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Farming in the steppe and forest-steppe regions of Siberia

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Farming system

Natural and climatic conditions

Climate

The steppe and forest-steppe regions of Siberia are characterized by a sharply continental climate with recurrent droughts 2-3 years out of 5 years, especially in the steppe part. Summers are short and hot. The warm period is 110-120 days, with fluctuations from 80 to 150 days. Daily air temperature in June-July is 35-40 °C, on the soil surface it is 50-55 °C. The sum of active temperatures is 1500-2300 °C. Early autumn frosts are possible, creating a danger for late-ripening crops and varieties.

Relative humidity may decrease to 10-12%. Winter period is long – 150-170 days, the minimum average temperature in December-February is -35 … -40 °C.

The average annual precipitation in the forest-steppe regions is 400-450 mm, in the steppe 250-300 mm and less (Kulunda steppe). Summer months account for 40-50% of annual precipitation. The driest period is usually June-first half of July.

Droughts and dry winds are typical phenomena. The probability of dry years varies from 45 to 88%. Number of days with wind speed over 15 m/s reaches 15-25, mainly fall in May-June, prevail in arid-steppe and semi-desert zones, especially in Kulunda steppe. Frequent and strong winds lead to the development of wind erosion of soils.

Soils

Soils of forest-steppe and steppe part of Siberia are mainly represented by ordinary, leached and southern black earths, dark- and light-chestnut, chestnut light soils. The share of areas occupied by saline soils and salts is high, in the north of the forest-steppe zone – gray forest and sod-podzol soils.

Soils of steppe areas are exposed to wind erosion, forest-steppe – to water and combined erosion. After large-scale development of virgin lands, soils have undergone significant changes: their structure has deteriorated, the content of organic matter has decreased.

Relief

The steppe regions of Siberia are dominated by plains, micro depressions (saucers), depressions and shallow valleys formed under the influence of the glacier and winds. The forest-steppe part is characterized by undulating and hilly relief with valleys of ancient runoff, gullies and ravines, formed under the influence of basins of the Ob, Irtysh, Yenisei, Ishim and their tributaries. Therefore, about half of the arable lands here are located on slopes of steepness of 3-5°, which leads to the manifestation of water erosion. On wind-impacted southern and southwestern slopes, manifestations of wind erosion can be observed.

Vegetation

Vegetation is specific. As a result of plowing of virgin and fallow lands, natural herbaceous vegetation represented by cereals and cereal-grasses was replaced by cultural vegetation. Spring cereals (60-70%) prevail in the structure of sown areas of agricultural land, of which 70-80% is the leading crop of the region – spring wheat. Forage crops, including perennial grasses, account for 23-25% of the total sown area, under bare fallow – 10-15%. Significant areas are occupied by potatoes, sunflowers, oil flax, camelina, mustard, sugar beet (in the Altai Territory).

A peculiarity of Siberian farming systems is the almost complete absence of winter crops, which leads to a large concentration and tension of field work in the spring period and during harvesting. In addition, it affects soil protection from erosion: the absence of vegetation cover in the autumn-winter period and early spring leads to the development of erosion processes. Therefore, the direction of breeding frost-resistant varieties of rye and wheat for conditions of steppe and forest-steppe regions of Siberia is promising.

Conditions of forest-steppe and steppe part of Siberia are not suitable for afforestation. Woody vegetation in the forest-steppe is represented in the small plots of woods, small groves and artificial plantings. Separate forest areas or complete absence of forest at high plowing of lands creates conditions of strong winds, drying the soil, contributing to the manifestation of black storms, which in winter blow snow from the fields.

The main tasks of the farming system

The main specialization of farming is – grain, meat and dairy and wool (sheep breeding), developed pig breeding, combined with grain direction.

The main factor limiting the yield is the deficit of moisture, characterized by frequent droughts and wind erosion of soils. These factors determine the main tasks of the farming systems of the forest-steppe and steppe of Siberia:

  • combating drought,
  • prevention of wind erosion,
  • improvement of alkaline soils,
  • elimination of weed vegetation.

Of particular importance is the observance of optimal sowing dates for spring cereals, taking into account biological and varietal characteristics, the use of agrotechnical and chemical methods of plant protection.

Crop rotations system

In the extreme conditions of Siberia, crop rotation becomes especially important.

In Siberia, the main rotations are cereal-fallow, cereal-fallow-row, cereal-fallow-grass, and cereal-row crop rotations. The first type predominates, as it allows to solve the main problem – increasing grain production.

