level of intensification.
- Economic feasibility. For the system of agriculture its place and importance in the general system of farming, specialization, correlation and combination with other areas, resource potential are determined.
Farming system is not uniform, it must be dynamic, i.e. constantly improving and adapting to external conditions.
Components of farming systems
The farming system as a whole consists of interrelated parts:
- organization of the territory of land use,
- organization of crop rotations,
- tillage systems,
- fertilizer systems,
- plant protection systems,
- crops cultivation technologies,
- seed growing system,
- reclamation measures,
- systems of control over the environmental situation,
- machinery system.
Organization of the land use territory of the farm
Scientifically justified organization of the land territory of an agricultural enterprise with all its land, water bodies, road network, industrial buildings and other facilities is the organizational and technological basis that unites all components of the agricultural system into a whole.
Organization of the territory of land use is developed on the basis of the project of intrafarm land management in which it is specified:
- the area of land use,
- number of separate land plots,
- availability of agricultural land,
- location of each land plot and crop rotation,
- characterization of soil and climatic conditions and vegetation cover,
- calculate bioclimatic potential and on its basis determine the possibility of cultivation of various crops and their potential yields;
- existing and planned specialization,
- the existing and planned specialization, and the organizational and production structure of the farm,
- the scale and pace of development of production,
- the average annual need for feed.
Separate attention is paid to expansion of arable area at the expense of low-productive forage lands and other lands, elimination of shallow contour and disconnection of lands. If there are meliorated lands, measures on intensification of these lands and programmed cultivation of high yields are determined.
Forms of land area organization can be rectangular, contour, contour-lane, contour-meliorative.
Organization of crop rotations
In different natural zones of Russia, the ratio of areas of prime land can vary significantly. Thus, in the southern regions the share of ploughed land reaches 80-90%, in the more northern regions up to 60-70% can account for forest and natural forage lands. Depending on the areas of arable and natural forage lands and the specialization of the agricultural enterprise the structure of the sown area and the system of crop rotations are developed.
Construction of crop rotations system is based on agroecological grouping of lands and structure of sown area. The minimum number of crop rotations must be equal to the number of agroecological groups of lands, and the maximum number is determined by technological expediency and economic efficiency. Land plots with limited suitability are used according to individual plan outside of crop rotation.
In the farming system the system of crop rotations must be the most optimal for each group of lands, ensuring ecological safety of the agrolandscape.
The system of crop rotations is developed on the basis of:
- rational structure of sown areas;
- adopted specialization,
- soil and climatic conditions,
- market conditions,
- fodder requirements,
- material and technical resources,
- production technology,
- the level of economic development of the enterprise.
The system of crop rotations should create optimal conditions for the organization of labor and the use of machinery.
Tillage system
Like the entire farming system, tillage should be soil-protective.
The construction of tillage system should be based on the requirements:
- Methods and technologies of tillage are determined by soil and climatic conditions, agrolandscape, biological features of crops, the degree of risk of erosion processes, hydrological conditions, and phytosanitary state of soil.
- Different-depth tillage of the soil in the rotation, which provides a reasonable alternation of the methods of mouldboard, non-moldboard, deep and surface tillage.
- Minimization of tillage, which is achieved by a good state of soil cultivation.
- Ecological, economic and soil-protective expediency of the applied methods and technologies of tillage, based on the balance of energy costs, their impact on the yield and fertility.
The system of tillage is developed for each crop rotation. The developed system of tillage is improved in the course of its use in the direction of its adaptation to the geomorphological and lithological conditions of the agricultural landscape.
Fertilizer system
Main article: Fertilizer system
Fertilizer system is a complex of agronomic and organizational measures, providing the use of organic and mineral fertilizers to increase yield and its quality, as well as the reproduction of soil fertility.
Fertilizer system, first, includes the development and implementation of organizational and economic measures for the production, procurement, purchase, transportation and storage of fertilizers. Including the identification of resources for local production of fertilizers, their procurement and storage, identification of the need for different types of fertilizers, reclamation materials, industrial mineral fertilizers, organization of their delivery, storage and application to the soil, the need to mix, fertilizer application in given proportions, taking into account fertility, crop requirements and agricultural engineering.
Secondly, the fertilizer system is a rational distribution of fertilizers in crop rotations and within them, the definition of optimum doses, timing and methods of use. This part of the fertilizer system is developed taking into account local soil and climate conditions and economic opportunities of the farm.
Fertilizer system in the crop rotation is a component of the fertilizer system, which is based on plans for the use of organic and mineral fertilizers, lime for crops in the rotation. These plans determine the doses, timing and methods of application for certain crops, taking into account the planned yields, biological characteristics of crops and their alternation, cultivation technology, soil, climatic and hydrological conditions, the properties of fertilizers, economic conditions of the enterprise.
In conditions of risk of water erosion development fertilizer system should take into account diversity of relief elements, their morphological characteristics, degree of soil washing out, runoff, lithological conditions.
Along with the landscape approach to the distribution of fertilizers take into account the effectiveness of their interaction with other elements of the farming system – tillage, crop rotation, timing and seeding rates. For example, nitrogen fertilizers can act as a decisive factor in minimizing tillage, the use of straw as mulch, reducing the proportion of bare fallow in the structure of sowing areas, deepening specialization. Under conditions of phosphorus deficit, the efficiency of bare fallow decreases, the loss of nitrogen from the soil due to its incomplete use by plants increases. Application of fertilizers is possible to regulate the rate of growth and development of plants at different stages of organogenesis, to accelerate or slow maturation, taking into account the timing of sowing and the formation of plant nutrition area using different methods and rates of sowing.
Row fertilizer accelerates the growth of the secondary root system of cereal crops, which often determines the formation of yields. Fertilizers can prevent or mitigate the effects of various stress factors on plants, improve adaptability to adverse conditions, drought and frost resistance.
Fertilizers influence plant resistance to diseases. For example, phosphate fertilizers promote root system development, increase disease resistance and resistance to pathogens. Potassium fertilizers help thicken cell walls, increase the strength of mechanical tissues, and inhibit the development of fungal diseases. Nitrogen fertilizers, on the contrary, stimulate the development of diseases.
The fertilizer system in the rotation depends on the agrochemical background of the soil and the requirements of crops. At the first stage of its development task is to regulate the nutrition of plants in the least balanced sections, such as optimization of phosphorus nutrition of cereals after fallow, nitrogen – in the background without plowing and minimum tillage, especially when leaving straw; top dressing of winter crops in spring and perennial grasses, starter row fertilization, etc. When achieving the necessary level of provision of cultivated land with mineral fertilizers, required for the development of anti-erosion measures, crop rotations with a certain ratio of crops, fallows, that is, optimization of farming systems. Further use of fertilizers should be based on the calculation of the planned yields of crops. To determine the maximum dose of fertilizers, if necessary, guided by the maximum profit, taking into account environmental constraints. Setting the optimum doses, depending on soil and climatic conditions and resource availability, it should be borne in mind that an excessive concentration of fertilizers on individual fields is not rational, as well as their dispersion over the fields.
Application of organic and mineral fertilizers in optimal doses is most effective.
Environmental negative effects are particularly acute in the production of vegetable crops, characterized by the greatest ability to accumulate nitrates and other residual chemicals. Therefore, vegetable production needs biologicalization, i.e. increasing the share of organic fertilizers in the fertilizer system, perennial grasses in crop rotations, the use of biological plant protection agents.
Excessive concentration of livestock waste poses a great ecological hazard. The main way of their use is the fertilization of perennial grasses.
Uneven application of organic and mineral fertilizers is a serious economic and environmental problem. Uneven application leads to uneven stem density in the field, uneven ripening, reduced product quality, increased leaching of nutrients. Losses from infiltration increase with increasing doses of fertilizers. According to T.N. Kulakovskaya, in Belarus in years with excessive moisture the loss of nitrogen from leaching on sandy soils reaches 60 kg/ha, on loamy sands – 20-25 kg/ha, on loamy – 10 kg/ha. In years with normal moisture these figures are reduced by about 2 times. Nitrogen losses in the form of gaseous compounds are 10-30% of the applied nitrogen (Mineev, 1984).
To prevent nitrogen losses, and consequently to reduce irrational costs, it is necessary to optimize the doses, forms and timing of nitrogen fertilizers for each crop of the crop rotation, to distribute and incorporate them evenly in the soil.
Intensification of farming leads to an increasing role of soil organic matter. In modern farming it determines soil buffering capacity, absorption capacity, biological activity, transformation and inactivation of pesticides and other agrochemicals, the possibility of using minimum tillage and reducing energy costs, increases the stability of farming in adverse weather conditions.
According to generalized data, to maintain a deficit-free balance of humus in the arable layer of various soils of Russia it is necessary to make on average 6.5 t of standard manure per 1 ha, in the Central Black Earth zone – 7.0 t/ha, in the Central region – 5.0 t/ha, Volgo-Vyatsky – 11.6 t/ha, North Caucasus – 5.8 t/ha
Plant protection system
Plant protection system is a system of management and regulation of phytosanitary potential of crops and soil. The number of pests and weeds is regulated by a set of interrelated organizational, agrotechnical, biological and chemical measures.
The rational system of plant protection is based on the accounting of the number of pests and weeds, and the forecast of their distribution. The forecast serves as the basis for planning the scope of work, determines the need for agrotechnical, chemical, biological means, machinery, material and labor costs.
The purpose of the plant protection system is to preserve harvests by means of regulatory mechanisms within agroecosystems to maintain the number of pests and weeds at the level of ecological and economic thresholds of harmfulness.
Under modern agro-landscape farming systems, biological and cultural methods of plant protection gain leading importance. Scientific validity of all parts of the farming system allows you to build the most effective and economically and environmentally rational system of plant protection.
Organizational and economic (cultural) measures of plant protection include: crop rotations, use of quality seeds, zoned varieties resistant to diseases and pests, compliance with optimal timing and quality of technological methods, preventive measures.
Agrotechnical methods of plant protection, as a rule, are used in conjunction with the system of tillage: during the pre-sowing, post-sowing and post-harvest tillage.
Chemical plant protection measures include seed dressing, spraying of soil and crops with pesticides or herbicides, disinfection of storages and currents, etc. The use of chemical methods requires accurate compliance with the timing, doses and methods of application of preparations, requirements for environmental protection and safe work practices. The role of chemical methods increases with increasing specialization of agricultural production and the level of intensification. Rejection of their use leads to a significant decrease in the effectiveness of fertilizers and land reclamation, however, chemical methods should be considered as an exceptional method when others cannot bring sufficient results.
Biological method of pest and weed plant population control involves maintaining the density of natural entomophages with biological preparations, introduction of parasites or predators, artificial increase in the number of entomophages, use of entomopathogens, ferromones, insect hormones, repellents, attractants, release of sterile insects, etc.
Proper choice of biological, agrotechnical, chemical and other means of plant protection determines the effectiveness of the plant protection system.
Crop cultivation technologies
Crop cultivation technology is a technological complex of practices aimed at creating optimal conditions for the growth and development of plants. It includes techniques performed from the moment of clearing the field by the predecessor to the harvesting. Techniques include basic and pre-sowing tillage, fertilizing, preparation of seeds for sowing, seeding, care of crops.
Cultivation technologies are developed taking into account agro-ecological requirements of crops and varieties to growing conditions, as a consistent overcoming of factors limiting the yield and quality of products and creation of optimal conditions for specific conditions of the enterprise (material and technical resources, economic and environmental). Like other elements of the farming system, cultivation technologies must be closely linked with other elements.
Intensive cultivation technologies presuppose a fundamentally different set of technical, agrochemical, and biological means from traditional ones. These technologies involve not only the creation of an optimal level of mineral nutrition of plants and an appropriate system of plant protection, but also the quality of all field work. Application of intensive technologies implies control over the content of pesticide residues in the soil and grown agricultural products.
The system of use of natural forage lands
System of use of natural forage lands – a system of arrangement of hayfields and pastures, which includes measures for their rational use taking into account the needs for forage and soil protection from erosion. The activities of the system include:
- organization of hayfield and pasture rotation,
- care of hayfields and pastures,
- re-creation of meadows,
- organization of grass seed production, etc.
Seed production system
The seed production system, or the organization of on-farm seed production, includes:
- seed production planning,
- technologies of cultivation of field crops for seeds,
- varietal and seed control,
- postharvest processing,
- seed storage,
- seed preparation for sowing,
- varietal changes and varietal renewal,
- establishment of insurance and transfer (for winter crops) seed funds.
Sowing is carried out with seeds of high (not less than fifth) reproductions of the first and second classes of sowing standard.
When planning seed production, one determines the sources of seed supply, the procedure for variety change and variety renewal, the yield of conditioned seeds, the structure of sown areas, seeding rate, the creation of basic, insurance and transferable seed funds, and the material and technical support of seed production.
Technologies of cultivation of agricultural crops for seeds should be developed taking into account the fact that the high saturation with pesticides and mineral fertilizers, non-storm culture can lead to deterioration of germination and growth power of seeds and sometimes to decrease the quality of the harvest.
Cultivation of high-quality seeds of released varieties and hybrids involves varietal control, the purpose of which is to determine the conformity of crops to the variety, the degree of varietal purity (typicality) and suitability of the crop as a whole for seed. The main method of varietal control is field testing, which determines the varietal purity, typicality, weediness of crops by difficult to separate cultural and weed plants, establish the presence of quarantine, noxious and poisonous weeds, pests and diseases, control the implementation of requirements of growing technology and maintaining varietal documentation.
Quality control of seeds is subdivided into on-farm and state. On-farm control is carried out during harvesting, when seeds come to the field, during postharvest handling and storage. The state control is carried out by the State Seed Control Service.
For the purposes of state seed control, samples of seeds are taken at the beginning of storage and before sowing and submitted to the regional seed control inspectorates to confirm their quality.
Variety change consists in replacing old low-yielding and low-quality varieties with new ones. Varietal renewal is the periodic replacement of seeds of low reproductive varieties already involved in production with higher reproductive varieties. The basis for renewal is elite. The frequency of varietal renewal is once every 4-6 years.
There should be no varietal renewal during the planned introduction of new varieties into production. The creation of a new variety should take place over a period during which the deterioration of variety qualities and yield properties of the old variety reaches the threshold of economic importance. However, in practice, permanent varietal change in 4-5 years is not yet possible.
Ameliorative measures
Ameliorative measures are aimed at radical improvement of land and microclimate of lands. They include: irrigation, drainage, arrangement of reservoirs, chemical melioration, cultural and technical works, land reclamation, meliorative tillage, agro-forest-melioration, etc.
Irrigation regulates water supply to plants and promotes creation of favorable water, nutrient, air, heat, salt regimes of soil. Irrigation systems can be permanent (regularly operating), temporary, created for irrigation during the season and once operating, or liman irrigation, for example, for the retention of melt water.
Special types of irrigation include fertilizer irrigation, warming irrigation, which uses waste water from thermal stations, geysers to irrigate fields, greenhouses, washing water to dissolve and wash out harmful salts from the root layer of soil.
Dewatering of over-watered and waterlogged lands allows to regulate water-air regime of root layer. The main methods of dewatering are:
- acceleration of surface and subsurface runoff on watershed boundaries and gentle slopes with heavy soils and atmospheric type of water supply;
- interception of surface and ground water entering the drainage area;
- lowering of groundwater table with high level of its standing;
- warming reclamation in permafrost conditions, where over-watering leads to deep freezing of top-soil soils;
- two-way dewatering and humidifying regulation of soil moisture.
The main methods of drainage:
- single channels and systematic open network on permeable soils;
- open canals or closed horizontal drainage in combination with agromeliorative measures on poorly water permeable mineral soils;
- closed drainage of low thickness peatlands, underlain by poorly permeable soils and used for arable land;
- preliminary drainage of thick (more than 1.5-2 m) peatlands by open channels and mole drainage with subsequent laying of closed drainage after peat settling;
- drainage of peatlands by open channels in combination with sparse closed drainage when using them for arable land and pastures.
Agro-forest-meliorative measures are aimed at soil protection from erosion processes, improvement of microclimate and water regime. They include creation of field-protecting, water-regulating, pasture-protecting forest belts, “green zones” on pastures, forest belts on irrigated areas, afforestation of ravines, gullies, sands, banks of rivers and reservoirs, steep eroded slopes.
Environmental control system
The system of environmental control includes monitoring the state of soil cover, soil fertility of agrolandscapes, surface and ground water, perennial vegetation, natural nesting places of birds and insects, accumulation of nitrates and pesticides in products and environmental objects.
On erosion-prone and eroded lands, a soil-protective set of measures is provided: soil-protective crop rotations and methods of tillage, ameliorative measures.
Environmental protection measures are developed for each element of the farming system.
System of machines
The machine system should strive to provide comprehensive mechanization of cultivation and harvesting of crops, replacement of manual labor in all technological operations with mechanized. Complexes of machines should be formed in accordance with the technology of crops cultivation in relation to specific soil and climatic conditions.
The machinery system should provide for an increase in the power capacity of tractors, an increase in the working speed and working width of units, the use of universal and combined machines, progressive forms of organization of field work and improvement of the qualifications of specialists.
Labor organization
Organization of labor in crop production consists in:
- organization of labor collectives and assignment of crop rotations, fields and natural forage lands, labor processes;
- establishment of work and rest regimes, labor remuneration.
Production collectives are formed in accordance with the specific economic and natural conditions of the enterprise. There are various modern forms and approaches in management and organization of labor, based on domestic or foreign experience. The effectiveness of forms of labor organization is determined by a wide range of factors.
Zonal features of farming systems
There are several natural-climatic zones in Russia, and the farming systems in each of them have their own features. In particular, there are farming systems:
- Non-Black Earth (taiga-forest) zone;
- Central Black Earth zone;
- Volga region;
- Northern Caucasus;
- steppe and forest-steppe regions of Siberia;
- Far East.
Farming systems of irrigated regions are considered separately.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Fundamentals of Agronomy: Tutorial/Y.V. Evtefeev, G.M. Kazantsev. – M.: FORUM, 2013. – 368 p.: ill.
Land recultivation
Land recultivation (restoration) is a complex of engineering, reclamation, agro-technical and other measures aimed at restoring biological productivity, economic value of disturbed lands and improving environmental conditions.
Disturbed lands
Disturbed lands – lands which have lost their original economic value or have become a threat to the environment by changing the soil cover, hydrological regime and formation of anthropogenic landscape as a result of human industrial activity.
61% of disturbed lands fall on the territories of mineral deposits development, their processing and geological prospecting works, 27% – on peat extraction works. In 1997 the area of disturbed lands from mining operations and geological prospecting works was about 700 thousand ha, peat extraction – more than 300 thousand ha.
According to the data of the State Research Institute of Land Resources, depending on mining and geological conditions of mineral deposits from 2,6 to 43 hectares of land are disturbed per 1 million tons of surface coal mining, from 14 to 640 hectares of iron ore, from 76 to 600 hectares of manganese ore, from 22 to 77 hectares of phosphorites. Land disturbance with deterioration of the environmental situation may also occur during underground development of deposits due to surface deformation, such as sinkholes, storage of excavated rocks, pollution by industrial emissions, oil products, sewage water, drilling fluids and cuttings during drilling and well operation.
Land disturbance occurs when laying main pipelines, building roads and canals. At the same time, landscapes and land use structure deteriorate, erosion processes intensify, the balance of ground and surface waters is disturbed, nearby lands become waterlogged or dry out, and their productivity decreases.
Land disturbance is predominantly pronounced in areas with high population density and developed industry, where the reserves of introducing new lands into agricultural use are almost exhausted. For this reason, the issue of including disturbed lands subject to reclamation in the total balance of agricultural land is relevant.
According to the State Land Records, as of January 1, 1999 the acreage of disturbed lands in Russia made up 1.19 million hectares. The main part of disturbed lands is concentrated in the areas of intensive farming with high population density.
In Russia there is a tendency of increasing the rate of land disturbance in Western and Eastern Siberia, in the Far East by 15-20% per year, in the Central Black Earth zone, especially in Kursk and Belgorod regions. Over 30 thousand hectares of valuable chernozem and gray forest soils have been withdrawn from land use in these zones for the iron ore industry.
Land recultivation (restoration)
Recultivation makes it possible to return disturbed land to agricultural land, to use it for forests, water bodies, recreation areas, housing and industrial construction. Recultivation can be subjected to excavation of quarries, peat mines, rock dumps of mines and quarries, sites of drilling wells, etc.
The problem of recultivation in conditions of a constantly increasing area of disturbed lands acquires great socio-economic and ecological significance. The issue of recultivation should be included in the projects for the construction and reconstruction of enterprises, in the schemes of land management of territorial and production complexes.
If scientifically grounded recultivation technologies are followed it is possible to turn the disturbed lands into highly productive land within 3-5 years. More than 2,200 thousand hectares of disturbed lands have been reclaimed in Russia.
Some rocks are characterized by effective fertility. Achievements of modern agriculture, developed technologies of creation of anthropogenic soils, methods of biological development of recultivated areas and management of soil formation process in anthropogenic landscapes allow to use these rocks in order to create productive farmlands as well as to improve ecological conditions in relation to a specific natural zone or territory.
Depending on the requirements of plants to growing conditions, several ecological and trophic groups of plants have been identified:
- megatrophs,
- mesotrophs,
- oligotrophs
- eurythrophs.
Megatrophs are agricultural crops with the highest requirements for soil (edaphic) environment: rye, wheat, oats, barley, corn, sorghum, millet, buckwheat, sunflower, castor bean, water melon, Agropyron, Bromus.
Mesotrophs – crops less demanding to the soil environment: peas, china and other grain legumes.
Oligotrophs – crops that can grow under specific conditions, for example, under high acidity and salinity of soil, unfavorable air or water regimes of soil. They are divided into halophytes, argyllophytes, acidophytes, psammophytes, metophytes and others.
Eurythrophs are crops with symbiotic nitrogen fixation ability which allows to ensure productivity at the level of old undisturbed soils. They include: alfalfa, sainfoin, elm, sweet clover, Lotus, astragalus and other leguminous grasses.
The thickness of the recultivated soil layer is determined depending on the biological characteristics of crops, the composition of rocks and the bulk layer. For black earth soils, for example, it is from 1-1.5 to 2-2.5 m, which allows to create conditions for the development of the root system and plants close to normal.
Rocks with phytotoxic properties, i.e. containing excess of readily soluble salts, pyrite, mobile forms of iron and aluminum, rocks of early geological ages, such as the Cretaceous and Jura Mesozoic, Carboniferous and Devonian Paleozoic with unfavorable agrophysical and agrochemical properties are the most problematic for recultivation for agricultural land.
For specific and difficult conditions of the Podmoskov coal basin, where phytotoxic rocks in the overburden strata make up to 40-60%, technologies have been developed to create agricultural plots with yields at the level of zonal indicators in place of disturbed lands. For example, in the Novomoskovsk district of the Tula region, the recultivated lands yield up to 4-4.5 t/ha of grain.
