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.