Cereal-fallow crop rotations are the most productive in terms of grain. Thanks to bare fallows, the minimum needs of spring wheat in water and nutrients under arid climate conditions are ensured. By the time of spring wheat sowing, bare fallows accumulate 1.5-2 times more moisture in the one-meter layer of soil than after cereal or row crop predecessors.

The most productive by grains crop rotations are 4-5-pole cereal-fallows:

  • 1 – bare fallow, 2 – spring wheat, 3 – spring wheat, 4 – barley;
  • 1 – bare fallow, 2 – spring wheat, 3 – spring wheat, 4 – barley, 5 – spring wheat.

For the forest-steppe part of Siberia crop rotations are recommended:

  • 1 – fallow, 2-3 – spring wheat, 4 – corn for silage, 5 – spring wheat, 6 – barley, oats;
  • 1 – fallow, 2-3 – spring wheat, 4 – corn forage, 5 – corn for silage, 6-7 – spring wheat, 8 – alfalfa (4-5 years old field).

In the central and northern forest-steppe of Altai Krai cereal-fallow-grass crop rotations are economically and agrotechnically profitable. Their productivity from 1 ha of the crop rotation area for wheat grain, fodder and protein is 105-115 kg/ha per 1 fodder unit. Interchange schemes: 1 – fallow (bare or seeded), 2 – wheat + perennial grasses, 3 – perennial grasses of 1st year of use, 4 – perennial grasses of 2nd year of use, 5 – wheat, 6 – oats + vetch or oats.

On sloping lands with a steepness of 3-5° and active manifestation of water erosion, four-field soil-protective cereal-grass crop rotations are introduced: 1 – wheat with undersowing of perennial grasses, 2 – perennial grasses of 1st year of use, 3 – perennial grasses of 2nd year of use, 4 – wheat.

On steep slopes above 5°, bare fallows are replaced by seeded fallows or leguminous crops with striped placement across slopes with perennial grass buffer strips 15-20 m wide and 100-200 m apart taking into account steepness and exposition of the area.

Strongly eroded slopes with a slope of more than 8° are completely grassed with perennial grasses.

Field soil-protective crop rotations with strip planting of annual crops and perennial grasses are introduced on light soils.

In general, the following crop rotations are recommended for the regions of Siberia:

  • forest-steppe and moderately arid steppe regions:
    • 4-field cereal-fallow: 1 – bare (strip) fallow, 2-3 – spring wheat, 4 – barley;
    • 5-field: 1 – bare (strip) fallow, 2-4 – spring wheat, 5 – oats, barley;
    • 6-field cereal-fallow-grass: 1 – bare (strip) fallow, 2-3 – spring wheat, 4 – annual grasses, 5 – spring wheat, 6 – barley or wheat;
    • 6-field cereal-fallow-row: 1 – bare fallow (strip), 2-3 – spring wheat, 4 – corn (for silage), 5 – spring wheat, 6 – barley or oats;
    • 8-field cereal-fallow-row-grass: 1 – fallow, 2-3 – spring wheat, 4 – corn (barley, oats), 5 – corn for silage (annual grasses), 6 – spring wheat, 7 – spring wheat (grain forage), 8 – lucerne (derived field).
  • steppe and dry steppe:
    • 3-field cereal-fallow: 1 – bare fallow (strip), 2-3 – spring wheat;
    • 4-field: 1 – bare (strip) fallow, 2-3 – spring wheat, 4 – barley or oats;
    • 5-field: 1 – bare (strip) fallow, 2-3 – spring wheat, 4 – barley or oats, 5 – spring wheat;
    • 5-field cereal-fallow-grass: 1 – bare (strip) fallow, 2-3 – spring wheat, 4 – spring wheat + perennial grasses, 5 – perennial grasses (non-rotation field).
  • in semi-desert subzone:
    • 2-field cereal-fallow: 1 – bare fallow (strip), 2 – spring wheat;
    • 3-field: 1 – bare fallow (strip), 2 – spring wheat, 3 – fodder crops (millet).

In conditions of risk of wind erosion development 3-4-field cereal-fallow crop rotations are recommended with strip placement of bare fallow: 1 – bare fallow (strip), spring wheat, 2 – spring wheat, bare fallow (strip) and so on. Width of strips is 100 m.

Cereal-fallow crop rotations without row crops are used on saline soils:

  • 1 – bare fallow (strip), 2 – spring wheat, 3 – spring wheat and leguminous, 4 – vetch-oat mixture, 5 – spring cereals;
  • 1 – seeded (melilotus) fallow, 2 – spring wheat, 3 – spring wheat, etc.

Introduction of on-farm crop rotations is effective at enterprises with cattle breeding specialization. High yields of grain-forage crops in forage crop rotations are obtained in 2-3-year alternation with corn or millet sown for hay.