At the quarries of the Moscow region the arable land is created by applying a layer of glauconite sand on the surface of the dumps. Application of nitrogen fertilizers allows to increase the yield of these lands by 30-50%, compared with conventional soils.
The abandoned lands can be used to create large specialized agricultural enterprises.
Egoryevskoye phosphorite deposit is a good example of successful land recultivation. In the conditions of the Kursk Magnetic Anomaly positive results were obtained from the formation of artificial soils on the waste rock and adjacent low-productive lands, which was carried out by applying a layer of chernozem and cultivation of potentially fertile rocks.
Overburden rocks in the zone of the Kursk Magnetic Anomaly according to the degree of suitability for development and introduction into agricultural turnover are divided into:
- High quality rocks suitable for the cultivation of legumes and cereal-legume grasses, some field crops. These include loess-like loams, loess, soil mixture, loams with other rocks.
- Rocks of medium quality, suitable for afforestation and grassing: sands, soil mixture of silts with chalk, loam, marl, colluvium clays.
- Low quality rocks, suitable for afforestation and reforestation after preliminary improvement: Devonian deposits, chalk.
- Pyrite-bearing rocks, highly acidic, unsuitable for biological development.
Stages of land recultivation
Land recultivation is carried out in two stages.
- Technical recultivation consists in preparation of lands for further target use in agriculture: restoration of fertile layer, leveling the surface, removal or neutralization of toxic substances for plants, construction of reclamation and other structures.
- Biological reclamation – measures aimed at restoration of soil fertility, including agrotechnical and phytomeliorative methods aimed at restoration of flora and fauna.
Biological recultivation can be agricultural and forest.
Agricultural recultivation involves the creation of hayfields, pastures, arable land, perennial fruit and berry plantations on the restored land.
Forest recultivation involves planting tree crops on disturbed lands to create forests of different purpose and value.
Methods and techniques of land reclamation are determined by physical and geographic, economic features of the area, mining technologies, properties of minerals, physical and chemical properties of overburden rocks and other conditions. According to legislative requirements, all industrial organizations are obliged to remove the fertile humus layer from the land plots allocated for mining and use it for recultivation. For agricultural use, the top fertile layer with a humus content of at least 1-2%, for black earths 2-2,5% is removed. The humusized layer of soil is stored in stacks or bunches up to 10-15 m high. To protect the stacks from erosion processes they are planned and sown with grasses.
When recultivating lands for agricultural use special attention is paid to creation of a fertile arable layer, optimization of soil treatment, selection of cultivated plants.
Priority objects of recultivation include exhausted peatlands. The drainage network on them is restored in advance taking into account the subsequent agricultural use. Then, a set of cultural and technical works is carried out. Exhausted peatlands can be successfully used for cultivation of agricultural crops and hayfields.
Currently, for all economic zones of the country there are developed methods of disturbed land recultivation, which allow to solve a wide range of issues on cultural transformation of anthropogenic landscapes. However, not all sectors of the economy pay sufficient and timely attention to land recultivation, and the removed fertile soil layer is not fully used, and the volumes of its storage are increasing. The volumes of reclamation of disturbed lands in Russia are insignificant. For example, in 1996 160.1 thousand hectares of disturbed lands were reclaimed.
Methods and technologies of disturbed land recultivation
To perform biological recultivation of disturbed lands it is important to take into account agrochemical and water-physical properties of overburden rocks. That allows to reduce the cost of implementing a set of works on recultivation: covering the surface of dumps, cutting terraces, creating access roads, determining the steepness of slopes, etc.
Modern recultivation technologies developed for different natural zones of Russia, taking into account biological features of crops, compositions of overburden rocks and soil-climatic conditions, establish optimal capacities and designs of recultivated layers, assortment of crops and determine ameliorative crop rotations, technologies of crops cultivation and cultivation of productive forest plantations. For example, for the subzone of southern black earths the recultivated layer thickness is 1-1,5 m, ordinary – 1,5-2 m and typical black earths – 2,5 m.
Application of the humus layer
Recultivation of disturbed lands for arable farmland begins after the stabilization of planned rocks, after which a humus layer of 40-50 cm is applied. In some cases the thickness of the humus layer can vary depending on the underlying rocks and the planned type of economic use. For example, when using techno-soils for perennial leguminous grasses, perennial plantations and leguminous crops, it can be reduced or replaced by a local application of the humus layer. For vegetable crop rotations, on the contrary, it can be increased.
The thickness of the created humus horizon strongly affects crop yields. For example, in the conditions of the Kursk Magnetic Anomaly, the maximum crop yield of cultivated crops was obtained when the humus layer with the thickness of 60 and 80 cm was applied to the rocks, and the maximum increase in every additional 20 cm is accounted for by the thickness of 40 cm.
Table. Crop yields depending on the thickness of the applied layer of black earth and bedrock (by A.M. Burykin, average for 4 years, 1986), t/ha
With the same thickness of applied black earth, grain yield on loam is significantly higher than on chalk. Alfalfa, barley and millet are more responsive to the increased thickness of the applied layer, while winter rye and sainfoin are less responsive.
According to the Dnepropetrovsk Agricultural Institute, cereal yields on recultivated plots with a layer of black earth of 30-50 cm are close to the yields on old ploughed lands. Increasing the thickness of the layer applied up to 80-90 cm increases the yield of winter wheat by 2 times, while 10-20 cm reduces the yield to 10-30% of the yield obtained on the old arable lands.
One of the important methods of recultivation is the use of ameliorative crop rotations, in which a large proportion falls on soil-improving crops such as lupine, melilot, alfalfa, sainfoin. For example, in the conditions of the Kursk Magnetic Anomaly a crop rotation is used for development of arable lands: the 1st-3rd years – lucerne with plowing, the 4th – winter crops, the 5th – row crops, the 6th – cereals with undersowing of perennial grasses. In process of development and improvement of state of cultivation of recultivated lands intensive type crops are introduced into crop rotation.
To increase the fertility of recultivated lands, green fertilizers in combination with increased doses of mineral and organic fertilizers, rotary tillage tools, such as rotary plows, milling machines, combined aggregates, allowing to create a deep homogeneous soil layer are used. For example, in the Nikopol manganese basin the use of N90P90 with a thickness of the bulk black earth layer of 30-40 cm allowed to get a crop of winter wheat, as well as on the old-soil lands.
In PA “Phosphates”, Moscow region, on arable land created by applying a layer of glauconite sand on the surface of the dumps, the application of nitrogen fertilizers allowed to obtain a yield by 30-50% higher than on zonal soils.
The method of direct improvement of the state of cultivation
The method of direct improvement of the state of cultivation is a method based on the application of mineral fertilizers, application of green fertilizers and sowing of perennial grasses.
Application of the full mineral fertilizer N60P60K60 on techno-soils of the Kursk Magnetic Anomaly allowed to increase barley yield by 1,3 t/ha, or 186%; application of N90P90K90 under millet increased it by 1,2 t/ha, or 276%.
Table. Yield of spring wheat on different species depending on method of cultivation (by A.M. Burykin, average for 2 years, 1986), t/ha
According to the results of field experiments, bacterial fertilizers show high efficiency. For example, inoculation of legume grass seeds with rhizotorfin increased hay yield of clover by 0.63 t/ha, sainfoin by 2.43 t/ha, and alfalfa by 2.48 t/ha. Protein content of the fodder increased by 0,5-1,3%, and the collection of protein from 1 ha was 1 000, 1 901 and 1 526 kg, respectively (Stifeev A.I.).
There is an experience in land reclamation for creation of irrigated pastures. For this purpose, grass mixtures of blue alfalfa, hedgehog and meadow bluegrass are used. Yield of green mass for two mowing in the first year of use is 18.0 t/ha. In the zone of sufficient moisture, the dry mass yield of the grass mixture of twigs and brushwood was 1.48 t/ha, which is higher than on undisturbed natural pastures.
Optimization of tillage, mulching with straw and ash, and irrigation have a favorable effect on the process of soil recovery.
As soil fertility is restored, crop yields reach normal levels. Valuable cereal crops are introduced into crop rotation, as a rule, after 3-4 years of biological recultivation.
Hayfields and pastures can be created on dumps without application of humus layer. According to A.I. Stifeyev’s researches it is possible to grow perennial leguminous grasses on overburden rocks of Kursk Magnetic Anomaly in the first 3-5 years which show high productivity with good fodder qualities. It is most rational to use dumps immediately after their backfilling and leveling for fodder grasses, since there is still little weed vegetation, and the loose state of rocks contributes to the germination of seeds and growth of grasses.
When using techno-mixtures and loess lithozems for hayfields and pastures, the following schemes of crop rotation are used:
- Year 1-3 – perennial grasses (with plowing), year 4 – winter rye, year 5 – millet with undersowing of perennial grasses, years 6-8 – perennial grasses;
- In years 1-2 – melilot with embedding of green mass; in year 3 – winter rye; in year 4 – millet with undersowing of perennial grasses; in years 5-7 – perennial grasses.
Tillage for grasses on overburden rocks in the first years of development includes harrowing, cultivation, milling, which provide high yields at 15-20% less cost than plowing.
According to A.I. Stifeyev’s data the grassing of loess lithozems and hydro-dumps allows to receive about 16 t/ha of green mass of melilot and more than 20 t/ha of lucerne.
Recultivated rock dumps and hydro dumps in the Magadan region in permafrost conditions give 15 t/ha of green mass of oats and peas, which is 10-20 times higher than the yield of wild grasses on natural fodder lands. At the same time favorable water and thermal regimes are provided on the recultivated lands, soil freezing is eliminated. In these conditions land recultivation can be more profitable than development of new lands.
Earthing method
Earthing method – covering low-productive lands with a fertile humus layer of soil of different thickness, which allows obtaining crop yields 2.5-3 times higher.
For example, on shale ash dumps formed from bulk material, they create cultural hayfields. The properties of ash dumps depend on the “age”, the density of the deposit and the chemical composition of ash.
The reaction of ash dumps is often strongly alkaline, with alkalinity increasing with depth. Thus, the pH of 0-5 cm layer is – 7,9-9,7, at a depth of 30 cm – 12,3-12,6. The chemical composition of oil shale ash contains 32-35% calcium oxide and 24-30% silicon oxide, sulfur, magnesium, iron and carbon compounds. Granulometric composition of oil shale ash is close to sand and coarse dust fraction, with density of 0,9-1,28 g/cm3.
The content of nutrients in ash is insufficient, and the ratio is not conducive to plant growth. Nitrogen compounds are practically absent, mobile forms of phosphorus are very small – 0,2-0,4 mg/100 g, but a lot of exchangeable potassium – 135-760 mg/100 g of soil.
Therefore, to create cultural meadow on ash dumps, peat or soil is used, which are applied in a layer of thickness of not less than 10 cm. With such a layer it is possible to carry out harrowing with light harrows and grass maintenance works. If the ash dump only needs to be grassed, it is enough to create a layer of humus 3-5 cm.
Mixtures of red fescue (Festuca rubra), bromegrass (Bromus inermis), hedgehog (Dactylis glomerata), meadow clover (Trifolium pratense) and creeping clover (Trifolium repens) are used for laying cultural meadow on ash dumps. The root system of cereal grasses is located in the upper layers of the soil, while that of legumes penetrates deeper. Legumes, binding atmospheric nitrogen, provide it to themselves and to cereal grasses.
For biological recultivation of disturbed lands, planting of woody and shrub vegetation, including economically valuable trees and shrubs (berry, nut-bearing, medicinal from among local and introduced species) on overburden rocks is used.
Forest plantations on the dumps improve the ecological condition of the territory, reduce the manifestation of erosion processes, accelerate the soil formation process and the formation of biocenoses.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Erosion control measures
In modern agriculture, a number of erosion control measures have been developed and applied to protect the soil from erosion and prevent its development and spreading. The erosion control techniques (measures) are the components of anti-erosion complex of measures.
Integrated application of organizational, agrotechnical, agrochemical, ameliorative and hydro-technical erosion control measures is the most effective. It ensures the preservation of land fertility, growth of crop yields, stability and profitability of agriculture.
The main methods of soil-protecting complex
The main methods of soil-protecting complex:
- Anti-erosion measures:
- grassing of heavily washed out slopes;
- soil-protective crop rotations;
- contour-tillage;
- forest reclamation;
- hydro-reclamation structures, e.g. dams, water-regulating swale
- systems, swift-flowing streams;
- strip rolling and snow blanketing, use of snow retention shields.
- Anti-deflation measures:
- cereal-fallow, cereal-row crop rotations with a short rotation;
- buffer strips of perennial grasses;
- strip planting of bare fallows and row crops;
- strip-till farming;
- flat-cutting tillage;
- sowing cereals with stubble seeders;
- wood reclamation;
- regular irrigation.
- Anti-erosion and anti-deflationary measures:
- soil and water conservation land management of the territory;
- grassing of heavily washed out slopes;
- cereal-grass, cereal-fallow and cereal-row crop rotations;
- strip-tillage placement of bare fallows, row crops and perennial grasses;
- flat-cutting across the slopes after cereal crops;
- hollowing, for example, after perennial grasses and corn, ploughed land and fallows;
- slitting of perennial grass;
- mulching the soil with chopped straw;
- forest reclamation;
- hydrotechnical constructions;
- agrohydromeliorative soil-protective complex in the watershed.
The leading role in erosion control is given to the systems of tillage of soils subject to water erosion and tillage of soils subject to wind erosion.
Forest reclamation techniques
Forest plantations in erosion-prone areas, depending on their purpose, are divided into:
- water-regulating,
- near-wash,
- near-gully,
- field-protective,
- pasture protective.
In addition, there are water-protective plantings located near rivers, ponds and reservoirs, as well as group and cluster plantings. In some cases there is continuous afforestation of slopes, sands, wash and gullies.
In open steppe and forest-steppe regions with active and strong winds the main purpose of forest belts is to reduce the speed and turbulence of erosive wind flows. Wind weakening contributes to protection of soils from blowing out in summer and winter periods, snow retention, increase of soil and air moisture, improvement of microclimate.
According to VNIALMI data, the system of forest belts allows to accumulate 1.5-2 times more snow on the fields, air humidity in the ground layer increases by 5-10%, moisture losses from evaporation decrease by 20-30% than in the open steppe.
The anti-erosion and reclamation efficiency of forest plantations depends on their design. In steppe areas, openwork and blown narrow-row strips of 3-5 rows are used.
When forest reclamation measures in areas of water erosion development it is important to take into account peculiarities of terrain, as incorrect placement of forest strips may lead to increased runoff, increased washout and erosion of soil, gully formation.
Water-regulating forest strips are created on relatively steep slopes with a slope of more than 2-3°. Their main purpose is to disperse and absorb surface runoff of meltwater and stormwater. They are placed in strips in 4-7 rows across the slope or horizontally, with a distance of 200-350 m between strips, depending on steepness and susceptibility of soil to erosion.
Near-wash forest belts are designed to protect the adjacent arable land from the destructive action of erosion processes and for more effective snow distribution and moistening of fields. As a rule, they are designed in openwork design with width of 12-21 m.
Near-gully forest belts are created to strengthen the growing tops of gullies. They can cover the whole systems of gullies and tops. Gully tops are secured by diking in advance.
Pasture protection forest strips are placed on slopes, taking into account the relief, soil damage by erosion, the direction of runoff and prevailing winds. Design of strips is openwork and openwork-blown with width of 9-18 m and distance between main strips from 200 to 350 m.
Cluster-group and continuous afforestation is carried out if the territory is very indented by ravines and on sands.
Hydrotechnical anti-erosion structures primarily include:
- earthen water-retaining, water-regulating shafts and ditches used for water retention and diversion to reinforced water receptors, hollows, etc.;
- apical (head) structures in the form of concrete, wooden, brick and other flumes, swift currents, drops, cantilevers, etc.;
- bottom structures along the beds of hollows and gullies, preventing further erosion of the bed;
- bank protection and mudflow prevention structures;
- ponds and reservoirs.
Phytomeliorative techniques
The natural vegetation cover and dense cover of cultivated plants can serve as effective soil protection against water and wind erosion. Cultivated plants with high soil-protective properties include perennial and annual grasses, winter and spring cereals, buckwheat, peas and other continuous crops. To enhance soil-protective effect, the seeding rate is increased, and cross-row and narrow-row sowing methods are used.
On steep slopes, perennial grasses are grassed. For example, in the Belgorod experimental station, when grassing steep slopes of 10-12°, the hay yield is 2.5-3 t/ha. In Liskinsky and Ostrogozhsky districts of Voronezh region, the hay yield on steep slopes is up to 4 t/ha. In Belgorod Region, grass mixtures of alfalfa, Onobrychis, awnless bromegrass (Bromus inermis) and meadow fescue (Festuca pratensis) are most productive on sloping lands.
In eastern Russia, Agropyron ? (broad-banded) and narrow-banded (Agropyron desertorum), Melilotus officinalis and Sainfoin (Onobrychis arenaria). Their mixtures yield large harvests of high-quality hay or green mass.
Perennial grasses and sprouted winter crops have high soil-protecting ability against blowing out; to a lesser extent, it is manifested in early spring crops, and the lowest – in late row crops.
Soil-protective crop rotations are crop rotations designed to protect soils from water erosion on slopes greater than 5°, where soil washout can reach 15 t/ha per year, and wind erosion, for example in open steppe where wind speed near the surface is more than 3-4 m/s.
On lands subject to water erosion, crop rotation fields are placed with the long side across the direction of the slope in order to cultivate the field across the slope.
Soil-protective crop rotations are based on the property of some crops in combination with special methods of tillage and placement of crops to protect the soil from erosion.
Buffer strips
Buffer strips are a method of sowing crops that serves to accumulate snow in winter and reduce runoff and the development of water and wind erosion in spring. Sowing of perennial and annual grasses, winter and spring cereals, sunflower, Sudan grass and other crops is used for buffer strips. Width of buffer strips and distance between them is determined by steepness of slope, degree of manifestation of erosion processes.
In practice, on slopes of 6-8° the width of buffer strips is 4-6 m (3.6-7.2 m), with the distance between them 30-40 m. On slopes of lesser steepness the distance is up to 50-100 m and on steeper slopes it is 10-30 m with the width of strips of 10.8 m. To prevent wind erosion, the width of buffer strips is determined depending on the degree of soil deflation and wind speed.
A system of soil protection tillage
The tillage system should provide each field and plot with soil protection from erosion processes and high and sustainable yields of crops throughout the year.
General and special (additional) tillage methods are referred to soil-protecting practices.
Examples of common anti-erosion methods of main tillage:
- plowing across the slope;
- stepped plowing with the use of plows, where even bodies are set 10-12 cm deeper;
- plowing with simultaneous formation of anti-erosion nanorelief on the field, such as furrows, ridges, holes, intermittent furrows;
- plowing with a deepener or a plow with notched bodies;
- non-moldboard plowing;
- flat-cutting, deep loosening with stubble retention;
- combined mouldboard and non-moldboard plowing;
- strip loosening;
- slitting of winter crops, perennial grasses, natural hayfields and pastures;
- minimum tillage;
- chiseling;
- mole tilling;
- contour tillage;
- cultivation with deep looseners, flat-cut cultivators, needle harrow, rod
- cultivators and other erosion control tools.
The above list is not limited to the listed techniques, which can be supplemented by others, taking into account soil and climatic conditions of each zone.
According to studies conducted in erosion-prone zones of Russia, deep autumn plowing allows increasing water reserves by 20-30 mm by reducing surface and subsurface runoff and increasing crop yields by an average of 10-15%, especially in years of drought and in areas with insufficient moisture.
Alternating tillage methods
Alternation of non-moldboard tillage at a depth of 30-32 cm with plowing at a depth of 20-22 cm with creation of rollers on the surface of plowed soil is an effective method of erosion control tillage.
Alternation of deep plowing at 30-32 cm, if the humus horizon allows, with ordinary plowing at the depth of 20-22 cm is also effective.
Application of non-moldboard implements on sloping lands allows to reduce dramatically melt water runoff and soil washout. At the same time cereal crops yield increases by 0.2-0.4 t/ha. Deep loosening (chiseling) and plowing across the slopes is used on heavy soils.
In the Non-Black Soil Zone, sod-podzolic soils usually use mouldboard tillage combined with surface tillage, in the rest of the European part of Russia – combined tillage combining mouldboard tillage with surface and flat tillage, in Siberia – flat tillage combined with surface tillage.
Contour tillage
Contour tillage – tillage in the direction close to the course of the horizontals with the transverse movement of aggregates, is a part of the contour organization of the territory.
The Research Institute of Agriculture of the Central Black Earth Belt named after V.V. Dokuchaev and Voronezh State Agrarian University proposed a contour-buffer system consisting in strip alternation of crops and buffer strips of perennial grasses in soil-protective crop rotations.
The works of Y.I. Potapenko of the All-Russian Research Institute of Viticulture and Winemaking, who proposed a set of anti-erosion measures on the contour-belt basis, were widely spread.
Special techniques
Special (additional) methods of anti-erosion tillage include: furrowing, hollowing, mole cutting, creation of rollers, slitting, etc.
Creation of rolls and furrowing of ploughed soil are used on one-sided and levelled sloping lands without troughs. Creation of rollers is carried out simultaneously with plowing with the use of the extended mouldboard mounted on one of the plough bodies. Simultaneously with plowing of furrow it is possible to perform intermittent furrowing. For this purpose, ploughs with special three-blade bridging-makers mounted on them are used. For intermittent furrowing, ploughs are equipped with ПРНТ-70000 and ПРНТ-90000 devices.
The depth of the furrows on the cultivated field is 25-30 cm and the distance between them is 4-10 m. The steeper the slope, the more often make furrows.
According to the data of experimental institutions in Bashkortostan, furrowing of the furrow reduces soil washing out, increases its moisture and the yield of spring wheat by 0,15-0,4 t/ha.
On many agricultural enterprises of the Central Black Earth zone, the Volga region, Northern Caucasus and Bashkortostan on slopes steep to 2-4° use plowing with making rolls height of 15-30 cm across the slope, which is carried out by lengthening the penultimate blade on the body plow.
On slopes up to 3.5-4° for water erosion control in Rostov oblast, furrow ploughing with breaker furrows of ППБ-0,6 type has proved to be a good solution. For intermittent furrowing, a key plough is also used, equipped with movable sections of plough bodies, each of which, rising and falling, creates intermittent furrows.
Creation of microlimans on the surface of cultivated soil contributes to retention of melt water. For their arrangement on slopes, bridge-maker is installed on a plough with extended mouldboards.
On ploughed and fallow fields in autumn it is applied hollowing with the help of six-section disc hollows-formers ЛОД-10 or special devices, which allow to create on the field about 13 thousand hollows, 130 cm long, 40-50 cm wide and 10-20 cm deep, with total capacity to 250-300 m3/ha of water. However, under conditions of periodic thaws and frosts, a stable snow cover is not formed, and ice lenses arise at the bottom of the wells, preventing the absorption of melt water. As a result, runoff not only does not decrease, but increases. In this regard, technical improvement of anti-erosion aggregates, which form rolls, holes and slits in one pass, absorption capacity of such holes increases due to location of holes above the slits, has received as an agrotechnical technique.
To reduce subsurface runoff a stepped multi-depth plowing is used, which is carried out across the slope by a plough, with even bodies exposed to normal depth and odd bodies exposed to a depth of 12-15 cm more. As a result the plow pan acquires a stepped configuration reducing subsurface runoff.
On highly sloping soils, where the efficiency of furrowing and hollowing is significantly reduced, slitting, chiseling and mole cutting are used. Slitting is carried out on winter crops, perennial grasses, bare fallow, natural hayfields, pastures and orchards, especially on early fallow lands. This method consists in making slits up to 40-60 cm deep, 3-5 cm wide and 100-400 cm wide with the help of slitters or other implements. The slits are usually cut in late autumn, when the soil is frozen, which ensures preservation of the slits until spring.
Mole-cutting is the creation of cavities-moles 6-8 cm in diameter at a distance of 0.7-1.4 m at a depth of 35-40 cm with the help of special devices. This method improves water permeability, moisture distribution along the soil profile, and removes excessive moisture in conditions of excessive moisture.
Methods of pre-sowing and post-sowing tillage
Sowing across the slope, at an angle or horizontally is used as soil protection measures for pre-sowing and post-sowing tillage. This method of sowing allows to reduce the velocity of water flow, increase the duration of water contact with the soil and moisture absorption.
Non-moldboard tillage
The system of tillage in the areas of wind erosion is based on the preservation of the limiting factor of yield – moisture. For this purpose, non-moldboard – flat-cutting and chisel tillage are used.
Non-moldboard tillage or plowing with ordinary plows with moldboard removed and stubble left at a depth of 27-32 cm across the slopes is good at preventing runoff and erosion. Soil-protective non-moldboard tillage allows to increase the reserves of moisture available for plants in one meter layer of soil by 20-40 mm and to increase the grain yield by 0,2-0,6 t/ha.
In cereal-fallow rotations with a short rotation, for example, 1 – bare fallow, 2-4 – crops, flat-cutting is used on all fields. Sometimes after perennial grasses in cereal-grass and cereal-row rotations, more often 2-3 years of use, the ordinary ploughs are used for cutting the layer with 23-25 cm of ordinary ploughs. In the presence of weak (Agropyron, Onobrychis) turf for greater conservation of moisture and prevention of wind erosion, plowing can be replaced by a preliminary discing with subsequent flat-cutting, chiseled cultivation or deep loosening.
Plowing of perennial grasses in all cases is carried out in strips. Width of cultivated and sown strips multiple of 50 m depends on the power of prevailing winds, steepness of slope and granulometric composition of soil.
In moist forest-steppe areas with 350-450 mm of precipitation with black earth soils for row crops depending on the type and density of soil, the use of organic fertilizers, weediness of the field can be used ordinary plowing to a depth of 23-25 cm.
In areas of wind erosion, non-moldboard tillage is mainly used.However, if necessary, for example, for the embedding of organic fertilizers and turf of perennial grasses, reclamation treatments of irrigated or saline soils, different types of mouldboard tillage are used.
Fertilizer application on eroded soils
Indirect erosion control measures include the application of organic, mineral fertilizers, micro– and bacterial fertilizers, liming and cultivation of siderats. Due to their effect on improving the development of aboveground and root mass, density of crops and a positive role in creating erosion-resistant soil structure, the protective effect of fertilizers and ameliorants is manifested.
The need of crops on eroded soils in nitrogen and phosphorus fertilizers is higher than on non-eroded soils. Therefore, fertilizer doses on medium eroded soils are increased by 20%, on highly eroded – by 50%. At the same time, measures to reduce runoff significantly increase the effectiveness of fertilizers.
On eroded soils of Bashkortostan yield of winter wheat from application of 20 tons of manure increased by 0.4 t/ha, 40 tons – by 0.5-0.6 t/ha.Complex application of manure and superphosphate increased the yield by 1.1 t/ha, against the control – 1.3 t/ha. According to the Research Institute of the Central Black Earth Strip named after V.V. Dokuchaev, the application of 10 t of manure and 60 kg of nitrogen fertilizers on eroded soils increased barley yields by 48%. V.V. Dokuchaev Research Institute, the application of 10 t of manure and 60 kg of nitrogen fertilizers on eroded soils increased barley yields by 48%.In Tatarstan the application of peat and manure compost and mineral fertilizers increased the yield of green mass of corn from 8.2 to 17.3 t/ha.
Eroded soils are characterized by low content of microelements, especially zinc, boron, molybdenum, bromine, cobalt, so the application of microfertilizers shows greater efficiency.
Of great importance is the use of green fertilizers as an organic fertilizer. For this purpose can be used: annual and perennial lupine, clover, alfalfa, fodder beans, white mustard, bittercane, rape, vetch, seradella and others.
Syderal crops may be cultivated as intermediate, post-mowing, stubble or fallow-seeded crops. Plowing green matter as fertilizer has the same effects as applying manure.
Doses of organic and mineral fertilizers for eroded soils, determine by the formula:
where F is the dose of manure and nitrogen fertilizers, t/ha; Fm is the dose of manure and nitrogen fertilizers on unwashed soil, t/ha; K is the reduction of humus in washed out soils, % of unwashed.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Soil-protective complex of measures
Soil-protective complex of measures is an integral part of farming system aimed at protection of soil from erosion and prevention of development and spreading of erosive processes.. It includes agro-forestry reclamation, agrotechnical, organizational, water management measures, application of soil-protective methods in crop rotation, soil tillage system, fertilizer system, etc.
The importance of soil-protective complex of measures increases with intensification of agriculture and increasing loads on soil. In conditions of Russia, where in each region water or wind erosion is observed to a greater or lesser degree, farming systems should take into account the system of soil protection.
An important condition for creating erosion-resistant agrolandscapes is a systematic approach, adaptability to local conditions, comprehensiveness, environmental sustainability, economic and technical feasibility, environmental and socio-economic expediency.
Development of a soil-protecting complex
Soil-protective complex of measures is developed for each soil-climatic zone taking into account local peculiarities, type and degree of erosion, natural ecological and erosion situation:
- the general condition of the land area (landscape) of the land, district, region, territory, republic in terms of exposure to erosion;
- nature of soil cover and potential erosion hazard;
- features of the terrain;
- vegetation cover, e.g. afforestation, availability of natural hayfields and pastures, sodding, structure of areas under crops;
- climate features;
- human activities, i.e. specialization, farming systems, tillage practices, fertilizer use, machinery, etc;
- economic, social and environmental consequences.
When developing a complex of measures to control soil erosion, one should be guided by the Methodological instructions “Anti-erosion organization of the territory of an agricultural enterprise” (Russian normative document).
In zones of water erosion manifestation soil protective measures are designed and implemented within the boundaries of water-collecting basins in the following sequence: from watershed to the foot of slope, from watershed line of gully and gully system to the mouth. In the zones of manifestation of wind erosion complex of measures covers the entire erosion area, including a group of agricultural farms or administrative districts. In zones of joint manifestation of water and wind erosion both requirements should be met.
The question of the necessity of using a particular erosion control measure should be decided on the basis of comprehensive consideration of conditions: climate, topography, soil cover features and economic opportunities of the farm. Cost-effectiveness of soil protection measures – achievement of the maximum efficiency of techniques and their complex with the minimum exclusion of valuable lands and the least expenditure of resources for their implementation.
Design of erosion control measures shall include:
- drafting of general schemes of the complex of anti-erosion measures for the republic, territory, region;
- drafting of erosion control schemes by soil-erosion zones, including interrelated agricultural farms and administrative districts;
- development of erosion control complexes for the enterprise;
- development of design and estimate documentation for the construction of hydrotechnical, water management constructions and the creation of protective plantations.
Development of a scheme of a complex of anti-erosion measures for the republic, territory, region includes soil-erosion zoning, selection of zones and areas similar in the nature of erosion processes and a set of planned soil protective measures. Types, volumes, terms of performance and cost of works on soil protection shall be determined.
Annual plans of erosion control measures shall be developed on the basis of the scheme. Each enterprise shall have a project and a long-term plan of soil protection measures and measures to improve the fertility of eroded lands. Specialists and managers of enterprises should organize control over implementation of these measures.
Project of complex of soil protective measures is prepared on the basis of: documentation of on-farm land management, soil and agronomic maps, maps of relief and steepness of slopes, data on amount and character of precipitation, data on the size of meltwater runoff, development of wind and water erosion.
The design takes into account:
- the influence of the degree of washout and dispersion of the topsoil on crop yields;
- possibility of using soil-protective, humus and symbiotic role of certain crops;
- the amount of time the soil is not occupied by plants or plant residues;
- peculiarities of each land plot;
- possibility of application of erosion control measures in specific conditions.
The design of erosion control measures is carried out in the following order:
- The relief, steepness, length, shape and exposition of slopes, climatic conditions (amount, distribution and character of precipitation, wind speed and direction, temperature regime) are studied. Water reserves of snow cover, intensity of melting and condition of soil by the period of snow melting are taken into account. The period of occurrence of erosion danger is determined. Data of soil conditions such as granulometric composition, texture, thickness of humus layer, soil density and moisture, degree of washing out and blowing out are analyzed.
- The erosion danger of crops in crop rotations is assessed. For this purpose coefficients of erosion danger of field crops determined by A.S. Stantsyavichyus for north-western regions of Non-Black Earth zone on sloping lands are used. The following crops are considered erosion hazardous: black fallow – 1,0, root crops – 0,8, corn for silage – 0,5, spring cereals – 0,5. Soil protection level includes: leguminous-cereal mixtures – 0.4, spring crops with undersowing of perennial grasses – 0.3, winter rye – 0.2, winter crops with undersowing of perennial grasses – 0.1, perennial grasses of the first year of use – 0.05, perennial grasses of the second year of use – 0.03, perennial grasses of the third year and more – 0.01.
- Methods of placement of crops on sloping lands or on soils at risk of wind erosion, such as striped, continuous, contour-striped, with creation of buffer strips, etc., are established. The composition and order of alternation of crops in crop rotations at their strip arrangement should ensure protection of soils during the whole erosion hazardous period.
- The system of fertilizers in crop rotation is built, taking into account soil-protection requirements.
- The anti-erosion methods of tillage for each crop are determined.
- Methods of sowing and methods of care of crops for each crop are determined.
- Soil tillage, sowing and harvesting aggregates and the direction of their movement are determined.
- Measures for accumulation and regulation of snowmelt are envisaged.
For a more detailed study, a field complex survey of the territory is carried out.
Classification of lands by erosion hazard
According to the Methodological Guidelines, all lands are divided into 4 groups, including 9 categories, of which 5 are suitable for cultivation:
1.Land suitable for intensive use in farming.
I category. Land not subject to erosion, located on watersheds and near-watershed slopes with a slope of up to 1° and a runoff line length of up to 200m. Potential intensity of soil washing out not more than 3 t/ha per year.
Category II. Land subject to slight erosion. Upper gentle areas of slopes with a slope up to 3° and runoff line length up to 300 m. Potential intensity of washout 3.1-10 t/ha per year.
Category III. Lands prone to erosion. Middle and partly lower parts of slopes with slope up to 5°. Length of runoff line is from 300 to 600 m. Potential washout of 10.1-20 t/ha per year.
2. Land limited suitable for tillage but unsuitable for cultivation of row crops.
IV category. Lands subject to severe erosion. Middle and partly lower parts of slopes with steepness up to 8°. Length of runoff line is from 800 to 1000m. Potential intensity of washout 20,1-40 t/ha per year.
V category. Lands very prone to erosion. Lower parts of slopes with steepness more than 8° adjacent to gully banks. Potential intensity of washout more than 40 t/ha/year.
3. Land unsuitable for cultivation.
VI category. Land of gullies, their upper parts adjoining arable lands, with steepness from 10 to 15°. Length of drain line is from 1000 to 1500 m. Grass vegetation is thinned and there are washouts. Amount of washout at plowing can reach 100-150 t/ha per year.
VII category. Lands of lower parts of gully slopes, 15-17° steepness. Length of runoff line is from 1500 to 2000 m. Potential intensity of washout at plowing can reach 150-200 t/ha and more.
4. Lands unsuitable for agricultural use.
Category VIII. Gully slopes rugged with frequent scour, steepness over 8-10°, located between ravines with depth over 10 m, distance between ravines up to 150-200 m. Narrow gullies of less than 200-250 m, with steep slopes of more than 17-20°, their bottoms are exposed to erosion.
Category IX. Gullies not subject to flattening, outcrops of chalk, gravel, stony talus, sands and others.
Depending on the degree of risk of wind erosion, a complex of anti-erosion measures may be built according to the following recommendations:
- Land not subject to wind erosion. No measures are taken.
- Land slightly exposed to the risk of wind erosion. Simple anti-erosion measures are used: conduct of tillage in optimal terms, use of fertilizers, snow retention, use of non-moldboard tillage and sowing with stubble remaining on the surface, strip planting of crops and fallows by 100-150-200 m wide strips perpendicular to wind direction, creation of a network of field-protection forest strips.
- The lands are moderately exposed to wind erosion. The measures applied to the previous category are supplemented by non-moldboard tillage and sowing with maximum preservation of stubble, in arid areas – use of strip seeded fallow and strip planting in combination with buffer strips of perennial grasses.
- Land highly exposed to wind erosion. The full set of available erosion control measures is used: introduction of soil-protective crop rotations with high specific weight of perennial grasses, non-moldboard tillage, sowing with maximum preservation of stubble, sowing of crops, fallows and buffer strips of perennial grasses in strips 50-100 m wide, perpendicular to wind direction, continuous grassing of wind-affected slopes, creation of thickened network of forest strips.
- Land very much exposed to wind erosion. Not suitable for permanent crop cultivation. Can be used for full grassing of hayfields and pastures with surface and radical improvement. In some cases can be allocated in soil-protective crop rotation with 1-2 fields of cereals and 3-5 fields of perennial grasses under the condition of protection by forest strips.
Effectiveness of a complex of erosion control measures
At Novosilsk zonal agromeliorative experimental station of Orel oblast, with the area of 700 ha of lands, experience in application of complex of measures against water erosion, including organizational-economic, hydraulic, forest-meliorative and agrotechnical measures, has been accumulated. Soil erosion was stopped on the whole area, cereal crops yield increased 3 times. The lands of this station are divided into categories depending on washout and slope. Field crop rotations were introduced on slopes with unwashed and slightly washed away soils, and soil-protecting ones on strongly washed away soils. Hollows and gullies are grassed and used for pastures with justified rational pasture rotation. The autumn tillage is carried out by mouldboard and non-moldboard ploughs in 27-30 cm across the slopes. Harrowing, cultivation and sowing are also carried out across the slope. Organic and mineral fertilizers are widely used.
In Stavropol Krai, much attention is paid to special soil-protective crop rotations on slopes, where more than half of the fields are allocated for perennial grasses. As a rule, row crops are excluded or occupy small areas. Soil-protective measures include tillage and sowing across the slope, strip planting, cutting rolls horizontally, tillage with stubble remaining, and grassing of gullies and ravines.
In the farm “Giant” in the Rostov region, with characteristic dust storms that recur every 2-3 years, and the duration of winter snowstorms is 10-12 days, and wind speed 15-20 m/s. To control erosion, field protective plantations, reasonable alternation of crops in crop rotations, and special agrotechnical measures are successfully used.
At the Pavlodar experimental station on soil erosion protection (Kazakhstan), a complex of anti-erosion measures, including soil-protective crop rotations with strip arrangement of crops, in which strips of annual crops and strip fallow alternate with strips of perennial alfalfa or Onobrychis in mixture with Agropyron. Width of strips is the same for sandy soils – 50 m, light loam – 100 m. Stripes are located across the prevailing winds. The flat-cutting tillage of the soil with stubble left on the surface is used. On fallow fields, mustard strips are grown for snow accumulation and protection against blowing. When harvesting cereals, high stubble is left and straw is scattered across the fields. Drought-tolerant crops and varieties are used in crop rotations, herbicides are widely used, and the number of mechanical treatments is minimized. Areas unsuitable for growing annual crops are grassed.
A scientifically sound complex of erosion control measures, adapted to local conditions, can significantly reduce or completely prevent the risk of soil erosion development.The experience of enterprises in Siberia, Altai, Trans-Urals, Volga region shows that even in severely dry years in the steppe regions of Siberia the application of soil protection measures allows to get 1.1-1.2 t/ha of grain, in years with sufficient moisture – up to 2 t/ha.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Soil erosion
Soil erosion is the destruction of soil by water and/or wind. The word “erosion” comes from the Latin “erosio,” which means erosion or destruction.
In the history of agriculture there are many facts of destruction and degradation of soils. According to various estimates, about 2 billion hectares of arable land have been destroyed by erosion in the last 200 years, which exceeds the currently cultivated area of about 1.5 billion hectares.
A distinction is made:
- depending on the factor of destructive impact:
- water erosion;
- wind erosion, or deflation;
- combined erosion which combines water and wind erosion.
- depending on the speed of the process:
- normal, or geological, or natural;
- accelerated, or destructive, or anthropogenic.
Irrigation erosion is possible in areas of artificial irrigation and mudflows in mountainous areas.
Normal erosion is characteristic of areas with natural vegetation cover, where soil losses can be restored in the course of soil formation. Accelerated erosion occurs when natural vegetation is removed, improper use of land is observed in areas with dissected relief, more often in the steppe and forest-steppe zones, where special anti-erosion measures are neglected.
The most dangerous type of water erosion is gully erosion, which leads to the formation of ravines with loss of area. Among wind erosion are dust storms, or black storms, which destroy crops and sweep away the top layer of soil in a few hours, capable of filling irrigation networks and reservoirs.
In the forest-steppe and often in the steppe zones of Russia, the simultaneous manifestation of water and wind erosion – combined erosion is possible. Combined erosion manifests itself in the following aftermath:
- runoff and washout of the soil in the spring period,
- desiccation,
- spraying, especially with repeated tillage,
- deflation (blowing out, scattering, carry-over) or severe spraying in dry years
- with repeated tillage,
- stormwater runoff in summer,
- severe washout and erosion of soil.
There may be cases when arable layer is almost completely washed away by water and carried away by wind. On heavily sprayed fields, wind erosion of the topsoil can be observed in a few hours after precipitation.
Distribution areas
The northern border of the wind erosion zone runs along the line Voronezh – Samara – Chelyabinsk – Petrozavodsk – Omsk – Novosibirsk and further in Eastern Siberia: Khakassia, Buryatia, Tuva, Chita region. Therefore, all arable lands and pastures located to the south apply soil protection measures against wind erosion. Regions with a high risk of wind erosion development: the Volga region, the North Caucasus, the Urals, Siberia. The total area of agricultural land at risk of wind erosion is more than 45 million hectares, of which 28.7 million hectares is arable land.
According to the data of land balance in the Russian Federation, there are 36.5 million hectares of agricultural land subject to water erosion, including 24.7 million hectares of arable land. Water erosion caused by melt and storm water is mainly manifested in the forest-steppe zone. Areas of Central Black Earth zone, Volga region, Central region, Northern Caucasus are most exposed to water erosion. Meltwater runoff here reaches 80-100 mm (l/m2).
In the Non-Black Earth zone, much of the agricultural land is located on sloping lands. According to the estimates of the Russian Research Institute of Farming and Soil Erosion Protection 34% of arable lands in this zone are situated on slopes less than 1 degree, from 2 to 3 degrees – 3%, from 3 to 5 degrees – 17%, from 5 to 7 degrees – 7%, more than 7 degrees – 3%. 38% of the arable land is eroded and 62% is in erosion hazardous condition.
It is known quite a lot of examples when the spreading of erosion took place on vast territories rather quickly and led to soil depletion and land destruction. Erosion is causing significant damage to land in Canada, China, India, Australia, most countries in Africa, Europe and Asia. For example, 300 years ago the southern boundary of the Sahara Desert was 400 km north of where it is today.
About 40 million hectares of arable land in the U.S. from erosion by the mid-50s was destroyed, 20 million hectares of which were withdrawn from use. At present, about 115 million hectares of arable land in the United States are completely destroyed or seriously damaged, and 313 million hectares are subject to varying degrees of erosion processes.
In Russia intensive soil erosion started in the second half of the 19th century. Plowing of new lands by destroying forests and herbaceous vegetation with low level of agrotechnics in conditions of plain relief led to rapid development of erosion, first of all in the Central Black Earth zone.
In 1846 in the Central Black Earth zone of Russia 41,2% of the territory was arable, 20 % – forest, 23,2% – virgin lands. By 1887 the area of arable land had grown to 69%, and the area of forests and virgin lands had fallen to 25.6%. In 1914, the share of arable land was already about 80%, the area of forests – 6-7%. Currently, in some regions the share of arable land reaches 90% and more.
According to Goskomzem (State Committee on Land Resources) on January 1, 1996 over 117 million ha of 210 million ha of agricultural land are considered erosion hazardous and exposed to water and wind erosion, 51 million ha of which are eroded, 84.8 million ha of arable land and 35.1 million ha of pastures, 28.7 million ha and 14.4 million ha respectively. Soil erosion control is the most important link in the system of agricultural production development measures.
Factors of erosion development
In constructing scientifically sound erosion control and prevention measures, it is important to understand the patterns and causes of the spread of erosion processes. The degree of manifestation of erosion depends on:
- climate,
- soil and vegetation cover,
- topography,
- geology,
- economic purpose of the land.
Climatic factors
Climatic factors of water erosion development, first of all, include atmospheric precipitation and regime of their fallout, especially heavy rainfalls, which are the most dangerous in the period of insufficient development or absence of vegetation on the soil surface.
In one downpour, depending on the intensity of rain and steepness of slope, from 1 hectare of arable land is washed away from 10 to 50 tons of soil. The whole arable layer and gully growth up to 30-50 m can be washed away.
Soil erosion from melt water runoff is widespread in the Non-Black Soil and Central Black Soil zones, in the Volga region and Western Siberia. Average annual water reserve of snow cover reaches 100 mm and more. When melting in spring, this mass of water drains from the fields in 7-10 days, destroying the soil up to the formation of ravines.
Erosion resistance
Erosion resistance of soils is a factor of erosion development, which depends on the physical-chemical, water-physical properties and granulometric composition of the soil: humus content, composition of the absorbed complex, friability of the composition, water permeability, watertight structure.