For cattle-breeding complexes with meat and dairy specialization grass-field with hay and pasture use, on-farm, saturated with silage crops, and forage, saturated with grain-forage crops, crop rotations are recommended.

At farms located near large cities and industrial centers, special vegetable crop rotations are introduced.

Tillage system

The main tasks of the tillage system:

  • prevention of wind erosion of the soil;
  • maximum accumulation and preservation of moisture;
  • weakening the effect of droughts;
  • effective control of weeds, pests and pathogens;
  • creation of optimal conditions for the growth and development of crops;
  • introduction of mineral and organic fertilizers.

Cultural plowing in the steppe regions of Siberia does not contribute to solving the problems of soil protection from erosion and moisture accumulation. Soil during autumn mouldboard plowing is deprived of plant cover and stubble residues, and is subjected to wind and water erosion. Snow is blown off the arable land into spikes and micro depressions. As a result, the soil freezes to a great depth and thaws only by June 5-10.

Flat-cutting autumn tillage after cereal crops allows saving up to 80-85% of stubble on the field surface, which delays snow, protects the soil from blowing out, contributes to less freezing and moisture accumulation. The reserves of productive moisture in the one-meter soil layer are 30-60 mm higher during the flat-cut tillage than during plowing.

In more humid forest-steppe regions of Siberia the system of tillage can be combined, combining the methods of non-moldboard, mouldboard and surface tillage. The preference for one or another method depends on local weather conditions, field condition, forecrop, features of the cultivated crop, topography, risk of erosion processes, and weed infestation.

In the conditions of Priobskaya forest-steppe of Altai Territory, where the amount of precipitation is 400-450 mm and the terrain is rugged, the non-moldboard tillage dramatically weakens the impact of water erosion. Yield of spring wheat increases by 0.2-0.4 t/ha. In dry years the increase in yields reached 0.4-0.5 t/ha.

In the Priobskaya subzone the following systems of tillage are used depending on the type of crop rotation:

  1. Cereal-fallow crop rotation:
    • 1 – bare fallow (strip) – autumn tillage after harvesting the forecrop or spring tillage with КПП-2,2. First tillage at the depth of 10-12 cm, second – 12-14 cm, cultivation with rod cultivator type КШ-3,6 at 6-8 cm as weeds grow and rains fall. Loosening with a КПГ-250 cultivator to a depth of 25-27 cm in August-September, in late autumn in October – loosening by КПГ-250 to 27-30 cm for better use of autumn-winter precipitation and to prevent development of water erosion in spring of the next year;
    • 2 – spring wheat – harrowing in spring with a needle harrow БИГ-3, pre-sowing cultivation КПЭ-3,8 equipped with a rod, sowing with a drill СЗП-3,6. After harvesting – main tillage КПП-2,2 at the depth of 14-16 cm;
    • 3 – spring wheat – spring harrowing with a needle harrow БИГ-3, pre-sowing cultivation КПЭ-3,8, equipped with a rod, sowing with a drill СЗП-3,6. After harvesting the main tillage with КПГ-250 at 20-22 cm;
    • 4 – oats – spring harrowing БИГ-3, pre-sowing cultivation КПЭ-3,8, sowing by СЗП-3,6 seeding machine, the main tillage with КПП-2,2 to a depth of 14-16 cm
    • 5 – spring wheat – spring harrowing of БИГ-3, pre-sowing cultivation of КПЭ-3,8, seeding by СЗП-3,6 type seeder.
  2. Cereal-fallow-row crop rotation:
    • 1, 2 and 3 – the fields are cultivated according to the scheme of cereal-fallow crop rotation. In dry years plowing corn replace flat-cutting loosening to a depth of 14-15 or 20-22 cm
    • 4 – corn for silage – autumn after harvesting spring wheat plowing to a depth of 23-25 cm with embedding organic fertilizers in a dose of 20-30 tons/ha. Harrowing in spring with a Zig-Zag harrow, pre-sowing cultivation, seeding with СЗП-3,6 seed drill. After harvesting, the main tillage with plough or cultivator-depth-loosener КПГ-250 at 20-22 cm.
    • 5 – spring wheat – spring harrowing БИГ-3, pre-sowing cultivation КПЭ-3,8, seeding by СЗП-3,6 seeding machine, the main tillage КПП-2,2 on depth of 14-15 cm;
    • 6 – oats – spring harrowing БИГ-3, pre-sowing cultivation КПЭ-3,8, seeding by СЗП-3,6 seeding machine.
  3. Cereal-grass crop rotation:
    • 1 – spring wheat – spring harrowing with a needle harrow БИГ-3, pre-sowing cultivation КПЭ-3,8, seeding with seed drill СЗП-3,6, tillage with КПП-2,2 to a depth of 14-15 cm;
    • 2 – spring wheat + perennial grasses – spring harrowing of БИГ-3, pre-sowing cultivation of КПЭ-3,8, seeding with СЗП-3,6 or a grain-grass seeder
    • 3 – perennial grasses of the 1st year – care according to accepted zonal technology;
    • 4 – perennial grasses of the 2nd year – care and harvesting according to accepted zonal technology, main tillage – plowing 23-25 cm deep, cutting of layer is made with heavy disc-tillers БДТ-7, БДТ-10. Weak perennial grasses may be cultivated with deep loosening cultivator КПГ-250 at the depth of 23-25 cm.