Relief
Soil washout increases directly proportional to the slope. Increase of soil slope from 2 to 4° leads to 1.8 times increase of soil washout, from 4 to 8° – 7.2 times. Slope length also influences on water erosion. According to data of A.D. Orlov, washout increases 2.9-3.7 times in case of doubling of runoff line from 50 to 100 m.
The shape and exposition of slopes have a significant influence on soil washout. For example, southern slopes are often more eroded than northern and northeastern ones. Contour tillage of soils is carried out on difficult slopes.
Vegetation cover
Vegetation cover can reduce or completely prevent the development of water and wind erosion. The stronger and more powerful the vegetation cover, the higher its anti-erosion properties. The vegetative mass protects the soil from the destructive power of raindrops, and the root systems bind the soil particles, preventing soil erosion and washout. The degree of protective properties of vegetation cover is expressed by the erosion hazard coefficient.
Perennial grasses have the best soil-protecting properties. Their developed vegetative mass and powerful root system protect the soil from erosion processes and enrich it with organic matter. Winter crops have good soil-protecting properties. Row crops and bare fallow practically do not protect the soil from erosion.
Table. Erosion hazard coefficients
| Bare fallow | |
| Row | |
| Spring cereals | |
| Winter cereals | |
| Perennial grasses |
Soil protection capacity of crops is determined by biological and agrotechnical peculiarities, as well as the rainfall regime. Thus, in areas where water erosion is caused by melt water, perennial grasses have the greatest anti-erosion value, while winter, spring and leguminous crops have good protective properties under runoff associated with summer showers.
Soil-protective role of field crops depends on the phase of plant development, which is conditioned by the state of aboveground vegetative mass and root system during erosion-dangerous periods. The more developed the green mass, fuller coverage of the soil surface, and more powerful the root system, the more reliable is the protection from erosion.
Soil protection capacity of cultivated crops is calculated by the weighted average value of projective coverage in erosion hazardous period according to the formula:
Pa/w = 100(P1S1 + P2S2 + P3S3 + … + PnSn),
where Pa/w – weighted average projective soil coverage by crop of the rotation, P1, P2, P3, Pn – projective soil coverage by each crop, S1, S2, S3, Sn – area occupied by each crop, % of total area of crop rotation or arable land.
Thus, average weighted projective soil coverage by crops by ten-days or months of the growing season, taking into account the precipitation regime and the phase of plant development are determined.
Geological factors
Geological factors of the territory determine the potential possibility and character of erosion. They include the stability of rocks, the specificity of their occurrence, and the manifestation of various exogenous and endogenous processes. For example, loess-like loams of Altai Priob’ye, on which the soil cover lies, are easily eroded and destroyed by water flows. Large gullies, ravines, depressions and canyons can be formed in a short period of time.
Granulometric composition, genesis, soil type, as well as humus content, composition, structure and water strength of soil are the factors determining the development of erosion processes.
Black earth and sod-podzolic loamy soils are more resistant to water and wind erosion.
The natural conditions for the development of wind erosion under improper land use include light granulometric composition, poor texture and low moisture content of the upper soil layer.
Table. Threshold wind speeds at 0-15 cm (by A.I. Baraev and E.F. Gossen)[1]Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. - Moscow: "Bylina", 2000. - 555 p.
Economic activity
Human economic activity determines the condition of the soil cover, fertility, and the susceptibility of cultivated land to erosion. Economic factors include the following:
- general organization of the territory: the placement of fields and the structure of cultivated areas, road network, forest strips, production facilities;
- applied methods of basic and pre-sowing tillage and cultivation technologies, such as mouldboarding or non-moldboard tillage along or across the slope, degree of soil compaction and spraying, care of crops and fallows;
- degree of application of preventive anti-erosion and soil protection measures, such as soil-protective crop rotations, sowing of perennial grasses, minimization of tillage, agro-forestry, hydraulic and other anti-erosion constructions;
- reclamation works: construction of reclamation systems, dams, ponds, reservoirs, road network, backfilling of ravines, quarries, etc.
Human activity can both improve and deteriorate the condition of the land area and landscape. Not taking into account the laws of nature and irrational use of land can lead to desolation of many areas, making them unsuitable for agriculture. For example, the burning of forests on the mountain slopes by Cuban planters has led to severe water erosion. Within a generation, heavy tropical downpours washed away the unprotected top fertile soil layer, leaving exposed rocks.
The causes of water erosion caused by human activity are destruction of vegetation on slopes, overgrazing, clear-cutting of forests and bushes, and soil tillage that does not correspond to the relief.
One of the main causes of wind erosion in the steppe areas caused by human activity is imperfect tillage technology: annual plowing with stubble embedding, use of disc-tillers and smooth rollers.
In O. Owen’s book “The Protection of Natural Resources”, there are examples of ancient civilizations in Asia, Africa and the Mediterranean of Europe, which used the most valuable land resources irrationally. The soils of these areas were at one time the basis of a flourishing agriculture. Gradually, however, barbaric attitudes toward land exploitation led to severe erosion, rendering them unusable and causing the mass migration and starvation of peoples of entire empires.
Many of the world’s deserts serve to illustrate how society, if developed spontaneously rather than directed consciously, leaves deserts behind.
On the contrary, relying on the laws of nature, farming, and understanding the factors of erosion processes, people can control these processes, preventing the development and spread of erosion and creating conditions for sustainable and productive farming.
Complex manifestation of erosion factors
The factors of erosion and deflation manifest themselves in some combination and interaction in a complex way. The influence of the complex of factors on the development of wind erosion can be traced in detail on the example of the Kulunda steppe of Altai Krai, according to A.N. Kashtanov.
| Natural conditions | Deflation Factors |
| Climate | Droughts recurring with a frequency of 2-3 years out of 5 years. Winds with speeds of more than 5 m/s during the period of absence of vegetation and the number of days 35-50. Abrupt change in daytime temperatures and night frosts |
| Relief | Gentle-sloping or flat, creating favorable aerodynamic conditions for wind. Presence of wind-impact elevations and corridors |
| Soil cover | Chestnut soils of light granulometric composition, containing insufficient amount of wind-resistant aggregates. Low moisture capacity, water retention capacity, cohesiveness. Separate partial state (dispersion) of arable layer |
| Vegetation cover | The amount of open cultivated land is 70-90%. Predominance of annual crops, sowing of perennial grasses is 5-8%. Absence of winter crops. Lack of vegetation cover for 8-9 months. Weak plant development, low projective cover. Thinned vegetation cover of natural lands. Forest cover of the territory is 1,5-2%. |
The complex impact of these factors can make these agricultural lands unusable in a short period of time.
The combined effect of water and wind erosion is most destructive after rapid spring snowmelt and meltwater runoff, accompanied by strong washout and erosion, as well as soil dehydration. After that, there is a long (1-2 months) period of drought, during which deflation occurs. The scheme of this process: snowmelt → meltwater runoff → soil washing out and erosion → desiccation, drainage of soil cover → soil spraying under the influence of tillage, moisture loss → deflation.
Mechanism of water erosion development
Erosion processes develop under the action of water, wind, and their mutual influence. The mechanism of water erosion development was studied by Sobolev, 1948; Bennett, 1958; Hudson, 1974; Zaslavsky, 1979; Kashtanov, 1974; and others.
Raindrops and water flow are considered as acting forces of water erosion.
In modern Russian and foreign practice, rainfall erosion index is used, an index that takes into account the kinetic energy of rainfall during the period of maximum intensity of rainfall. As a rule, the period is taken equal to 30 minutes. In this case, the erosion index of precipitation is calculated by the formula:
where I30 is the maximum intensity of rain in 30 min, mm/min or l/m2 per minute; E is the kinetic energy of rain.
When assessing the erosion hazard of rain on the average annual erosion index, it is important to consider the monthly distribution of the index values. Sometimes, when the annual erosion index of rainfall is small, the risk of erosion development is higher than when it is large.
Surface water runoff can cause surface and linear erosion.
Surface, or planar, erosion is a relatively uniform washout of soil over the entire surface. Little noticeable and therefore very dangerous, it is observed on fields located on slopes of different gradients, almost annually. Depending on conditions, from 5 to 25 tons of soil is washed away from 1 ha of arable land, in some regions up to 30-50 tons/ha. Over several years, the arable layer can be reduced by half or more, taking the fields out of use. Because of its invisibility, it can remain unnoticed by the specialists of the farming enterprise.
Linear, or gully, erosion is accompanied by soil erosion under the action of jet streams of water, leading to the formation of gullies. The width of jet stream erosion can reach 2-3 m, and the depth – to the plow pan. The washouts and scour holes subsequently turn into gullies. Gully erosion is widespread in the Central Black Earth zone and the Volga region. In some cases, the annual growth of gullies is more than 10 m, up to a maximum of 300 m per year.
As a result of surface and linear erosion, washed away soils of shortened profile are formed. Depending on the thickness of the washed away layer, weakly washed away, medium washed away, strongly washed away and very strongly washed away soils are distinguished.
Depending on the form of precipitation, two types of erosion are distinguished: from rainfall runoff and from meltwater runoff. Erosion from melt water runoff, as a rule, covers large territories, stormwater erosion – locally, on separate territories. Erosion hazard period from melt water runoff is 5-15 days in spring, when there is no vegetation, and from heavy rainfall – a few hours, during summer, when there is insufficient development of crops.
A classification of water erosion has been developed based on the type of surface runoff and the form of erosion manifestation.
Surface runoff can be caused by temporary water flows, such as irrigation or outflowing groundwater.
Surface runoff of water streams that cause erosion is divided into:
- meltwater;
- rainwater;
- irrigation water;
- rising groundwater;
- wastewater.
Forms of erosion:
- soil washout, which is subdivided into:
- weakly washed away soils (surface erosion);
- medium washed away soils;
- strongly washed away soils;
- soil erosion (linear erosion), which is subdivided into:
- scour;
- ravines;
- jet erosion, which, depending on its manifestation, is classified as surface erosion or linear erosion.
Meltwater runoff is determined by water reserves of snow cover and intensity of snowmelt. It amounts to 80-90 mm in the north of the Central Black Earth zone, 40-50 mm in the south, 30-60 mm in the Volga uplands and 90-100 mm in the Central region (Tula, Moscow and Ryazan regions).
Washing away of the soil is possible already at a steepness of 1.5-2°. The steeper the slope, the more intensive the soil is washed away. Intensity of washing away depends on slope exposure and soil type. Clayey and loamy soils with strongly spreading structure are more prone to washout than sandy loamy soils with good permeability.
Table. Soil washout depending on slope steepness (Belgorod region, typical loamy black earth, southern exposure, convex slope, tilled, according to I.D. Braude)
Irrigation erosion
Irrigation erosion is a type of water erosion, which appears under the influence of irrigation water runoff during furrow irrigation in conditions of complex topography. The intensity of irrigation erosion depends on the exposure, shape and steepness of the slope, the type of watershed and its area, and soil properties.
As a result of irrigation erosion up to 100-150 t/ha of soil may be lost annually, together with which up to 0.8-1 t of humus, 100-120 kg of nitrogen and 110-165 kg of phosphorus are taken away. On soils subject to irrigation erosion, crops grow and develop unevenly, and yields are reduced. Significant areas of irrigated lands in the Volga region and Central Asia (more than 1.5 million hectares) are subject to this type of erosion.
To prevent the development of irrigation erosion they use:
- cutting irrigation furrows on the lowest slope not deeper than 10-12 cm;
- when increasing the slope from 2 to 6°, the length of furrows is reduced from 150 to 100 m, irrigation by jet – from 0.1 to 0.05 l/s;
- in cotton crops on heavy soils the slitting of inter-row spacing is carried out;
- irrigation of slopes with light soils is carried out by sprinkling;
- doses of fertilizers on washed-out soils are increased by 25-40%;
- cotton-alfalfa crop rotations with three years of alfalfa are introduced, after which on medium- and highly washed away soils, green manure crops are placed or organic fertilizers are introduced in doses up to 30-40 t/ha.
Mechanism of wind erosion development
The mechanism of wind erosion development is a physical process of interaction of air flow with the soil surface. The works of Russian and foreign scientists are devoted to the study of this mechanism, which serve as a theoretical basis for the development of soil protection techniques against deflation. The soil aggregates of the size 0,1-0,5 mm which under the influence of a wind get rotary movement with frequency 200-1000 min-1 move on a surface most easily. Aggregates with diameter from 0,6 to 1 mm move by rolling, rubbing against each other, striking, destroying, thereby increasing the number of most erosion-active 0,1-0,5 mm particles.
Erosion-hazardous particles have a great destructive power, moving by leaps and bounds, they break larger clumps, damaging crops.
To move aggregates larger than 1 mm requires a wind speed of more than 11 m/s at a height of 0-15 cm.
Table. Wind speed at which soil aggregates begin to move
Analysis of the structural composition of aeolian (sediment) deposits and in dust traps during dust storms showed that the content in fine soil of particles smaller than 1 mm is 92-95%, larger than 1 mm – 5-8%.
Particles less than 1 mm in diameter are erosion hazardous, while particles larger than 1 mm are wind-resistant. Thus, soil resistance to deflation can be assessed by the lumpiness of the surface, i.e. the presence of windproof aggregates. When the number of soil clod-resistant aggregates is less than 50% of the air-dry soil, the risk of blowing out increases greatly, so this degree of lumpiness is considered critical, or erosion hazardous. The threshold of soil resistance to wind erosion in the absence of crop residues on the surface occurs at a lumpiness of 50-55%.
Table. Structural composition of sediment and fine grains from dust traps, % (according to Baraev and Gosen, 1980)
| Aeolian sediments | |||||||
| Fine grains from dust traps | |||||||
Wind erosion can appear in the form of dust (black) storms and under the influence of constant local daily winds, or local erosion. The latter occurs in the form of overhead erosion and surface erosion (along the ground). Overhead erosion consists in trapping soil particles and lifting them upward by swirling motion. Surface erosion is the rolling of soil particles over the surface or by gradients.
Heavy spraying of the top 5 cm layer of soil is often the result of excessive mechanical tillage and rubbing of soil particles by the undercarriage systems of machinery during field work.
Wind erosion can manifest itself in the form of dust storms, which destroy and carry away partially or completely the arable layer.
Dust storms are most common in Western Siberia, the North Caucasus, and the Volga region on light soils. Particularly severe storms were observed in 1892, 1928, 1960,1965, and 1969.
Wind and water erosion have different effects on agrophysical properties of soils. Wind erodes and transports top to 5-10 cm layers of soil. Water, on the one hand, dissolves and transports soil particles to deeper horizons and washes away upper layers, dissolves and carries away by washing deep into or washing away nutrients.
Soils in steppe areas subject to wind erosion are usually characterized by a deficit of phosphorus, whereas soils subject to water erosion are characterized by a deficit of nitrogen and other mobile nutrients. Losses of humus and mineral nutrients accumulate over time and depend on soil type and erosion severity.
Wind erosion can also occur during the winter. Strong winds blow away the snow cover, exposing and drying the soil. Together with snow, it is blown off the fields and forms earthen drifts elsewhere.
Mechanism of combined action of water and wind erosion
Combined erosion is most often observed in the North Caucasus, the Central Black Earth zone, the Volga region, the Trans-Urals, and Western and Eastern Siberia. The mechanism of joint action combines the processes and energy of water and wind erosion, as a consequence of which the effects are also common, characteristic of both water and wind erosion.
Combined erosion occurs when the following factors combine:
soil over-wetting – water runoff – washout;
washout – desiccation – spraying – blowing out.
In areas with stable and strong snow cover, erosion in spring and summer periods occurs according to the scheme: snowmelt – soil over-moistening – meltwater runoff – soil washing out and erosion – desiccation – spraying – deflation. In areas with little snowy winters, dry spring and wet summer period the process usually develops according to the scheme: drying and spraying – deflation – rainfall – runoff – washing out and erosion of soil.
In erosion-active years during 2-3 months of joint influence of water and wind erosion gully growth makes up to 30-50 m and more with subsequent blowing out of arable layer up to 3-5 cm.
Combined effect of water and wind erosion leads to destruction of soil cover: reduction of humus layer thickness, reduction of organic and mineral nutrients content, deterioration of structure, porosity, water permeability, moisture capacity, water retention capacity, water and nutrient regimes.
Classification of soil erodibility
The degree of soil erodibility is determined by the reduction in the depth of the humus horizon, the loss of humus and nutrients. Depending on the washout and blowing out, a distinction is made:
- slightly eroded,
- moderately eroded,
- heavily eroded,
- very strongly eroded soils.
There are several classifications based on the degree of soil erodibility and on the reduction of humus content in the upper layer. The latter is proposed by M.N. Zaslavsky:
- weakly washed away – the content of humus in the upper layer compared to unwashed soil by 10-20% less;
- moderately washed away – humus content is 20-50% lower;
- heavily washed away – humus content is 50% or more less;
- very strongly washed away – humus content is 75% or more less.
S.S. Sobolev proposed a classification depending on the degree of washed away humus horizon. According to this classification we distinguish:
- slightly washed away – up to half of the humus horizon washed away;
- moderately washed away – more than half of the humus horizon washed away;
- heavily washed away – the transitional or illuvial horizon is partially washed away;
- very strongly washed away – the humus and transitional or illuvial horizons are completely washed away; the parent rock is plowed away.
These classifications require refinement because they are not related to the arable layer.
For soils subjected to wind erosion A.F. Rodomakin proposed the following classification of erodibility:
- slightly deflated – up to 20% of the humus horizon is blown out;
- moderately deflated – 20-40% of humus horizon has been blown out;
- severely deflated – 40-60% blown out;
- severely deflated – more than 60% were blown out.
When determining the degree of erodibility, the soil profile of the same type unaffected by erosion, i.e. full-profile soils, is taken as a reference.
In modern agriculture, a number of anti-erosion techniques have been developed and applied to protect the soil from erosion and prevent its development and spreading.
The main soil-protecting techniques:
- Measures to protect soils from water erosion:
- grassing of heavily eroded slopes;
- soil-protective crop rotations;
- contour-tillage;
- forest reclamation;
- land reclamation facilities such as dams, water regulation swale systems, and diversion ditches;
- strip rolling and snow blanketing, and use of snow retaining shields.
- Measures to protect soils from wind erosion:
- cereal-fallow, cereal-row crop rotations with a short rotation;
- buffer strips of perennial grasses;
- strip planting of bare fallows and row crops;
- strip cropping;
- flat-cutting tillage;
- sowing of cereals by stubble seeders;
- forest amelioration;
- regular irrigation.
- Measures to protect soils from combined erosion:
- soil and water conservation land management of the territory;
- grassing of heavily eroded slopes;
- cereal-grass, cereal-fallow and cereal-row crop rotations;
- strip planting of bare fallows, row crops and perennial grasses;
- flat-cutting across the slopes after cereals;
- trenching, for example, after perennial grasses and corn, ploughed soil and fallows;
- slitting of perennial grass crops;
- mulching the soil with chopped straw;
- forest reclamation;
- hydrotechnical constructions;
- agrohydromeliorative soil-protective complex in the watershed.
The leading role in erosion control is given to the systems of tillage of soils subject to water erosion and tillage of soils subject to wind erosion.
Soil-protective complex of measures – a set of science-based measures aimed at preventing and avoiding the development and spread of water and wind erosion, applied taking into account the adopted farming system.
An important condition for the creation of erosion resistant agricultural landscapes is a systematic approach, adaptability to local conditions, comprehensiveness, environmental sustainability, economic and technical feasibility, environmental and socio-economic expediency.
Due to the accumulated scientific and experimental data, for most regions of Russia and different conditions, soil-protecting complexes have been developed and successfully used, allowing to obtain high yields with a significant reduction or complete prevention of erosion processes.
Damage caused by soil erosion
Soil erosion in the absence of measures to prevent its development and spread, can cause enormous economic and environmental damage, removing land from the fund of agricultural land.
The main components of the damage caused by soil erosion are:
- reduction of the potential fertility of soils,
- deterioration of chemical and agrophysical properties,
- decline in biological activity,
- reduction of yields and deterioration of product quality,
- reduction in the effectiveness of chemicalization measures.
As far back as 100 years ago V.V. Dokuchaev noted, the decrease in the fertility of black soil, the growth of gullies, droughts and famine are a direct consequence of improper land use. He was the first to propose a scientifically sound set of measures to prevent erosion events.
Currently, erosion processes in varying degrees are observed in almost all regions of Russia. In the absence of soil-protective measures on erosion-prone lands, the total annual loss of soil from washing away can reach, according to M.N. Zaslavsky’s calculations, 7 billion tons. Losses of humus layer during dust storms are from 1 to 10 cm, while it takes more than 100 years to create 1 cm of humus layer in natural conditions.
According to V.A. Belyaev, in Russia about 5.4 million tons of nitrogen, 1.8 million tons of phosphorus and 36 million tons of potassium are lost annually from fields and pastures as a result of washout. According to the calculations of Russian Academy of Agricultural Sciences academician V.D. Pannikov, loss of 1 mm layer of southern black earth from 1 ha area causes loss of 76 kg of nitrogen, 24 kg of phosphorus, 80 kg of potassium, while for production of 1 ton of grain it is required on average 66 kg of nitrogen, 20 kg of phosphorus and 26 kg of potassium.
If we take the content in the arable layer of an average of 0.2% nitrogen, 0.2% phosphorus and 2% potassium, then the annual washout of 4 billion tons of soil, leads to a loss of about 100 million tons of nutrients.
According to U.S. researchers, as a result of erosion, 20 times more nutrients are lost than are taken out with the crop.
In a number of zones, the rate of erosion of arable soils is 5-15 times higher than soil formation. According to F.K. Shakirov, 0.6 t/ha of soil is formed per year, while washing out is 3-7 t/ha, reaching in some years 50 t/ha. Soil losses in orchards and vineyards can reach 30 t/ha and more, in bare fallows – 60-150 t/ha and more.
Table. Humus reserves in the 0-50 cm layer of different degrees of washing out, t/ha
| Dark gray forest | ||||
| Common black earth | ||||
| Southern black earth | ||||
| Chestnut | ||||
| Brown forest | ||||
Erosion processes lead to deterioration of agronomic properties of the soil: soil compaction, reduction of moisture retention capacity, deterioration of soil regimes, loss of clay and silt particles, which negatively affects the structure.
According to the data of the Soil Institute named after V.V. Dokuchaev, the reserves of humus of the best Russian black earth (chernozems) in the world for the last 70 years after the plowing decreased by almost 250 t/ha, the water-holding capacity decreased by 500-600 t/ha, and the potential productivity – by 0,5-0,6 t/ha of dry grain per year. At the enterprise “Kashirskiy”, Moscow region, in the potato field without anti-erosion tillage in conditions of severe erosion the soil washout for the season was 196 m3/ha, loss of humus from 1 ha – 8.7 t, nitrogen – 44.3 kg, phosphorus – 41.7 kg and potassium – 65.2 kg.
Together with the runoff of meltwater and rainwater, which amounts to 400 to 700 m3/ha, up to 50-100 t/ha of soil and 100-150 kg/ha of nutrients are washed away annually; in areas of wind erosion the same amount is blown away, respectively.
At Smolensk experimental station from sod-podzolic light loamy soil at a steepness of 4-6 ° and length up to 300 m annually washed away from 1 ha up to 5.7 tons of fine-grained soil containing 127 kg of humus, 98 kg of potassium, 24 kg of nitrogen and 10 kg of phosphorus.
Soil erosion will change the qualitative composition of humus, shifting the ratio of humic acids and fulvic acids towards the latter.
Decrease of humus content, available nutrients and deterioration of physical properties of eroded soils leads to decrease of biological activity and phytosanitary state.
Table. Microbiological activity of eroded black earth
| Unwashed | ||
| Weakly washed out | ||
| Moderate washed out | ||
| Highly washed out |
Characteristic agrophytocenosis, significantly different from plain lands, develops on eroded sloping lands. Weediness and root rot infestation increase on eroded soils.
Due to deterioration of physical properties of eroded soils, the ability to assimilate melt and rainwater decreases. As a result, runoff coefficient may increase up to 0.8-0.9, and considerable part of precipitation drains from slopes. In addition, water losses from evaporation increase. According to calculations, annual slope runoff results in the loss of up to 60-80 billion m3 of water, causing soil drought, which is supplemented by deflation.
In general, from the negative impact of erosion on the complex of agrophysical properties of soil, the yield of agricultural crops decreases. It is conventionally considered that on weakly washed away soils the crop yield decreases by 10-30%, on medium washed away – by 30-50%, on strongly washed away – by 50-70%. Washing out and erosion of pasture soils leads to reduction of hay yields by 2-3 times and more.
Table. Crop yields on soils with different degrees of erodibility, % of unwashed soil
| Winter wheat | |||
| Winter rye | |||
| Spring wheat | |||
| Barley | |||
| Oats | |||
| Corn | |||
| Peas, vetch | |||
| Sugar beets, potatoes | |||
| Sunflower | |||
| Vetch-oat mixture | |||
| Sudanese grass | |||
| Perennial grasses |
More precisely, the decline in yields depends on the degree of washout, weather
conditions, the genetic type of soil, the composition of the crops being cultivated, farming practices, and other factors. Crops can respond differently to soil erosion.
On a national scale, 1/3-1/4 of gross crop production is lost annually from eroded agricultural lands.
Damage caused by water and wind erosion also affects micro- and nano-relief, silting of rivers and lakes, reduction of productivity of forage lands, etc.
As a result of erosion processes, the productivity and sustainability of agriculture and the economic returns of agricultural production are reduced.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Yagodin B.A., Zhukov Y.P., Kobzarenko V.I. Agrochemistry/Under ed. B.A. Yagodin. – M.: Kolos, 2002. – 584 p.: ill.
Problems of energy conservation and soil compaction
Tillage is the most energy-intensive and expensive technological method of farming. Currently, it accounts for up to 40% of energy and 25% of labor costs of the total amount of field work. To estimate, if we recalculate all tillage techniques for plowing, 6,000 tons of soil is moved on each hectare annually.
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction (Русский Español)
Navigation
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction (Русский Español)
For example, when growing potatoes and sugar beets the fuel consumption for tillage operations is 18% of the total consumption, when growing winter wheat, corn and sunflowers – 41 and 43%.
The most energy-consuming tillage is plowing, which accounts for more than 50% of total fuel consumption. At the same time, fuel consumption and energy intensity of the technological process increase with the use of wheeled tractors. According to the data of zonal research stations, the use of wheel tractors for plowing such as К-700 increases fuel consumption by 22% compared with tractors such as ДТ-75, and the total energy consumption by 35%, respectively 604 and 812 MJ/ha.
Table. Consumption of diesel fuel for growing field crops, kg/ha (M.M. Severnev, 1992)[1]Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. - M.: Publishing house "Kolos", 2000. - 551 p.
| Winter wheat | ||||
| Corn | ||||
| Sunflower | ||||
| Sugar beet | ||||
| Potatoes |
Measures to reduce energy costs
In the system of agro-technical measures to reduce energy costs are important:
- increasing soil fertility,
- increasing the content of humus,
- creation of deep arable layer with a good state of cultivation,
- improvement of all soil properties,
- saturation of crop rotations with deep penetrating root systems,
- applying increased doses of organic and mineral fertilizers,
- application of grasses and sideration,
- application of chemical reclamation,
- integrated plant protection system,
- conducting all field work in optimal agrotechnical terms.
That is the creation of a arable layer with a good state of cultivation, helps to reduce energy costs for its tillage and reduces the negative impact of soil compaction. For example, fuel consumption when plowing compacted soil in optimal conditions is 12-14 kg/ha, whereas when plowing compacted soil heavily littered with couch grass (Elytrigia repens) – about 20-25 kg/ha. On soils with a good state of cultivation it is possible to use technologies of minimum tillage.
The solution of problems in the direction of energy saving and ecologization are the following organizational and technological measures:
- development and application of economical and environmentally friendly techniques and technologies of tillage with maximum effective material, energy and labor performance with minimum negative impact on soil fertility. The methods should take into account the soil and climatic conditions, biological and technological features of crops, the availability of accompanying technical resources in the farm and the features of the agricultural landscape;
- application of highly productive large-capacity and combined machines and units with the maximum combination of technological operations;
- wide implementation of minimum tillage methods;
- use of tractors with a lower specific pressure of the undercarriage systems;
- correct selection of working tools of tillage machines and implements;
- use of a special symmetric frame with a set of quick-changing working tools as a carrier machine to make up units that perform several technological operations in one pass;
- elimination of residual deformations in subsoil layers by deep chiseling, slitting and other methods;
- use of tires in the running systems of machinery of larger size, arched and wide profile tires, twin wheels, half-track and pneumatic tracks;
- rational combination of tractors and tillage machines and implements;
- regulation and optimization of technological parameters and speed modes of operation of tillage implements;
- performance of tillage methods on the scientific-based movement routing basis. Reducing the number of passes of machinery on the field, especially heavy wheeled, filling machines with fuel, fertilizers, herbicides, seeds at the margin of fields.
Research and practice show that in crop rotations it is rational to apply different methods combining surface, shallow and deep; mouldboard and non-moldboard tillage taking into account soil-climatic conditions, phytosanitary state of soil, crops of crop rotation and agrolandscape features.
Perspective tasks of farming development in the field of energy saving and reduction of negative impact of heavy machinery on the soil are:
- development of soil-protective running systems of agricultural machinery, for example, new types of caterpillar and pneumatic-tracked mover, flexible – ultra-low pressure tires, working tools of tillage machines and implements, non-tractor machine systems (bridge or cable farming), combined machines and implements, large-capacity units with less metal intensity and acceptable pressure on the soil;
- creation of a new generation of soil-protecting complex of machines in accordance with modern requirements and directions of development of agro-landscape farming.
Excessive soil compaction
Harm caused by excessive soil compaction
The use of heavy tillage machines and transport vehicles under the existing multi-operational technology of soil and crop care leads to excessive soil compaction under the influence of running systems.
Soil compaction leads to:
- reduction of water permeability and overwatering of the upper layer, which increases water erosion;
- formation of surface crust when compacted soil dries out;
- deterioration of gas exchange;
- poor quality of seed embedding and reduced field germination, for example, barley germination is reduced by 27-30%, and winter wheat germination – by 23.4%;
- a decrease in the number of beneficial microorganisms;
- slowing down microbiological and redox processes, thus reducing the availability of nutrients to plants;
- 24-30% reduction in fertilizer efficiency.
Losses of grain yield per hectare due to compaction amount to 0.82-1.24 t, and overuse of diesel fuel – 2.5-3.5 kg. The most tangible losses are noted in wet areas.
One passage of tractor consolidates the soil to the depth of 45 cm, at multiple passes, especially in tractor К-700 – to 50-60 cm. The consequence of compaction is steadily manifested for several years, especially in the subsoil layers.
When growing crops machine-tractor units make 5-15 passes on the field, compacting tillage and subsoil layers. During the period of pre-sowing tillage and sowing only machine-tractor systems cover up to 80% of the field area, and potato, sugar beet and other row crops planting during spring period are subjected to 3-5 times influence of aggregates only. The total area of their traces during the whole complex of field works reaches 100-200% of the field area.
According to the data of the Department of Agriculture of the Moscow Agricultural Academy, at seeding with tractors ДТ-75 direct and indirect deformation is exposed 21.6% of the field area, tractors Т-150К – 29,4%, tractors К-700 in aggregation with three seeders – 39%. Density of sod-podzolic soil on the trail of wheeled tractors increases by 0,1-0,3 g/cm3, thus reaching 1,35-1,55 g/cm3 that is significantly higher than optimal density of soil for field crops. Crop yields in the grain-row crop rotation of vetch-oat mixture – winter wheat – barley – potatoes decreased for 10 years by an average of 6-22% due to the compaction effect of tractors. The greatest decrease was observed from wheeled tractors Т-150К, К-700.
Table. Weight of tractors and specific pressure of running systems on the soil[2]Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. - M.: Publishing house "Kolos", 2000. - 551 p.
| МТЗ-52 | |||
| ДТ-75 | |||
| Т-150К | |||
| К-700 | |||
According to the data of the Moscow Agricultural Academy named after K.A. Timiryazev, under autumn plowing at the depth of 20-22 cm sod-podzol medium-loamy soil of the Non-Black Earth zone at the depth of 20-80 cm the density for 10 years of using tractors Т-150К and К-700 increased by 0.1-0.15 g/cm3, reaching the value 1.38-1.62 g/cm3.
According to long-term experiments of the North-Caucasus branch of the All-Russian Research Institute of Agricultural Mechanization, on black earths the resistivity of the soil at plowing on 20-22 cm on the tracks of light wheeled and tracked tractors is 12-15% higher than beyond the tracks, and on the tracks of tractors Т-150К and К-701 – by 44%. Quality of soil crumbling worsened: out of tracks degree of crumbling of layer was 87%, and on tracks of tractors Т-150К – 83%, К-701 – 56%. Compaction effect of these tractors extends to a depth of 40-60 cm, maximum – to 1 m.
Permissible specific pressure for the majority of soils is 0,4-0,5 kg/cm2, maximum – 1,0-1,5 kg/cm2. However, power-packed wheeled tractors have an indicator up to 3-4 kg/cm2 and more. According to the level of compaction impact on the soil Russian tractors can be placed in the following order: ДT-75 < МТЗ-52, МTЗ-100 < МTЗ-82 < Т-150К, К-700 < К-701.
Excessive soil compaction leads to deterioration of agrophysical, biological and agrochemical properties. At a constant depth of cultivated layer a plow pan is formed – excessively compacted layer, negatively influencing water, air and heat regimes of soil.
The strongest reconsolidation takes place at increased soil moisture. For this reason the optimum condition for tillage is the state of physical ripeness, which is in the range of moisture for sod-podzolic soils – 12-21%, gray forest – 15-23%, black earth – 15-24%. For all types of soils, the recommended moisture content for processing is not higher than 65-70% of the smallest moisture capacity. The permissible pressure on the wet soil at 60% of the smallest moisture capacity for the early spring harrowing is 0.3-0.4 kg/cm2, during the pre-sowing tillage – 0.5-0.6 kg/cm2, the main tillage – not more than 1-1.5 kg/cm2.
Loss of yield of field crops in the link of grain-row crop rotation vine-oat mixture – winter wheat – barley – potatoes on average for two rotations was 6-22% depending on the compaction action of tractors. The greatest decrease was noted when using Т-150К and К-700 tractors.
According to calculations of the Soil Institute named after V.V.Dokuchaev, the total losses of cereal crops from excessive compaction of soils in Russia reach 13-15 million tons, sugar beet – more than 2 million tons, corn grain – about 0.5 million tons.
Table. Effect of tractors' running systems on the yield of field crops in the conditions of Non-Black Earth zone, 100 kg/ha (N.S. Matyuk, average for 10 years, 1993)[3]Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. - M.: Publishing house "Kolos", 2000. - 551 p.
| No compaction, control | |||||
| МТЗ-80 | |||||
| ДТ-75 (Т-150) | |||||
| Т-150К | |||||
| К-700 |
The tillage of compacted soils is associated with an increase in energy costs. According to calculations, fuel consumption in the tillage of compacted soils increases sharply, for example, when plowing more than 1 million tons per year.
The main reason for the decrease in crop yields with soil compaction is the deterioration of conditions for the formation of a powerful root system and its active functioning. According to the data of the Minnesota Agricultural Experiment Station (USA), increasing the density of loamy soil from 1.16 to 1.38 g/cm2 leads to a 6.2-fold decrease in pea root length and 1.9-fold decrease in mass. Soil compaction causes the formation of a surface root system, which affects the mineral nutrition of plants, which deteriorates by 36-42%, even with sufficient moisture supply.
Measures to reduce soil compaction
The basis of the system of measures to limit the level of impact of heavy machinery on the soil are preventive measures aimed at reducing the number of passes of machinery and decompaction of the soil in its processing, the introduction of increased doses of organic fertilizers and enrichment of organic matter, liming or application of gypsum, improving the structure.
To prevent excessive compaction, the soil is tilled when it reaches physical ripeness. On all types of soils, tillage is carried out at a moisture content of not more than 60-70% of full moisture capacity.
According to the recommendations of the Russian Academy of Agricultural Sciences the permissible load limits for wet (60% of the smallest moisture capacity) sod-podzolic loamy soil during early spring harrowing are 0,3-0,4 kgf/cm2, during pre-sowing tillage – 0,5-0,6, during the main tillage – 1,0-1,25 kgf/cm2. For typical heavy loamy black earth the pressure on the soil during the main tillage should not exceed 0.8-1.0 kgf/cm2, during sowing and pre-sowing tillage – 0.4-0.6 kgf/cm2.
To reduce excessive soil compaction during early spring works, such as harrowing, sowing and pre-sowing cultivation, it is necessary to use tracked tractors or tractors with twin tires, pneumatic-tracks and, if possible, avoid using wheeled tractors such as Т-150К, К-701.
Especially great damage to the undercarriage of tractors cause crops of winter cereals and grasses during the early spring fertilization with nitrogen fertilizer. Heavy fertilizer spreaders compact the soil, so it is advisable to use aircraft or tractors with pneumatic-tracks for fertilizing.
When using wheeled tractors, they are aggregated so that the tractor track coincides with the track of the trailed implement. Tractor and trailed implement tracks are additionally loosened during pre-sowing work, and the depth along the track is increased by 3-4 cm. Filling aggregates with seeds, fertilizers, herbicides or fuel is carried out outside the field or on specially designated roads.
Optimization of the routes of agricultural machinery on the field is an important preventive measure to prevent excessive compaction of the soil. For this purpose, permanent routes (tracks) for movement of aggregates during sowing and plant care are established. Movement of machinery by permanent routes using the same marks allows reducing the area of soil compaction by 1.7-2.7 times in comparison with uncontrolled movement.
When tilled crops are taken care of, repeated movement of machinery should be carried out on the same track on which the planting was carried out.Failure to comply with this rule leads to plant damage by the working elements of the cultivator, because the width of the docking rows is not always maintained during sowing.
Minimization of tillage involves reducing the number of passes of machinery on the field, which is achieved by combining several technological operations and techniques and performing them in one work process. This approach allows reducing the number of passes over the field by 2-3 times.
Reducing soil compaction is achieved by replacing or reducing the number of deep tillage by surface and shallow tillage at the expense of using large-capacity aggregates on weakly weeded fields. For example, in the conditions of the steppe zone the autumn plowing for early spring cereals is replaced by shallow tillage with the use of large-capacity units, for example, КПШ-9, КПШ-5, КПШ-11.
Reduction of soil compaction by mechanical tillage is achieved by different-depth tillage in the crop rotation; a combination of mouldboard and non-moldboard tillage, flat-cutting, disc tillage, chisel tillage, etc. Such systems allow reducing the load on the soil and the area of compaction by 30-40%.
An effective method of reducing compaction of subsoil horizons is periodic, carried out once every 3-4 years, chiseling to a depth of 30-40 cm. Deep loosening destroys the plow pan, loosens compacted subsoil layer, and improves water and air permeability. For this purpose they use chisel deep loosening tillers ПЧ-2,5, ПЧ-4,5, ploughs-loosening ПРПВ-5-50, subsurface (flat-cut) deep tillers, tools for non-moldboard tillage such as paraplau, ploughs with notched bodies.
The highest efficiency of deep loosening of subsoil layers is achieved when cultivating row crops: corn, potatoes, sugar beets and others, as well as winter crops. The yield of row crops thus increases by 15-20%.
Methods of deep loosening are also carried out in the system of contour meliorative farming. On soils at risk of water erosion, deep loosening across the slope contributes to the transfer of water flow across the surface into the intra-soil flow, increasing water reserves and reducing soil washout.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Quality of field work
Quality of field work is the degree of compliance of quality parameters and timing of the actual performance of individual techniques with the requirements of standards or agrotechnical requirements. The quality of field work determines the yield of crops.
Quality of fieldwork depends on the technical condition of tillage and seeding units, proper adjustment, quality of previous tillage, soil conditions, timing of work and other conditions.
Violation of agrotechnical requirements for tillage leads to:
- deterioration of growth and development conditions of cultivated plants;
- lower yields;
- reducing the effectiveness of fertilizers and chemical plant protection products,
- reduction in the effectiveness of land reclamation,
- the possibility of the development of soil erosion,
- reduction of soil fertility.
As a consequence, there should be organized a permanent control over the quality of fieldwork, and in particular over the quality of performance of certain techniques of tillage.
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork (Русский Español)
- Problems of energy conservation and soil compaction
Navigation
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork (Русский Español)
- Problems of energy conservation and soil compaction
The quality of performance of a separate technique of tillage, sowing and others is determined by a set of indicators, which characterize the degree of suitability of the soil for optimal plant growth and performance of subsequent technological operations.
Evaluation can be done on a three- or five-point system: excellent, good, satisfactory, poor and very poor. Each technique is evaluated separately and the total score determines the quality of field work.
In production conditions the work is evaluated as good, if it is performed within the prescribed period of time in compliance with all agro-technical requirements. Satisfactory is the work performed on time, in compliance with the basic agronomic requirements, but some quality indicators may be slightly out of the allowable deviations, without having a significant impact on the yield.
Poor is the work performed with gross violations of deadlines or agrotechnical rules, resulting in a significant reduction in yields. In this case, the work is rejected and redone.
Assessment of the quality of the work can be carried out during their implementation, which allows you to identify and eliminate deficiencies in advance.
Evaluation of tillage quality
Discing
The main indicators for assessing the quality of discing include:
- time of work performance,
- the depth of loosening and its uniformity,
- degree of undercutting of weeds and cutting of perennial rhizomes of weeds,
- ridging of the soil,
- crumbling of the cultivated layer,
- absence of gaps and untilled strips.
In addition, the observance of straightness of movement, the depth of the breakdown furrow at the junction of the middle batteries, which should not be higher than the set depth of discing, is taken into account.
Timeliness of discing significantly affects the effectiveness of this technique. It is carried out immediately after harvesting cereals, not later than 1-2 days, in order not to allow the soil to dry out. Allowable deviation of loosening depth from the specified one is not more than 10%. The loosening depth is measured at the beginning of the machine’s work and in the course of performance. It is recommended to make at least 25 measurements on the area equal to the shift task of the machine, and calculate the average depth of loosening. The depth is determined with a ruler or metal rod with graduations as the distance from the surface of the uncultivated soil to the bottom of the furrow.
When measuring the depth of the cultivated field, it is necessary to reduce the obtained average value by an elevation coefficient of 10-15%. The elevation coefficient is the ratio of the average depth of the cultivated disced layer to the average depth of discing.
The degree of cutting of weeds is determined by counting the number of uncut plants on a square of 1 m2. Counting platforms are set along the diagonal of the field at the rate of one platform per 10 hectares of the field area.
The presence of gaps and untilled strips is determined visually during inspection of the field.
Plowing
Quality of plowing depends on the condition of the field at the time of plowing, size, configuration, soil moisture, technical condition of the machine and other conditions. Before plowing, the field must be free of straw, stones, coarse plant residues, and if necessary, the field must be leveled. The best quality of loosening and crumbling is achieved when tilling the soil in the state of physical ripeness; tilling dry soil leads to strong clumping and requires large energy costs.
Soils with different technological properties must be cultivated with different plough bodies. For plowing of cohesive sodded soils ploughs with helical bodies or frontal ploughs, which are equipped with helical working surfaces, are used. All types of plowing old plowed lands, with the exception of plowing the fallow land and steam, filling organic fertilizers, processed by plows with cylindroidal plow bodies with skimmers. In areas with insufficient moisture and soils subjected to wind erosion, plows with no-till bodies are used.
On fields with a thickness of fertile stand less than 20 cm plowing is carried out to a depth equal to the thickness of fertile stand, and the subsoil layer is simultaneously processed by ploughs to break the plow footing and the gradual increase in the thickness of fertile stand.
In production environments the quality of plowing is evaluated at the beginning of work and in the course of work.
The main indicators of the quality of plowing:
- plowing time;
- depth;
- uniformity;
- degree of crumbling of the soil;
- clumpiness;
- ridging;
- quality of piled ridge and breakage furrow;
- straightness of plowing;
- the degree of embedding of crop residues, fertilizers, weeds;
- absence of untilled strips.
Table. Agrotechnical requirements for plowing
| Deviation of average plowing depth from the specified depth, % | |
| Uniformity of plowing depth, % | |
| Soil crumbling (proportion of clumps larger than 5 cm in diameter), % | |
| Piled ridge height, cm | |
| Plowing depth under the piled ridge | |
| Embedding plant residues, weeds, fertilizers | |
| Plowing straightness (deviation from straightness per 100 m of run), cm | |
| The presence of raw strips, wedges and other errors |
Timeliness of plowing is determined by comparing the set agronomic term with the actual one. Thus, in the central regions of the Non-Black Soil zone plowing for winter cereals is carried out immediately after harvesting the preceding crop within 5 days, no later than 2-3 weeks before sowing. Deviation from the established agrotechnical term leads to soil drying, excessive clumping, and field weeding.
A plow equipped with interchangeable bodies with helical mouldboards should turn the layer by 140…180° at a plowing depth of 25 cm. Front and linear plows must provide a full turn of the layer by 180°.