Terms of work and number of tillage operations may vary depending on weather conditions, weed infestation of fields, and other circumstances.

For the forest-steppe of the Trans-Urals in the Kurgan region, where wind and water erosion are weak, the main factor limiting the yield is drought. The tillage technology proposed by T.S. Maltsev in the late 40’s and early 50’s, based on a combination of deep and surface loosening, in these conditions is the most effective. The main tillage of fallow with non-moldboard tools is carried out at a depth of 27-30 cm, autumn tillage in the remaining fields of the crop rotation – disc-tillers to a depth of 10-12 cm in two trails.

In contrast to the flat-cutting system of tillage, designed for the maximum preservation of stubble as the main erosion control means, the system of cultivation by T.S. Maltsev gives stubble the role of mulching layer that preserves moisture and contributes to the accumulation of organic matter in the soil due to stubble and root residues.

According to the method of T.S. Maltsev, deep non-moldboard tillage is effective on meadow-chernozem soils, ordinary and leached black earths with heavier granulometric composition and on medium and deep columnar solonets.

In the north of the Siberian forest-steppe, which is characterized by sufficient precipitation and heavy soils, non-moldboard tillage is often used instead of plowing fallows and arable land in spring for row crops.

In the steppe and forest-steppe regions of Siberia, spring pre-sowing cultivation is used to provoke and destroy weeds. 

Types and terms of field work are specified for each farm taking into account weather conditions and technical equipment.

The care technology for bare (black and early) fallow in forest-steppe regions of Siberia is somewhat different. When preparing according to the scheme of black fallow, deep loosening or plowing is carried out after stubble loosening or discing to accumulate moisture in winter. Organic fertilizers are applied under plowing or superficially in autumn or the following summer.

Transferring the last (main) deep tillage of fallow from August to September or October makes it possible to reduce moisture losses for evaporation, eliminate the spraying of the top layer from repeated summer-autumn tillage and create additional pore volume to absorb spring melt water and reduce the negative impact of water erosion.

Fertilizer system

V.V. Dokuchaev characterized the black earths of Siberia as capable of producing good yields. At the same time, having a humus horizon of only 30-50 cm and humus reserves of 4-6%, they can quickly “wear out” and reduce their natural fertility if used improperly. V.V. Dokuchaev’s prediction was confirmed: after 8-10 years of improper use of new (virgin) lands without the use of fertilizers on large areas the fertility decreased significantly and the negative impact of wind and water erosion increased.

According to the results of the long-term study of different fertilizer systems in cereal-fallow crop rotations, the highest grain yield was obtained when P60 was applied in bare fallow. Nitrogen fertilizers give a confirmed increase in yield under the condition of application of an increased dose of phosphorus fertilizers.

The application of manure has a positive effect on the yield of spring wheat when it is applied in a fallow field. Manure application method – under the plough or deep loosening – does not matter: both methods of embedding provide the same increase in grain yield. The positive effect of manure is manifested during the whole rotation of crop rotation.

Leached and ordinary black earths in the forest-steppe, as well as in the steppe areas, contain little available phosphorus compounds for plants, which explains the high responsiveness of crops to the application of phosphorus fertilizers.

Phosphate fertilizers not only have a beneficial effect on nutrition, but also increase the drought tolerance of plants, 15-20% more productive use of soil moisture for yield formation. The efficiency of mineral fertilizers increases on fields where measures on moisture accumulation, for example, strip planting, snow retention with snowplows.

In the forest-steppe regions of Siberia, well-prepared manure shows high efficiency: making 20 t/ha in the fallow provides an increase in grain yield to 10 (?, probably 1.0) t/ha, taking into account its aftereffect.

Superphosphate is added to the fallow fall, locally by seeder СЗС-2,1 at a depth of 8-10 cm or by cultivator-fertilizer КПГ-2,2 at 10-14 cm. Special coulters for local application of mineral fertilizers are also used.