Allowable deviation of plowing depth from the set – no more than 10%, should be uniform. An exception is made for the first two passes of the machine in the piled corral. According to other recommendations, deviations on flat areas are allowed not more than 15%, on uneven areas – not more than 10%. Micro-relief of the field surface is considered uneven if deviations exceed 15 cm. The depth of plowing is measured with a furrow gauge or ruler by measuring the distance from the surface of uncultivated soil to the bottom of the furrow. For evaluation 25 measurements on several passes of the plough along the diagonal of the field are carried out. The deviation of the actual plough working width from the constructive one should not be more than ±10%.
Breakout furrows and pile ridges should be straight and barely noticeable. Deviation from straightness should not exceed ±10 cm per 100 m of run. Depth of plowing under piled ridge – not less than half of the specified. Breakout furrows are plowed after the end of plowing.
Crumbling of the soil is defined as the ratio of the mass of clods smaller than 5 cm to the total mass of the soil sample, expressed as a percentage. The size of selected sample is 40x30x30 cm. Quality of layer crumbling is judged by clumpiness (C), i.e. the share of clumps more than 5 cm in diameter (100-C). The crumbling of the layer when plowing old arable soils with general purpose plows should be at least 75% (the content of fractions up to 5 cm in size).
The clumpiness is determined by a frame with an area of 1 m2, divided into squares of 1 cm2. Perform 8-10 overlaps along the diagonal of the field. The clumps more than 5 cm in diameter falling in the frame are measured in length and width and their area is determined. The clumpiness is estimated as the ratio of the total area of the clumps to the area of the frame as a percentage. Clumpiness, occupied by clumps larger than 10 cm, is allowed no more than 15% of the arable area.
The cohesion and ridging of plowing characterize the uniformity of the height of all ridges and the surface of the plowed field without depressions and elevations, the absence of staggering in individual passes of the machine. It is determined by a profiler or by a 10-meter long measuring cord, which is laid across the ridges so that it repeats the surface of the field. The ratio of the extension of the cord to its projection shows the ridgeiness coefficient. Ridgeiness when plowing in the fall in conditions of moisture and on sloping lands has a positive value. When plowing in dry areas, for winter crops and main plowing, on the contrary, ridges are flattened. Ridge height should not exceed 5 cm for plows with cylindrical bodies, 10 cm for screw bodies and 4 cm for front and linear plows.
During moldboard plowing all weeds, stubble and crop residues, fertilizers, turf must be plowed. At plowing depth of 22-30 cm, plant mass should be incorporated to the depth of 10-15 cm with traditional plows and to the depth of 12-15 cm with front and linear plows. Depth of planting is determined by cutting the soil 40 cm wide (or the width of the plow) across the ridges to the depth of plowing.
Shallow plowing should ensure that 40-50% of stubble and crop residues are retained on the surface of the field. It is not allowed to crumble the soil into particles smaller than 1 mm.
One of the walls of the cut is made plumb, by which the upper and lower boundaries of the ploughed turf or plant residues are determined. According to the obtained data, a profile of a cross section with indication of the location of embedded turf is built.
In production conditions, the quality of embedded plant residues is determined visually by evaluating the amount of un-embedded stubble, turf per 100 m2 or 1 ha, which should not be more than 5.
The depth of plowing of field edges and headlands must correspond to the depth of plowing of the main area. Skipping between adjacent machine passes, unplowed wedges, plowing along the slope, except for overwatered lands are not allowed.
Flat-cutting
The quality of flat-cutting is evaluated according to the following indicators:
- term,
- working depth,
- uniformity,
- degree of soil crumbling,
- keeping of stubble on the surface of the field,
- adherence to joint overlaps in adjacent machine passes,
- ridging of the surface,
- straightness of tillage.
Table. Agrotechnical requirements for flat-cutting of the soil
| Deviation of the average depth of tillage from the set depth, % | ||
| Soil crumbling (fraction of clumps 3-5 cm in diameter at shallow tillage and 3-10 cm at deep tillage), % | ||
| Stubble retention rate (for one pass of the flat cutter), % | ||
| Height of ridges formed by ripper tines, cm | ||
| Width of furrows formed by ripper tines, cm | ||
| Trimming weeds | ||
| Overlap of adjacent unit passes, cm | ||
Timeliness of work, selection of implements and depth of flat-cutting are determined taking into account zonal features, soil type and moisture, biological characteristics of the crop, erosion risk, organizational and production conditions.
Loosening the soil is carried out in optimal periods: shallow – by flat-cut cultivators, such as КПШ-9, КПШ-11 at the depth of 8-16 cm and deep – by flat-cut deep tillers, such as КПГ-2-150, КПГ-250, ПГ-3-100 at 25-27 cm. The proportion of clods characterizing the degree of loosening of 3-5 cm for shallow and 3-10 cm for deep tillage should be the predominant part in the cultivated layer at the optimum moisture content of the soil.
Tillage depth should correspond to the specified one and be uniform. The permissible deviation of the average working depth from the specified one must not exceed ±1-2 cm for shallow tillage, and not more than ±2-3 cm for deep tillage. The working depth is determined across the entire working width of the machine with a metal rod with graduations. Measurements are taken not nearer than 30 cm from the track of the flat-cut unit. For objective evaluation 25-30 measurements along the field diagonal, on the area equal to the shift task, as a rule, 10 hectares are carried out.
The degree of stubble preservation on the surface during shallow tillage must be 85-90%, during deep tillage – at least 80-85%. To account for intact stubble on the surface of the soil are plotted area length of 10 m and a width equal to the width of the unit, on which measured the width of all the furrows left by each working tool plow. All measurements are summed up and the width of the tracks of the flat-cut unit is defined, expressing it as a percentage of the total length (10 m).
For example, on a 10 m long plot the total width of the damaged stubble strips is 1.5 m, then the degree of stubble conservation is equal to:
Roots of weeds during flat-cutting should be cut at the depth of the working bodies stroke, and the cultivated surface should be leveled. Ridges at the junction of ripper tines should be no higher than 5 cm, and the width of furrows in the places of tine legs passes – no more than 15 cm.
Gaps between adjacent machine passes, as well as gaps and unprocessed strips, wedges are not allowed. Turning strips are also processed to the specified depth.
Quality evaluation of pre-sowing tillage
The soil prepared for sowing (planting) must meet the following requirements: be fine lumpy, well loosened to the depth of sowing seeds, have compacted seed bed, weed vegetation is completely absent.
The clumpiness, i.e. the share of clods 3 cm in diameter and more must not be more than 15-20% in humid areas and 10% in arid ones. Clod sizes larger than 10 cm2 in the sowing layer are not allowed.
Quality of pre-sowing soil preparation is usually evaluated as a whole, rather than individual techniques, immediately before sowing.
Quality indicators of seedbed preparation include:
- timing of processing,
- tillage depth,
- uniformity of tillage,
- clumpiness,
- crumbling of the soil,
- degree of weed cutting,
- absence of uncultivated turning strips, wedges.
Table. Agrotechnical requirements for pre-sowing tillage
| Deviation of the average machining depth from the set depth, % | |
| Uniformity of soil tillage by depth, % | |
| Clumpiness (fraction of clumps larger than 3 cm in diameter), % | |
| Ridge height, cm | |
| Soil surface | |
| Trimming weeds | |
| The presence of raw strips, wedges and other errors |
Pre-sowing tillage is carried out before sowing or on the day of sowing.
An important indicator of pre-sowing tillage is thorough loosening of the soil to the depth of seeding and leveling of the surface. For this purpose, pre-sowing cultivation across or at an angle to the direction of plowing is used. Repeated tillage is carried out across the previous for better crumbling and leveling, on sloping lands – across the slope or along the horizontal relief.
The depth of loosened layer is determined with a metal ruler or a rod with graduations. For objective estimation carry out 25-30 measurements along the field diagonal and calculate the average value. The uniformity of the depth is determined by the deviation of the average processing depth from the specified one or by calculating the coefficient of field leveling.
Clumpiness and ridging are evaluated in the same way as for plowing.
The degree of weed undercutting is determined by overlapping a 1 m2 frame along the diagonal of the field and counting the uncut weeds. 10-15 counts are made per area, uncut plants are not allowed.
After finishing tillage of the field, cultivate turning strips, edges of fields. Untilled areas, ridges, depressions are not allowed.
The surface of the field cultivated by anti-erosion system must be windproof with at least 60% of the crop residues retained.
Evaluating the quality of sowing
Quality indicators of sowing (planting) include:
- sowing time,
- rates of seeding,
- established sowing depth,
- spacing of joints between rows,
- straightness of rows,
- absence of unseeded places.
Table. Agrotechnical requirements for sowing
| Deviation of the average sowing depth from the specified one, % | for small-seeded crops and grasses ±5 |
| Uniformity of seed embedment depth, % | |
| Seed rate deviation from the specified, % | |
| Deviation of the width of docked row spacing, cm | on adjacent aggregates ±4 |
| Row straightness (deviation from straightness per 100 m of run), cm |
Sowing (planting) should be carried out at the optimum time for the crop, taking into account its biological characteristics. Early crops are sown at the soil temperature of 4-6 ° C at the depth of the seed, late crops – 10-12 ° C.
Sowing should be carried out evenly with the set seeding rate. Deviations from the specified seeding rate should be no more than 4%. Uniformity of sowing of seeds by each seeding unit is determined by the number of seeds sown, for example, for a certain number of rotations of the seeder wheel. The seeds must be evenly distributed in the row at a given depth in a compacted bed and covered with loose soil. The deviation of the average sowing depth for cereals should be not more than ±1 cm, for fine seeds – not more than ±0,05 cm. Seeds on the surface are not allowed.
The sowing depth is determined by opening 2-3 rows from the front and rear coulters of seed drills, not following the tractor’s trail. To do this, first level the surface and measure the distance from the soil surface to the sown seeds. For an objective assessment at least 20 measurements are carried out along the diagonal of the field and several passes of the seeder.
For more accurate determination of the sowing depth use a cylinder with notches every 10 mm, in which the flaps are inserted. The cylinder is dipped into the row deeper than the seeds are sown, taken out and dissected by the sliders in 10 mm layers of soil. The seeds are separated from the soil on sieves and are counted according to their depth.
Straightness of the rows during sowing is estimated visually or by measuring the distance from the row to the straight line. The deviation should be no more than ± 10 cm per 100 m of the race, that is, the row must fit into a rectangle of 100×0,2 m.
Permissible deviation of docking row spacing at adjacent seed drills should not be more than ±2 cm, and the width of docking row spacing in two adjacent aggregate passes should not deviate from the specified width of the row spacing more than ±5 cm.
Turning strips, must be sown with the same seeding rate as in the whole field. Unseeded and double-seeded places are not allowed.
Evaluating the quality of crop care work
The quality of inter-row cultivation is evaluated according to the following indicators:
- tillage time,
- depth,
- uniformity,
- degree of crumbling of the soil,
- degree of weed cutting,
- absence of damage to crops.
The soil in the inter-row area must be tilled to depth, not allowing damage to the root system of the crop, with the observance of the protective zone in the rows.
The soil in the cultivated zone should be loosened, fine lumpy, leveled, except for crops requiring hilling. All weeds in the area of the cultivator working tools passage must be trimmed. Mineral fertilizers applied as top dressing – shall be embedded in the soil to a specified depth.
When hilling, wet soil must be covered to the stems of the plant. Damage to cultivated plants during the performance of tillage is not allowed. The quality control of care measures shall be carried out both at the beginning of work and during its implementation.
Productivity
The productivity of arable and other machines is the amount of work of a given quality done by them in the time interval T. Productivity is divided into theoretical (calculated) and actual productivity.
Theoretical productivity W is calculated by the formula:
W = 0.1BvT,
where B – design width of machine (plough), m; v – theoretical speed of machine, km/h.
Actual performance is always less than theoretical because of deviations of working width B, the actual speed vp and net working time Tp from the calculated values.
The working width of the machine may differ from the design one due to incorrect connection of machines to the tractor, erroneous adjustment of working tools, inaccurate machine operation, overlapping of the working width of individual machines included in the machine, poor technical condition and defects of the machines. The working speed of the machine differs from the theoretical one due to slipping of the undercarriage and poor technical condition of the tractor. Time during which the unit directly performs useful work (plowing, harrowing, etc.) differs from the calculated one, because part of the working time is spent on transfers, turns, stops for regulation, repair, cleaning and filling machines and on other organizational activities.
Therefore, the actual productivity is determined by taking into account the correction factor K by the formula
Wf = 0,1BvTK,
where K = BpvpTp / (BvT)
The organization of the units seek to ensure that the actual performance sought to the theoretical. To do this, they maximize the use of the design width of the working width, operate at higher speeds and optimally realize the time of the shift, also organize two- and three-shift units, especially in busy periods. Timely measures for maintenance of machines, compliance with the frequency of cleaning operations, lubrication, checking the condition of individual assemblies, working bodies, transmissions and their preventive adjustments are also of great importance.
To improve the maintenance of machines, group work of arable units is used.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Agricultural and Reclamation Machines. Klenin N.I., Sakun V.A. – M.: Kolos, 1994. – 751 p.: ill. – (Textbook and textbooks for higher education institutions).
Agricultural machinery. Khalansky V.M., Gorbachiev I.V. – Moscow: KolosS, 2004. – 624 p.: ill. – (Textbook and textbooks for higher education institutions).
Treatment of reclaimed land
Ameliorated land includes irrigated and drained soils, as well as soils of radical and surface improvement of hayfields, meadows and pastures. Treatment of reclaimed land has a number of features and is determined by crop rotation, weed infestation, methods of reclamation, level of fertility.
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land (Русский Español)
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction
Navigation
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land (Русский Español)
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction
Tillage of irrigated land
Irrigation water has a multifaceted effect on soil properties, biological and chemical processes, organic matter decomposition and fertility reproduction. Irrigation water carries soil colloids, soluble calcium and magnesium salts into the subsoil layers, which leads to destruction of soil structure, formation of soil crust and compaction of the arable layer.
Under the influence of water the structure of arable layer changes, total and non-capillary porosity decreases, aeration conditions change. According to All-Russian Research Institute of Irrigated Agriculture, the total porosity of irrigated black earth decreases by 8-10% compared with non-irrigated lands.
Change of soil structure is caused by compaction of arable and subsoil layers, due to which their water permeability decreases, there is an overwatering of the upper layer and large losses of moisture by evaporation, especially in the first days after irrigation.
Irrigation has negative aspects, which should be taken into account when building the system of tillage of irrigated land. These include secondary salinization and waterlogging, occurrence of water erosion and environmental pollution of water bodies by fertilizers and pesticides.
Characteristic features of soil tillage in irrigated crop rotations:
- soil compaction and deterioration of agrophysical and biological properties determines the need for more and deeper main tillage in the crop rotation in order to maintain a loose texture and optimal structure of the arable layer.
- Rational and economical use of water in irrigation is possible with its uniform distribution over the irrigated area. In this regard, the task of treatment includes the preparation of the field for the appropriate method of irrigation, such as leveling the surface of the field, construction of temporary irrigators.
- In irrigated crop rotations bare fallows are not used, so the irrigated land can be characterized by increased weed infestation. Irrigation water promotes the spread of weed seeds. Under irrigated conditions the species and quantitative composition of weeds changes, as a consequence of which the system of irrigated soil tillage should include a system of effective protection of plants from weeds, diseases and pests.
Tillage improves the air regime, increases its biogenicity, promotes activation of redox processes and, consequently, the nutrient regime, prevents and eliminates secondary salinization, waterlogging of irrigated lands, prevents the development of water erosion.
Tillage during irrigation includes:
- leveling and preparation of the field for irrigation,
- tillage system for spring and winter crops,
- tillage for intermediate crops.
Field leveling and preparation
For uniform distribution of irrigation water and soil moistening the surface is leveled and the necessary slope is given. Areas of water stagnation and over-watering in depressions should be excluded, which is important for the simultaneous onset of physical ripeness for cultivation and sowing. The leveling also prevents secondary salinization and waterlogging of irrigated land, the development of water erosion. The leveled surface of the field allows to automate the process of irrigation, to increase the productivity of tilling and sprinkler units, and to improve the quality of field works.
The main leveling is carried out at arrangement of irrigated lands according to the project. Irrigation by flooding method on rice fields (cards) requires horizontal leveling with small not more than 0,002 slope. Irrigation by furrows and strips apply leveling under sloping surface with big slope of fields.
Repair leveling is carried out on the areas with heavily deformed surface due to subsidence, irrigation, soil erosion or movement of heavy machines and aggregates.
Bulldozers and graders are used for preliminary leveling of elevations and backfilling of depressions. Final leveling of pre-ploughed soil surface is carried out by long-base levelers П-5, ПА-3, Д-719. The surface is leveled in two perpendicular directions without bumps and rolls, making 2-4 passes of the unit on one track.
For early crops the soil is leveled in autumn after harvesting crops, for winter crops – in summer after harvesting fallow crops.
Operational leveling of irrigated field surface is carried out annually when preparing it for irrigation or after plowing before sowing crops. Operational leveling eliminates slumped furrows, piled ridges, gaps and other irregularities. For its implementation with simultaneous loosening and mulching use mouldboard levellers such as ВПШ-15, ВП-8А, ВПН-5,6 and others with units moving at an angle to the direction of plowing.
Autumn tillage of irrigated land
The choice of autumn tillage methods under irrigation depends on the degree of soil moisture, weed infestation of fields, irrigation methods used, type of irrigation (water-charge, pre-tillage, etc.). If the soil is optimally moistened for crumbling and with a long post-harvest period, autumn tillage is carried out according to the type of half-fallow. Fields weeded by root-shoot weeds are disced twice: the first discing is done at a depth of 6-8 cm during the harvesting of cereals, the second – at 10-12 cm with mass emergence of weeds. With secondary growth of weeds perform plowing with ploughs with skimmers and harrowing. If the field is weeded with annual weeds carry out one discing to a shallower depth.
If the soil dries out after harvesting the crop, watering is carried out beforehand. Soil moistening promotes germination of weed seeds, improves crumbling and quality of processing.
For pre-tillage irrigation an irrigation network left after tilled crops is used; discing is not carried out in this case. If there is no irrigation network, it is created, and the soil after harvesting crops is previously disced.
On the fields, where it is planned to carry out water charging irrigation, simultaneously with plowing make irrigation furrows, slits or strips with the distance of 70-140 cm using re-equipped plows. For this purpose the mouldboard at the second body of 4-hulled plough is removed, thus during ploughing a furrow is formed. When the mouldboard of the same hull is lengthened, a ridge forming a strip equal to width of plough’s capture is formed. More qualitative cutting of furrows is carried out by a furrow-cutter, which is attached to the plough frame. The direction of plowing should coincide with the direction of irrigation. Plowing and cutting of irrigation furrows is located along the slope. At the transverse scheme of temporary irrigation system location the output furrows are cut at a distance of 300-400 m from each other at a field slope of 0.008.
If moisture in the soil is sufficient for high-quality plowing after harvesting of forecrop, watering is carried out after autumn tillage. For this purpose simultaneously with plowing make furrows or strips for irrigation. If it is necessary to level the field, simultaneously with plowing carry out harrowing, additional leveling in the places of split furrows and ridges, and then cut deep irrigation furrows.
After irrigation, when the soil dries out, carry out equalizing harrowing across the field, then along or diagonally. If weeds grow after equalizing harrowing, cultivate or discing to eliminate them.
Heavy soils with poor permeability in the system of autumn tillage or immediately before irrigation are additionally subjected to slitting by 40-50 cm. After irrigation the temporary irrigation network is levelled when the ridges dry up.
Deepening the arable layer of irrigated land
Significant soil compaction during irrigation leads to the need to increase the thickness of the arable layer to 32-35 cm, for which deep plowing, non-moldboard loosening or other methods are used. A deep arable layer with good permeability allows a more rational use of irrigation water and increases the efficiency of fertilizers.
Deep plowing with embedding of organic and mineral fertilizers prevents overwatering of soil, contributes to the rapid saturation of the soil profile with water to a depth of 50-70 cm, reduces moisture loss by evaporation and weediness, improves aeration and nutrition conditions for plants, in general, leads to increased yields. Therefore, in irrigated crop rotations the thickness of the topsoil is increased on black earth to 32-35 cm, light chestnut soils – to 25-27 cm. For sugar beets and vegetable crops in black earth soils plowing is carried out to a depth of 30-32 cm, for corn – to 25-27 cm, for cereals – 20-22 cm. The use of chisel implements and non-moldboard plow-ridgers allows increasing the depth of loosening up to 35 cm and more.
Methods of deepening depend on biological features of crops, soil type, compaction and irrigation norms. Thus, on heavy black earth at high irrigation rates, the frequency of deep plowing in crop rotations is 2-3 years, on light soils at low irrigation rates – 4-5 years.
Pre-sowing and post-sowing tillage under irrigated conditions
The soil before sowing should be sufficiently loose and level for quality seeding and vegetative irrigation.
Harrowing or shallow levelling is carried out for late sowing crops in early spring at the onset of physical ripeness. Loosening the top layer prevents moisture loss due to evaporation and salt transport to the surface, especially on saline soils.
On fields for later sowing crops, as a rule, two cultivations with harrowing are carried out. The first one – to a depth of 10-12 cm, the second – to the depth of sowing of the crop. The best quality of loosening and leveling of the surface is achieved by moving the unit across the plowing direction or at an angle.
Cultivation with harrowing is used instead of harrowing for early sowing crops, especially on heavy soils. If the surface is ridged, it is additionally leveled by combined units such as ВПН-5,6, ВП-8А.
At repeated sowing of crops in conditions of irrigation pre-sowing water charging irrigation is carried out, which can be carried out before the plowing by the preserved irrigation network. Plowing is carried out at the onset of physical ripeness to a depth of 22-25 cm with levelling the surface and preparing the field for sowing. However, more often irrigation is carried out after plowing, so simultaneously with processing the field is prepared for irrigation. After irrigation, when the soil reaches physical ripeness, the irrigators are closed, harrowing, pre-sowing cultivation and seeding with rolling the soil is carried out.
Loosening at 16-18 cm before or after early spring harrowing is carried out in the system of pre-sowing tillage with strong compaction of soil, for example, in the fields that received autumn watering.
When preparing the field for vegetative irrigation by strips the depth of pre-sowing cultivation for cereals is increased by 3-4 cm, due to the fact that part of the top layer goes to the formation of rollers, forming irrigation strips. Sowing without making irrigation strips is carried out across the slope of the field.
When caring for crops under irrigation, the main tasks are the elimination of soil crust, maintaining the surface in a loose condition, weed control. When caring for crops under irrigation, the main tasks are the elimination of soil crust, maintaining the surface in a loose condition, weed control. To do this before or after the emergence of seedlings, harrowing is carried out with light tooth harrows, reticulated harrows or rotary hoes. To reduce damage to plants, harrowing on sprouts carried out in the afternoon when the plants are weakened by turgor.
Alfalfa first year crops are harrowed after mowing with tooth or needle harrows; crops of previous years are loosened with cultivators with chisel or spring harrows when heavily weeded.
Loosening of row-spacing of row crops after irrigation is carried out at the onset of physical ripeness of the soil. The depth of the first loosening is increased in comparison with non-irrigated fields, to eliminate greater compaction of the irrigated soil.
To carry out vegetative irrigation in row crops simultaneously with inter-row cultivation the cutting of irrigation, withdrawal furrows and temporary irrigators is carried out. The number of inter-row loosening is determined by weed infestation, number of irrigations, soil compaction and weather conditions.
Tillage of drained lands
Reasons and tasks of land drainage
Large areas of drained lands up to 3.5 million hectares are located in the North-Western, Central and other regions, where precipitation prevails over evaporation and wetting coefficient is higher than unity.
Soil over-wetting can be short-term or long-term. Permanent over-wetting is caused by close groundwater occurrence, especially on the fields placed in the depressions of relief or flood plains of rivers. Temporary over-wetting is caused by surface water from atmospheric precipitation on soils with poor permeability or on fields with a low slope.
In conditions of over-wetting, when soil moisture during vegetation period makes more than 70% of full moisture capacity, soils with different degrees of gleying are formed. Excess moisture, lack of oxygen leads to a slowdown of redox processes and the formation of oxidized forms of iron and manganese, toxic to plants. As a result, soils are impoverished in available forms of nutrients.
Over-wetted soils thaw more slowly in the spring; they are tilled and sown later, which leads to lower crop yields.
Wet soils have most of their pores filled with water, which increases anaerobic processes. Optimal aeration porosity of arable layer for cereals is 20-30%, for potatoes and root crops – 25-40%, for grasses – 15-20% with soil moisture not exceeding 70% of field moisture capacity.
Tasks of drainage reclamation and system of drained lands tillage:
- Enhancement of surface runoff and diversion of excess moisture from root layer to improve air regime and activation of biological processes, for which narrow-band, ridging, ridge plowing, soil furrowing, etc. are used.
- Redistribution of subsurface runoff or provision of water accumulation in subsoil horizons achieved by deep plowing, tiered tillage, non-moldboard chisel loosening, mole cutting and other methods.
The choice of tillage system for drained lands is determined by the method of drainage, thickness of humus layer, granulometric composition, field slope, biological features of crops, weed infestation of fields.
The system of drained land tillage
On drained by closed drainage sod-podzolic, medium loam and clayey gley soils with poor permeability, i.e. with filtration coefficient less than 0.3 m/day the system of meliorative different-deep tillage in crop rotation is applied. It consists in deep plowing at 28-30 cm with a plough with notched mouldboards or two-tier plowing for row crops, winter crops or in seeded fallows. Such tillage in crop rotation allows to increase potato yield by 2 t/ha, green mass of corn by 2.6 t/ha.
Plowing depth for spring cereal crops, flax, annual grasses is up to 20-22 cm. When sowing perennial grasses for cover crops, the depth of plowing is increased to 23-25 cm or replace plowing by chisel loosening, which is especially important on gley soils. When perennial grasses are used for two years, as a rule, the soil is strongly compacted, which leads to deterioration of water permeability and complicates the work of drainage. Therefore, after perennial grasses, plowing for spring crops is carried out at greater depth, for example, for oats – two-tier plowing at 23-25 cm.
On light loamy and sandy loam sod-podzolic poorly gleyed soils with good permeability (filtration coefficient over 0.3 m/day) instead of tier tillage for row crops is carried out chisel loosening at 28-30 cm, for winter crops – at 20-22 cm.
Application of herbicides on light soils with a good state of cultivation, which are drained by closed potter’s drainage, allows to minimize the main tillage for winter rye and spring cereals. Under the predecessors of these crops perform plowing or chisel loosening. Replacing plowing with polydisc tilling to a depth of 10-12 cm, you can get the same yield of winter rye as when it is sown after annual legume-grass mixtures. The average yield for five years was 3.67-3.68 t/ha.
Table. Yield of winter rye at different methods of main tillage, t/ha
| Plowing at 20-22 cm (control) | |||||
| Polydisc tilling at 10-12 cm | |||||
| + to control |
On heavy soils deep reclamation tillage in the rotation alternate in a year, on light soils – in 2-3 years. It is most expedient to carry out them in the system of autumn tillage or after early harvesting of fallow-occupying crops. If fields are weedy, before deep tillage discing is carried out taking into account the species composition of weeds.
On heavy soils with poor permeability and fields with low slope the method of narrow-fence plowing is used additionally, which consists in splitting the field into narrow paddocks 12-22 m wide and plowed in pile. The width of paddocks is determined depending on slope, water permeability and tillage depth. On clayey and loamy soils with a slope of 0.02-0.05, the width of the paddocks is 10-12 m on the fields with a slope of 0.05-0.08 – to 15-22 m.
On fields with a slope of less than 0.01, paddocks are ploughed in the direction of the natural slope, with a higher slope – at an angle to it to prevent washing away. In order to avoid steep turns of the machine, two paddocks are ploughed simultaneously, e.g. the second and fourth, then the first and third. After plowing, drainage furrows with a distance of 50-100 m, which are connected to the drainage canals, are cut across the ploughed furrows. For better drainage of water they are made parallel to the direction of the slope.
In order to avoid soil displacement, the position of piling ridge and break furrow is shifted every year during plowing, while maintaining the width of paddocks.
To divert water of separate closed depressions in the fields, furrowing is carried out. This method is especially effective for planting winter crops and perennial grasses, because it prevents their soaking. Furrows are cut by furrow cutter or hiller from the place of water stagnation to drainage furrows. The depth of furrows is 16-22 cm. For winter crops, furrows are cut simultaneously with sowing.
Because of the large losses of arable area furrowing is not economically justified, so it is carried out selectively.
Deepening of the arable layer and improvement of the state of cultivation of drained lands
Deepening of the arable layer is an effective method of improving the state of cultivation of drained lands. Humus sod-podzolic and sod soils with a slight degree of gleying deepen the arable layer to 30-32 cm by gradual inclusion of 3-5 cm of soil in tillage, with the simultaneous application of organic, mineral fertilizers and lime. On heavy soils with strong gleying, plowing with plows with notched mouldboards, two-tier plowing or non-moldboard loosening are carried out.
The depth of plowing of boggy peat soils is determined by the thickness of the peat horizon. If the thickness of the peat layer is up to 30 cm, plowing is carried out to the depth of its occurrence with preliminary milling of the upper layer. Soils with gley horizon are additionally loosened with non-moldboard chisel tools at 38-40 cm, not removing it to the surface because of its strong toxicity to plants. Subsequent inclusion of 3-5 cm of mineral soil in the underlying layers, enhances mineralization of peat and consolidation of humus substances. This method of deepening activates the activity of actinomycetes, cellulose-decomposing and ammonifying bacteria and fungi, contributing to improvement of nutrient regime and the state of cultivation of bog soils.
On heavy soils with poor permeability deep continuous or strip loosening to the depth of 50-60 cm is applied, which promotes water filtration and optimizes air and water regimes of dried lands. It is carried out in perpendicular to drainage lines or at an angle for better outflow of excess water from the arable layer. The distance between loosening strips on heavy soils is 2.5-5 m, on light soils – up to 7.5 m.
Deep loosening is carried out after autumn plowing when soil moisture is less than 70% of full moisture capacity. For improvement of permeability of subsoil layers it is combined with mole cutting using ripper-mole cutters of РК-1,2, РК-1,2M type.
In order not to reduce the yield in the first year, annual grasses are sown after deepening of arable layer. As the state of soil cultivation improves, more fertility-demanding crops such as winter rye, potatoes, flax, etc. are sown.
Pre-sowing tillage of drained lands
Pre-sowing tillage on drained lands is aimed at leveling the surface of the field and eliminating weeds. In the presence of irregularities, field leveling is carried out. It is especially effective for winter crops and soils of heavy granulometric composition, where plants are often soaked.
Previously the soil is ploughed or tilled with polydisc-tillers to a depth of 12-14 cm, then treated with levellers or heavy levellers. The best quality of leveling is provided with diagonal-cross method of aggregate movement.
For pre-sowing leveling the soil are used levellers ВП-8, ВП-8А or combined aggregates such as РВК-3,6, РВК-5,4 etc. Leveling the surface contributes to uniform embedding of seeds and emergence of seedlings, prevents the soaking of plants. For small-seeded crops it is advisable to use cultivators with lancet or knife-shaped tines, additionally equipped with loops. On light soils, pre-sowing rolling is carried out. On loosened peat soils the cultivation is replaced by harrowing and rolling, or it is processed by disc-tillers with an angle of attack of 15-17° with simultaneous looping or harrowing.
Tillage for surface and radical improvement of meadows, pastures and hayfields
Natural forage lands – hayfields and pastures with irrational use and lack of care reduce productivity by 3-5 times. For example, in Altai Krai about 5 million ha of natural forage lands, more than 800 thousand ha of which are floodplains, about 1.5 million ha are located on saline soils and about 3 million ha – on dry lands and slopes. After improvement their productivity increases by 2-3 and more times, and on saline soils and dry lands after tillage and reclamation measures – by 5-7 times. The contour development of floodplain lands of the middle level of the Ob River in the experimental farm named after V.V. Dokuchaev allowed to increase the hay yield from 0.5-0.6 to 4.0 t/ha.
Methods of improving natural hayfields and pastures include:
- The system of surface improvement.
- The system of radical improvement.
The system of surface improvement
The system of surface improvement includes methods of improving water, air and nutrient regimes of soil for the existing natural herbage, maintaining hayfields and pastures in cultural condition without complete destruction of turf.
Surface improvement is carried out when rhizomatous and loose-bush grass make up not less than 40% of the natural herbage. It is inexpedient if dense-bushy grass prevails, in this case the radical improvement with the complete destruction of the natural herbage with the following seeding of cultural grass mixtures is carried out.
Surface improvement of meadows and pastures includes measures to increase their productivity, improve the quality of fodder with complete or partial preservation of natural vegetation. It is carried out on unvegetated, unhidden meadows and pastures.
The basic techniques of a surface improvement system include:
- removal of tree and shrub vegetation that has no soil-protective value;
- removal of bumps;
- clearing of stones and garbage brought with water to floodplain meadows;
- weed control and rejuvenation of grass by discing or milling;
- fertilizing;
- complementary sowing of perennial grasses.
If necessary, the system of surface improvement may be supplemented by mole cutting on overwatered meadows, on sloping lands with heavy soils, not weeded by root-shoot weeds – slitting to a depth of 40-60 cm to increase water permeability and reduce water runoff, soil washout.
In the forest zone, tree and shrub vegetation on meadows and pastures are removed mechanically or chemically. Shrubs and small woods are cut with brush cutters, such as МП-2В, ПД-17, МП-8 or bulldozers in late autumn on frozen ground or in winter. Cut woody vegetation is raked into piles, dried and burned. On peatlands, in order to avoid peat fires, woody debris is taken out or burned in fire-safe areas.
Small shrubs up to 1-1,5 m in height on soils with thickness of humus horizon not less than 22 cm are plowed with bush-bog or plantation plough to the depth of 25-27 cm, so that the soil layer completely covers the wood. On peat soils the shrubbery up to 1,5-3 m high is plowed (embedded) to 30-32 cm and more. Decomposition of woody vegetation in this case occurs in 2-3 years in mineral soil and 3-4 years in peat soil.
For reclamation works on overgrown drained peatlands, milling machines МТП-42А, МТП-44Б are used, which simultaneously shred shrubs 3-5 m high, mix them with the soil to a depth of 35-45 cm, destroy bumps and roll the soil. For shredding the wood and its embedding at a depth of 23-25 cm the ФКН-1,7 milling shrub cutters are used.
Herbicides such as 2,4-D dichlorophenoxyacetic acid derivatives are used to eliminate tree and shrub vegetation that have no soil and water protection value. Butyl ether 2,4-D at doses of 2.5-3 kg/ha diluted in 100 l of water at ground spraying is especially effective. The preparation quickly penetrates into leaves and enters all plant organs. Leaves wither within a week, trunks and roots within a year. Withered trees and shrubs are eliminated mechanically, gathered in piles and burned. Destruction of all shrub vegetation in places of river washouts, slopes and dry meadows of the steppe zone is not allowed.
The presence of moles in meadows and pastures reduces their productivity and makes it difficult to harvest grass. Grass, small mole and ant mounds are destroyed with pasture harrows or heavy levelers. Larger mounds are killed with bog mills, heavy disc harrows, and rail-heavy levelers. On peat bogs, sedge mounds 40-70 cm in height are cut by shrub cutters type КПД-2 or bulldozers. Work on the removal of mounds is carried out in the fall or early spring, so as not to damage the plants.
After the removal of the bumps, the surface of the area is leveled, rolled and the grass is seeded.
Often meadows located in floodplains, closed depressions on dry lands, in lowlands with a slight slope, there is excessive moisture. Stagnant water leads to death of valuable species of grasses that cannot tolerate flooding, reduces productivity and quality of fodder. Stagnant water in this case is diverted by drainage canals.
In arid zones to improve the water regime additional irrigation is carried out, which is realized by construction of ponds, reservoirs, liman irrigation systems.
To improve the air regime and physical properties of the soil, activation of microbiological activity during grass rejuvenation harrowing, discing, milling are carried out.
Rejuvenation of grass on meadows with rhizomatous plants is carried out by single milling or double discing to a depth of 6-8 cm with simultaneous application of fertilizers and soil rolling, followed by supplementary sowing of grass mixtures.
On meadows and pastures with light and medium loamy soils with sparse herbage, loosening at 5-6 cm with pasture harrows type ПБЛ-5 is carried out. On floodplain meadows with medium thickness turf and rhizome cereal grass loosening shall be carried out by БПШ-3,1 and BMШ-2,3 harrows. For tillage of hayfields and pastures with dense turf on medium and heavy loamy soils – with heavy harrows БДТ-3, БДТ-7 to a depth of 8-10 cm in two directions.
On floodplain meadows with deposition of silt spring loosening and leveling with pasture harrows is carried out. On dry lands with sparse herbage, harrowing is carried out in early spring to preserve moisture.
For surface improvement of hayfields and pastures, the resource-saving technology of grass sowing without tillage of the whole turf is introduced (V.P. Kosyanenko, A.I. Stolyarov, 2001). Russian and foreign practice has shown that this method of sowing grass increases labor productivity, reduces the time of work, saves fuel, and prevents the risk of water and wind erosion of soil. The technology consists in destruction of the turf and loosening of the soil only in the row of sowing, making a furrow, sowing, embedding the seeds and compacting the soil in the furrow. The peculiarity of the method of sowing is cutting a strip of turf in the row of sowing, overturning, moving and crushing this strip to the untilled inter-row. In the resulting furrow, a vertical slit is cut into which the seeds are sown. The roller moves following, which rolls the soil. To use this technology, the combined aggregate МППТ-4,0 is used.
System of radical improvement
The system of radical improvement consists in increasing the productivity of natural forage lands by full replacement of natural grass with sowing of high-yielding varieties and species of perennial grasses. Radical improvement is carried out in case of severe thinning of grass stand of meadows, pastures, with less than 25-30% of valuable forage grasses and when more than 20% of lands are covered with shrubs, mounds, swampy areas.
The system of radical improvement consists of:
- clearing the land from shrubbery, small forests,
- removal of stumps, stones,
- removal of bumps,
- primary tillage of the turf and its cutting,
- fertilizing,
- main tillage,
- pre-sowing preparation (leveling, rolling),
- grass sowing.
Primary tillage is carried out to shred turf, deprive it of viability, eliminate weeds, create a deep arable layer with high biological activity and optimal soil conditions for sowing and grass growth.
The choice of tillage methods is determined by type of meadow, steepness of slope, thickness of turf and humus layer, weediness.
On low-lying meadows, drained peatlands and other lands overgrown with small shrubs up to 2 m tall, plowing without prior cutting of turf is carried out with full turnover of layer. For this purpose bush-marsh ploughs of ПБН-75, ПКБ-75, ПБН-6-50 type are used. For the best embedding of shrubbery, the depth of plowing should be not less than 25-27 cm on mineral soils and 30-35 cm on peat soils.
Strong-turf meadows and peat bogs free of shrubs are tilled before plowing with bog mills, for example, ФБН-1,5, ФБН-2, combined milling units АЗ-2,4, АЗ-3,6 or several times discing to a depth of 8-10 cm in a cross direction with heavy disc-tillers. Shredding of turf and peat layer accelerates their decomposition and provides a better quality of plowing.
After plowing (embedding) powerful turf and shrubs in the next 2-3 years, non-moldboard tillage is carried out to avoid their turning out on the surface.
Weakly-turfed dry and floodplain meadows with a thickness of the humus layer more than 15-17 cm plowed with plows with skimmers to the depth of the humus horizon.
On lowland waterlogged meadows and soils with temporary excess moisture in the presence of gley horizon is plowed with plows with notched bodies of 32-35 cm. In this case the upper humus layer of 15-18 cm is turned over and the subsoil layer is loosened simultaneously.
Non-moldboard tillage is used on dry meadows located on sloping lands with thickness of humus layer less than 15-17 cm and in areas with wind erosion. It consists of multiple tillage with disc harrows to the depth of humus layer and/or single milling. Then it is followed by non-moldboard loosening to the depth of 30-35 cm by ripper type РВШ-0,8, chisel tools ПЧ-4,5, ПЧ-2,5.
To protect soils from water erosion, sloping lands with a slope of more than 8° are plowed and planted with perennial grasses (create a meadow) in strips 15-20 m wide, alternating them with unplowed ones. After two years of development, when strips with seeded grasses are well rooted, plowed and planted with perennial grasses remaining strips.
After plowing the layer is separated by multiple discing at 14-16 cm with heavy harrows in combination with tooth harrows. Processing is carried out in transverse and diagonal directions in relation to the direction of plowing. Intensive crumbling of the layer on non-stony soils is achieved by using milling machines and milling cultivators КФГ-3,6. Before sowing, the surface is leveled by steam cultivators, toothed harrows, heavy levelers, and is rolled with ring-spiked rollers, and on peat soils – by smooth water-soaked rollers.
Main tillage of dry meadows with normal moisture is carried out in autumn, plowing of floodplains – in spring after the flood.
Primary tillage in the forest-steppe and steppe zones consists of turf treatment with disc implements, plowing with ploughs with skimmers to the depth of humus layer, as a rule, by 20-22 cm. On lands prone to wind erosion, non-moldboard plows of paraplau type, with SibIME tines are used for tillage, on light soils – flat-cut cultivators. Loosening depth is 28-30 cm.
Non-moldboard layer-by-layer tillage is applied on shallow and medium-column saline soils with humus layer up to 10 cm, including discing of turf in 2-4 treads and non-moldboard loosening to the depth of 30-35 cm.
Ameliorative three-tier tillage to the depth of 35-45 cm increases fertility of medium and deep columnar saline soils with near occurrence of gypsum and carbonates.
The composition of grass mixtures is determined by soil and climatic conditions, the way of grass stand use, for example, hayfield or pasture, the expected terms of its use: short-term – 2-3 years, medium-term – 4-6 years and long-term – more than 6 years.
Among perennial grasses used for creating meadows are bromegrass (Bromus inermis), wheatgrass (Agropyron), meadow fescue (Festuca pratensis), rootless couch grass (Elytrigia ?rhizome-free?), bromegrass (Psathyrostachys juncea), meadow timothy (Phleum pratense), Dactylis glomerata, alfalfa, sainfoin, Melilotus, clover, etc.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Fundamentals of Agronomy: Tutorial/Y.V. Evtefeev, G.M. Kazantsev. – M.: FORUM, 2013. – 368 p.: ill.
Tillage of soils prone to wind erosion
Tillage of soils prone to wind erosion – a set of cultivation techniques aimed at protecting the soil from wind erosion.
The causes of wind erosion are high wind speed at the soil surface, a high degree of spraying with weak topsoil structure, its low moisture content and lack of protective plant cover. Soil erosion often occurs on cultivated lands whose tillage technology does not match the landscape conditions.
The tasks of tillage of soils prone to wind erosion include:
- loosening the soil while keeping the maximum amount of stubble and other plant residue on its surface;
- creation of optimal conditions for moisture accumulation and retention in the soil;
- preventing soil dispersion and enhancing its aeration by minimizing tillage.
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion (Русский Español)
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction
Navigation
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion
- Tillage of soils prone to wind erosion (Русский Español)
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction
The stubble left on the surface of the field reduces the wind speed in the near-surface layer of the ground to 3-4 m/s, thereby preventing the soil from blowing out. In winter it allows to retain snow, contributes to moisture accumulation, and in the hot summer period it reduces its evaporation.
Scientists of the former All-Russian Research Institute of Grain Farming together with the institutes of Kazakhstan, Siberia, Trans-Ural and other regions under the leadership of Academician A.I. Barayev have developed soil-protective system of agriculture for steppe regions, for the development and implementation of which the Lenin Prize was awarded. Academician A.I. Barayev laid down the theoretical foundations of anti-erosion tillage of soils subjected to wind erosion, which are as follows:
- soils resistant to wind erosion should be classified as soils, the content in the upper layer of which is more than 50% of structural aggregates with a size of more than 1 mm.
- Covering more than 40% of soil surface with plant residues and stubble allows reducing wind speed in the near-surface layer to 3-4 m/sec, which reduces moisture evaporation, increases soil moisture content and, as a result, increases wind resistance.
Based on these principles, the anti-erosion tillage is based on flat-cutting without overturning with retention of most of the stubble on the field surface.
Soil-protection system of tillage, developed in the All-Russian Research Institute of Grain Farming, is used in the steppe regions of the North Caucasus, Western Siberia, the Lower and Middle Volga region, the Southern Urals and other arid regions of Russia.
According to the data of A.I. Barayev and E.F. Gossen, the yield of spring wheat on average for ten years at autumn flat-cutting in comparison with autumn plowing is higher by 0.48 t/ha. At Turgay regional agricultural experimental station on average for eight years – by 0.35 t/ha.
According to Kustanay regional agricultural experimental station, snow accumulation due to stubble preservation on the surface increases by 2 times, and the increase in yield of spring wheat on average for ten years is 0.38 t/ha.
On light loamy and sandy loam soils stubble does not provide complete protection of soil from wind erosion. For this reason on such soils Kustanai station recommended in addition to non-moldboard tillage apply strip planting crops width of 30-50 m. They are sown with spring wheat, and buffer strips 30 m wide – with agropyron and melilot.
The proposed tillage system consists of:
- rejection of the plow and other tillage implements that embed crop residues;
- tillage with flat-cutting implements that retain stubble and plant residues on the surface.
In addition to the basic techniques are used:
- introduction and development of soil-protective crop rotations with strip
- placement of annual crops and perennial grasses;
- strip planting of fallows and cereals;
- use of strip fallows;
- use of herbicides;
- use of hoe harrows instead of tooth and needle harrows for spring moisture closure and fallow tillage for better stubble retention;
- use of stubble seeders, such as СЗС-2.1, СЗС-8, СЗС-12, which combine mineral fertilizer application, soil loosening, sowing of cereals and soil rolling.
The use of implements with loosening flat-cutting working tools in the autumn tillage system allows to increase anti-erosion resistance due to less soil spraying and preservation of up to 75% of plant residues on the field surface.
Table. Methods and implements of anti-erosion tillage of soils subject to wind erosion
| Harrowing of autumn ploughed soil and fallows | Surface loosening of the soil by 4-6 cm. Elimination of weed sprouts, moisture retention | Needle harrows БИГ-3А, hoe harrows БМШ-15, БМШ-20 |
| Pre-sowing cultivation | Surface loosening of the soil by 6-8 cm, leveling the surface and trimming weeds | Rod cultivators КШ-3,6А, КЛШ-10, falt-cut cultivators КПГ-2,2, ОП-8, ОП-12, etc. |
| Cultivation of fallows in the system of autumn and spring tillage | Shallow flat-cutting loosening the soil at 8-16 cm with leaving stubble, trimming weeds | Flat-cut cultivators КПШ-5, КПШ-9, КПШ-11, heavy cultivators КПЭ-3,8, КТС-10-1, КТС-10-2 with rod devices |
| Non-moldboard loosening in the system of autumn tillage | Deep flat-cutting soil loosening at 25-27 cm with saving stubble and straw mulch, trimming weeds | Subsurface (flat-cut) deep tillers КПГ-250А, ПГ-3-100, ПГ-3-5, КПГ-2-150 |
| Non-moldboard loosening of perennial grasses | Loosening the layer of perennial grasses at 14-16 cm, trimming weeds | Tool for non-moldboard tillage ОПТ-3-5 |
For this purpose they use subsurface (flat-cut) deep tillers such as КПГ-250А, ПГ-3-100, ПГ-3-5, ploughs with inclined tines of paraplau type or with SibIME tines.
Strip fallows in steppe and forest-steppe areas prone to wind erosion are important in increasing the yield of cereal crops. Therefore, the system of tillage of strip fallow should be based on soil-protective methods of tillage. The autumn tillage is shifted to the spring period on the light soils with light granulometric composition, which are the most exposed to erosion. Stubble left after harvesting cereals and mulching with straw promote accumulation of snow, absorption of meltwater by soil, and protect the soil from blowing out.
In the conditions of black earth and chestnut soils to protect against spraying and water erosion, plowing is carried out to a depth of 27-30 cm or more. This allows to lift and mix from the subsoil layer to the top structural water-resistant soil aggregates, thereby increasing the resistance to wind erosion. This method is carried out periodically, alternating it with ordinary plowing.
In the arid southern regions, where winter wheat is sown after the stubble forecrop, non-moldboard flat-cutting is used. Up to 80% of stubble is retained on carbonate and chestnut soils, which reduces wind speed in the surface layer by 1,5-2 times, and the accumulation of moisture increases by 150-200 m3/ha.
For shallow surface spring tillage instead of polydisc-tillers and disc tools they use flat-cut cultivators type КПШ-5, КПШ-9, КПШ-11, КПЭ-3,8А in aggregate with a needle harrow. The use of such units allows to save up to 70-90% of stubble and plant residues and creates a mulching layer, and needle harrows level the soil surface.
For seeding cereals on fallow not weeded field, use press seeder СЗП-3,6 type, for seeding of the following crops after the fallow – seeders-cultivators СЗС-2,1, СЗС-6, СЗС-12, which together perform pre-sowing tillage, sowing, fertilizing and rolling of the sown rows. In conditions of overwatering, a hoe-sowing machine is more effective.
In the summer period to control weeds and prevent drying of the soil, as well as when taking care of fallow land use rod cultivators КШ-3,6А, КЛШ-10 or anti-erosion cultivators such as КПЭ-3,8, КТС-10-2 with a rod attachment. Rotating from the drive wheels at a depth of 5-7 cm square or circular rod breaks the root system of weeds and brings them to the surface, loosening and leveling the top layer of soil, creating a mulching layer.
Needle harrows with rotary hoe-type tools are used for postharvest autumn and spring loosening of stubble, moisture closure and seeding of weeds. This type of harrow can operate with any amount of stubble or straw on the surface of the field, saving up to 85% of plant residues, well loosening and leveling the soil.
In the fields of crop rotation deep loosening by deep rippers alternate shallow tillage by flat-cut cultivators. Thus, in five-field crop rotations deep loosening by deep rippers at 25-27 cm is carried out on a fallow field, and for the third crop after the fallow – to a depth of 20-22 cm. For the second and fourth crops tillage is carried out by flat-cut cultivator to 10-12 cm.
Important in terms of risk of wind erosion are methods of minimum tillage, contributing to increased soil moisture. It consists in reducing the number of passes of machinery in the care of bare and strip fallows and the use of herbicides.
Soil-protecting tillage methods ensure sustainable crop yields while protecting the soil from wind erosion, provided that crops are banded, the soil is mulched and other moisture-accumulating measures are taken.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.
Fundamentals of agricultural production technology. Farming and crop production. Edited by V.S. Niklyaev. – Moscow: Bylina, 2000. – 555 с.
Tilling of soils prone to water erosion
Treatment of soils prone to water erosion is a set of special methods of treatment aimed at protection of soils from the destructive effects of water erosion.
The cause of water erosion is the runoff of rainwater and meltwater, which washes away and erodes the arable layer and destroys soil fertility. Water currents carry away on the most valuable silty and colloidal fractions of soil, soluble humus and nutrients.
The main tasks of tillage of soils subject to water erosion are:
- imparting a fine lumpy structure and friable soil condition to improve water permeability and moisture absorption;
- creating a certain micro-relief on the slope surface;
- reducing soil washout with surface water runoff and its accumulation in the soil;
- deepening of the arable layer;
- destruction of plow pan.
Erosion control techniques can be divided into two groups:
- techniques increasing water permeability and filtering water;
- techniques that create micro-relief on the surface to retain water runoff and soil washout.
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion (Русский Español)
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction
Navigation
- Main tillage
- Surface and shallow tillage
- Sowing (planting)
- Post-sowing tillage
- Special methods of main tillage
- Tillage system
- Minimum tillage
- Deepening and improvement of the arable layer
- Tilling of soils prone to water erosion (Русский Español)
- Tillage of soils prone to wind erosion
- Tillage of reclaimed land
- Evaluation of the quality of fieldwork
- Problems of energy conservation and soil compaction
Erosion control treatments that increase water permeability and infiltration into the soil
The erosion control techniques of tillage that increase water permeability and water infiltration include:
- plowing across the slope;
- plowing with ploughs with deepeners or notched mouldboards;
- deep non-moldboard tillage;
- slitting;
- molling.
Methods of main tillage of slope lands depend on moisture, properties of arable soil layer and underlying rocks, soil flush, slope angle.
Plowing across the slope direction is carried out at a slope of up to 3° with rectangular configuration of the field. On complex slopes plowing is carried out along the horizontal contours of the slope, also called contour tillage.
According to the Volga Research Institute of Hydrotechnics and Land Reclamation, even ordinary plowing across the slope prevents water runoff. The amount of runoff largely depends on the depth of plowing. At deep transversal plowing due to greater water retention in the soil, cereal crops yields increase by 0.2-0.3 t/ha.
At contour-meliorative organization of field area is tilled in the direction of linear water-regulating boundaries, for example, shafts-terraces, roads, watercourses, forest belts, etc.
Agrotechnical requirements for plowing of sloping lands:
- maintaining the contour of furrows and ridges;
- maintenance of designed height of windrows (0,4-0,5 m) and their normal profile;
- maintenance of tillage depth;
- providing of good crumbling of layer;
- preventing from mechanical damage to watercourses sown with grass;
- hydro-forest-melioration and other constructions.
Quality of embedding of fertilizers, turf, plant residues, as well as leveling of furrows are of great importance.
The ridges and furrows formed during plowing across the slope serve as an obstacle in the way of water runoff down the slope, slowing down its speed. As a result of water retention and penetration into the soil, surface runoff is reduced by 3.5 times. According to generalized experimental data runoff of melt water is reduced by 77-94 m3/ha, in years with prolonged snowmelt and insufficient soil moisture – up to 200 m3/ha in comparison with plowing along the slope. At the same time cereal crops yield increases by 0.15-0.2 t/ha.
The depth and method of treatment of soils prone to water erosion depend on the slope. Plots located in the lower part of the slope, where the angle is less and the upper layer is more humusy, plowing is carried out to the depth of humus horizon. Soil of the upper part of the slope is more washed away, so plowing with soil deepening or no-till is used.
One-sided slopes are ploughed on rectangular paddocks, located across the slope. Fields with difficult slope relief break into irregularly shaped areas, taking into account the direction and steepness, which plowed separately mounted or turnover plow. At the same time the turnover of layer should be in the direction of the upper part of the slope, and the soil did not move down the slope.
Plowing with ploughs with deepeners, with notch and non-moldboard bodies is effective on medium- and highly washed away soils with a thin humus layer up to 20 cm.
When contour plowing, additional loosening of the subsoil layer is carried out without bringing it to the surface. Studies conducted on dark-gray heavy loamy forest soils of the state farm “Kashirsky” in the Moscow region showed that plowing with a deepening to 27 cm allowed to reduce soil washing out on the fields with a 3-5° slope by 5 times and to increase barley yield by 0.3 t/ha compared with plowing at 20-22 cm. The best results (120 m3/ha) this method gives on the sloping lands of the Central Black Earth zone.
Table. Meltwater runoff during plowing across the slope with deepening, m3/ha (according to Rozhkov, 1983)
| Non-Black Earth | Sod-podzolic and gray forest | ||||
| Central Black Earth | Black earth and gray forest soils | ||||
| Middle Volga region | Black earth and light chestnut soils |
Humus layer of small thickness on sloping lands is exposed to water erosion and constantly decreases, so annually include a small part of the underlying soil-forming rock, usually of heavy granulometric composition, into the cultivated arable layer. Involvement of clay admixture of bedrock leads to deterioration of soil properties, increasing its density, reducing water permeability. On such soils it is expedient to use plowing with ploughs with notched blades, providing continuous loosening of subsoil layer.
With deep loosening the soil freezes to a shallower depth and thaws earlier in spring. Melt water is absorbed by the soil, thus reducing flushing, water runoff, and its reserves are increased by 120-150 t/ha compared with plowing.
On soils subjected to strong washing away, the turnover of the layer is undesirable, so for processing plow-riders type ПРК-4-40, chisel tools, subsurface (flat-cut) deep tillers are used. Non-moldboard loosening is combined with plowing and polydisc-tilling. Performed it on the autumn plowing strip width of 4-6 m every 15-20 cm to stable freezing of the soil. This method increases the filtration capacity of the soil. According to the data of the Soil Institute named after V.V. Dokuchaev, deep strip loosening decreases washing away of sod-podzol soil on the slopes of 2-4 ° in 2 times, the cereal crops yield increases by 0.6 t/ha.
Deep non-moldboard tillage is carried out on heavily washed out slopes that are not weeded. On weedy areas, alternation of non-moldboard loosening and plowing is used. On poorly-washed slopes with a steepness of 2-4°, conventional plowing with soil deepening is used.
Special methods of treatment of soils prone to water erosion – slitting and moles, are carried out to regulate surface water runoff on slopes with the angle of 3-10°, which reduce soil washout, increase water reserves by 370-550 m3/ha due to transfer of surface runoff into subsurface runoff. Nitrogen, phosphorus and potassium losses with water are reduced by 3-4 times.
Slitting is used on heavy soils with poor permeability in the system of autumn tillage, on crops of winter crops, perennial grasses, hayfields and pastures. Slits 3-8 cm wide and 40-60 cm deep are cut in pairs (tapes) at a distance of 1.4 m between them. The distance between the tapes depends on the slope and is 5-10 m. On difficult slopes the strips are made discontinuous. Slitting is carried out in late autumn when the top layer of soil freezes to a depth of 5-7 cm to protect the slits from swamping.
Slitting makes it possible to increase moisture reserve in meter layer of soil up to 1000-2500 m3 of water per 1 hectare. In a number of farms in Podgoreny district of Voronezh region slitting of sloping lands allowed to increase moisture reserves in the soil up to 1600-2500 tons per 1 ha, which increased the yield of perennial grasses by 2.5 times.
For better water permeability and preservation of slits, they are filled with loose soil of humus layer mixed with stubble. Open slits are filled with water, which freezes and prevents the absorption of melt water. The greatest effect of this technique is achieved by cutting slits at the end of winter on still thawed soil and, if possible, covering them with a roll of snow.
Mounted slitters such as ЩН-3-70 and ЩН-4 or re-equipped ploughs, subsurface (flat-cut) deep tillers are used for crevicing. For slitting the ploughed autumn soil, they are equipped with roller-makers, which form water-retaining rollers of 10-12 cm in height over the slit. On crops of winter crops and grasses on slitters a disc knife is installed in front of each stand cutting through the turf and reducing damage to plants.
On hayfields and pastures located on the slopes of 8-10°, molling is carried out simultaneously with slitting, using slitter-moler ЩН-2-140 equipped with chisels and mole cutters. To prevent damage to plants of winter crops, grasses, ripping chisels are set at an angle of 10°, and when working on the autumn plowing field – at an angle of 30°.
On soils of heavy granulometric composition with poor permeability for regulation of surface runoff mole cutting (molling) is used. Mole cutting is creation on depth of 35-40 cm of parallel drains-moles with diameter of 6-8 cm on distance of 70-140 cm from each other. It is carried out by mole ploughs, mole-makers, on steep slopes – by rotary and shuttle ploughs. In steppe and forest-steppe regions in the spring period mole cutting contributes to the accumulation of water in the subsoil layer. In Kursk region mole cutting of soils increased the yield of winter and spring wheat by 0.27 t, barley – by 0.22, potatoes – by 3.7 t/ha, sugar beet – by 3.3 t in comparison with the ordinary plowing.
On fields with a field slope up to 3°, slits are created under rows of row crops at a depth of 30-40 cm, in which water and roots penetrate, which promotes the absorption of water and nutrients by plants in the deep layers. In legume plants, the number of root nodules increases.
The best results of slitting are achieved on crops of winter crops with their weak development in the autumn period. After sowing winter crops on the leveled surface of the field, meltwater runoff and soil flushing increases. Thus, autumn slitting reduces the surface runoff of melt water in the black earth soils of Voronezh region by 2 times, but it is not possible to stop water erosion completely with the help of this method.
Erosion control tillage techniques that create micro-relief on the surface
Agrotechnical methods of tillage that create microrelief on its surface in the form of ridges, closed wells, intermittent furrows, microlimans, or stepped profile allow to retain water runoff and prevent soil washing out. They include ridging, staggered, combined plowing, interrupted furrowing, hollowing of ploughed fields in autumn, creation of rolls of soil, etc.
In spring, fields with created microrelief are leveled by levellers, cultivators with harrows and other tools.
Stepped plowing
Stepped differently deep plowing – tillage, which creates a stepped profile of the bottom of the furrow. Developed by the Research Institute of Agriculture named after V.V. Dokuchaev. . Prevents surface an intra-soil water runoff. It is used in the fields with a slope of 5-8 °, where other techniques do not provide sufficient erosion control soil stability. More often such plowing is made by 4-corners ploughing the second and fourth corn plow at a depth of 20-22 cm, and the first and third – to 30-34 cm. Such plowing creates ridged furrows on the surface of the soil, and a stepped profile in the depth of the soil. The ridged-stepped profile prevents soil washing out and melt water runoff and retains up to 200-300 m3 of water per 1 ha.
Experiments conducted by the Research Institute of Agriculture of the South-East, Penza Agricultural Station and in the Rostov region, confirmed the high efficiency of soil-protective step plowing, which increased water reserves in the meter layer by 90-330 m3/ha, with an increase in cereal crops yield by 0.17-0.43 t/ha.
Ridge plowing
Ridge plowing is plowing, in which a ridge is formed on the surface of the field with a 3-5° slope. It is carried out by ploughs, where one, usually the last body has an extended mouldboard or one shortened, the other extended. Other combinations of bodies are also possible.
Due to the extended mouldboard creates a ridge (windrow) height of 20-30 cm, the shorter – the furrow. Alternation of ridges and open furrows in perpendicular to the slope creates additional barriers to the flow of water, which is absorbed by the soil, thus increasing its reserves by 150-200 m3/ha. Ridge plowing is combined with subsoil loosening, using soil deepeners, non-moldboard bodies or notched mouldboards for this purpose. Ridge plowing is carried out during late autumn tillage on one-side simple slopes.
Combined plowing
Combined plowing – plowing with a three-corners plough with removed mouldboards on the second and third corps or replaced by non-moldboard, which allows combining mouldboard and non-moldboard tillage. It was developed by Voronezh agricultural institute and is effective on the fields with a slope of up to 5-6°.
The combined plowing creates strips with stubble bordered with ridges on the arable land. In winter, snow accumulates in the strips, which protects the soil from deep freezing, which in spring contributes to the absorption of melt water. Application of combined plowing increases cereal crops yields on sloping black earth by 0.01-0.41 t/ha.
Intermittent furrowing
Intermittent furrowing is a method of treatment of soils prone to water erosion, which consists in cutting furrows on the surface of the field with a slope of 5-8°. It is carried out simultaneously with ploughing with ploughs equipped with special devices of ПРНТ-70000, ПРНТ-80000 types, which is a body with a shortened mouldboard, behind which a three-blade impeller is installed. Impeller during plowing, forming furrows 1,0-1,2 m long and with a capacity of 95-100 liters, interrupted by rollers (crosspieces) of height 20 cm. Thus, a closed system of microlimans, numbering up to 4000-4200 per 1 ha with a total capacity of 350-400 m3 of water, is created.
Intermittent furrowing along the soil compacted after plowing is also carried out by hilling cultivators in two passes. The first pass is carried out along the slope, the second – in the direction perpendicular to the slope. In this case, a network of closed wells of 0.7 x 0.7 m is formed, preventing water runoff and soil washing out.
Hollowing
Hollowing is a method used to create closed holes in the fields with a slope of 4-6°. It is done simultaneously with plowing with ploughs equipped with devices ПРНТ-90000, or separately with devices like ПЛДГ-5, ПЛДГ-10, disc-tillers ЛДГ-5, ЛДГ-10 or hole-forming devices ЛОД-10. The latter are spherical disks, which are periodically sunk into the soil and form holes. Up to 12 000 holes with total capacity of 200-500 m3/ha of water are created per 1 ha.
Pre-sowing soil preparation, sowing and plant care on sloping lands
Pre-sowing tillage of sloping lands includes:
- early spring harrowing of ploughed soil in the autumn,
- slitting,
- leveling the surface of the field,
- pre-sowing cultivation,
- contour sowing (planting).
Sloping lands with exposition (orientation) to the south and southwest reach physical ripeness in spring earlier than others. On such slopes the soil, dries out faster, that also concerns the top sections of slopes and fields with hollowing, furrowing. Therefore, on these soils carry out moisture closure first of all by cross harrowing with heavy tooth harrows.
Harrowing and cultivation
When sowing early spring crops harrowing is carried out simultaneously with cultivation. To do this in the fields with modified microrelief fallow heavy cultivators such as КПЭ-3,8, КПС-4, levelers ВП-8, ВПН-5,6А, ВИП-5,6, heavy levelers in coupling with tooth harrows are used. For better levelling of the surface double cultivation in cross direction with harrowing is carried out. Thus, a loose mulch layer is formed on the surface and capillary bonds are broken, which reduces moisture loss on evaporation.
Sloping lands, where non-moldboard tillage was conducted, warm up more slowly. Moisture is closed in this case by needle harrows in active loosening mode. For pre-sowing cultivation anti-erosion flat-cut cultivators such as КПШ-5, КПШ-9, etc. are used.
The depth of the first cultivation of heavy heavily leached soils prone to waterlogging is 10-12 cm with heavy cultivators КПЭ-3,8, КТС-10-1, which improve soil warming, embed fertilizers and facilitate the control of weeds. The first cultivation is carried out across the slope, the second – diagonally, as it will overlap the subsequent sowing.
Cultivation across the slope by extirpator cultivators and cultivation with simultaneous intermittent furrowing across the slope by cultivators equipped with furrow breakers are used for anti-erosion tillage of sloping lands when taking care of row crops and bare fallows.
In the crops of cereals and fallow fields as an agrotechnical method, cells with simultaneous rolling are created. For this purpose, special anti-erosion rollers are used.
Sowing (planting)
Sowing or planting on simple one-sided slopes is carried out in a perpendicular direction to the slope, on complex – along the contours, the so-called contour sowing. The rows of plants at contour seeding serve as a barrier for water runoff from atmospheric precipitation along the slope, reducing it by 25%.
Cereals are sown with ordinary row sowing method on slopes of 3-8°. If the slope is up to 3°, corn is sown with furrow method, potatoes – with ridge method, sugar beet – with dotted method.
To increase infiltration capacity of soil in row crops, slitting or intermittent furrowing is carried out to create additional capacity of storm water absorption. Slitting to a depth of 30-35 cm is carried out simultaneously with sowing or inter-row tillage. For this purpose, tilled cultivators are equipped with slitters and chisel ripping working tools. Slit cutting is carried out along the tractor’s wheel track or through 1-2 row-spacing. For intermittent furrowing and deep loosening of row-spacing a device ППБ-0,6 is used which is hinged on tilled cultivators and consists of an hiller and a four-blade impeller. When the latter is used, up to 4 thousand furrows are formed with bridges on 1 hectare to a depth of 16 cm and a total capacity of 250-280 m3.
According to the All-Russian Research Institute of Farming and Soil Protection from Erosion, intermittent furrowing between the rows at a slope of 2-3° makes it possible to retain up to 200 m3/ha of water while increasing the yield of green mass of corn by 1.8-2.0 t/ha.
To reduce the compaction effect of heavy wheeled tractors during tillage and sowing, additional rippers, which loosen compacted soil to a depth of 14-16 cm, are installed along the wheel track.
The use of organic and mineral fertilizers on sloping lands contributes to anti-erosion soil stability and increases crops yields by 20-40%.
On slightly and medium eroded soils, row crops are sown in wide-row dotted method across the slope, on more sloping slopes, sowing is carried out with the simultaneous creation of intermittent furrows in the row spacing.
Sources
Farming. Textbook for universities / G.I. Bazdyrev, V.G. Loshakov, A.I. Puponin et al. – Moscow: Publishing House “Kolos”, 2000. – 551 с.