Nitrogen fertilizers to avoid overgrowth of vegetative mass, and lodging of wheat, make in accordance with the recommended zonal scientific institutions doses.

Soil protection complex

In the forest-steppe part of Siberia, most areas of agricultural land may be exposed to combined water and wind erosion. These processes are particularly strong in the Altai and Novosibirsk Priob’ye. Here the annual growth of gullies reaches 8-10 m, and the depth is 30-50 m. During heavy rains and melt water runoff flush of soil on sloping lands can reach 100 t/ha, in some years – 300 t/ha, with each hectare losing up to 80-100 kg of nutrients and 300-500 m3 of water, which aggravates the negative effects of droughts.

Anti-erosion measures carried out to combat drought, wind and water erosion in steppe and forest-steppe regions of Siberia taking into account local conditions:

  • placement of crops along the slope,
  • application of special methods of tillage and seeding,
  • deepening of the arable layer,
  • improvement of physical and mechanical properties of soil, etc.
  • contour-ameliorative farming system, including methods of agro-, hydro- and chemical reclamation,
  • complex agrotechnical and organizational-economic measures.

In Altai A.N. Kashtanov, RAAS academician, has developed a soil-protection complex, which is based on the principle of integrated use of water and land resources in contour-landscape area organization with application of agrotechnical measures on accumulation, conservation and rational use of moisture and meliorative measures, consisting in terracing slopes with slope more than 8°. To accumulate water in autumn-winter period, stubble is left, strip crops, snow-retarding and forest belts are applied. To reduce water evaporation from the soil, a certain soil treatment is used, green manure is grown, and a mulching layer of straw is spread. For irrigation, runoff water retained in the arable land and collected in reservoirs is used. Every year at the beginning of the season, depending on the moisture reserves in the fields, the placement of crops in the crop rotation and technology of their cultivation are specified.

Agromeliorative anti-erosion complex for the steppe part of Siberia includes bare strip fallows in crop rotations, flat-cut tillage with leaving stubble, snow retention by snowplows.

There is 30-50 mm more water in the one-meter layer of soil under a strip fallow, which allows you to get an additional 0.2-0.45 t/ha of grain of spring wheat.

Preservation of stubble during flat-cutting delays the first snow on the fields, which is almost completely blown away during plowing. The reserves of productive moisture in the one-meter layer of soil at flat-cutting are higher than at plowing: for the steppe subzone – by 20-30 mm, in the forest-steppe – by 35-45 mm. Additional snow retention with snowploughs of СВУ-2,6 type increases the thickness of snow cover and, accordingly, moisture reserves.

Accumulation and preservation of moisture in the soil is also facilitated by mulching with straw, which also has a positive effect on the balance of organic matter in the soil.

Plant protection system

In the steppe part of Siberia, the following are widespread: gray grain borer, wheat thrips, Swedish fly, spotted beetles, stem bread fleas, wheat flower mite, locusts, gophers, rodents, and in some years, the meadow moth. Cereal cicadas and aphids are dangerous as vectors of viral diseases of cereal crops.

Root rot, dusty mildew of wheat and barley, and mildew of oats and millet are widespread and harmful diseases. Powdery mildew, brown rust and wheat septoriosis, oat corking, barley reticular blotch are periodically harmful. Helminthosporiosis of barley and wheat grain (black germ disease) is observed annually.

Among weeds, the most widespread are:

  • vicious root-shoot and rhizomatous perennials: field thistle (Cirsium arvense), field thistle (Sonchus arvensis), Tatar hamster (Lactuca tatarica), field creeper (Convolvulus arvensis), couch grass (Elytrigia) and bromegrass (Leymus);
  • annuals: (Avena fatua), kurai (Salsola), Tartar’s highlander;
  • late spring weeds: green stubble (Setaria viridis), blueberry (Amaranthus), and annual and biennial weeds with a 1-3-year life cycle – Lappula, Artemisia, Henacle (Hyosyamus), Thistle (Carduus), etc.

Fallowing and qualitative soil preparation after non-fallow forecrop are the primary methods of controlling all types of weeds. Systematic flat-cutting cultivation concentrates up to 70-90% of weed seeds in the upper soil layer and partially – on its surface. The seeds which have wintered in the soil give more sprouts in spring than those which have wintered on the surface. Therefore, the tillage of fallow begins immediately after harvesting forecrop with the tools БИГ-3, КПШ-9 and КПЭ-3,8 which embed the crumbled seeds into the soil. Cultivators are more preferable in case of simultaneous weeding by oats, rhizomatous and root-shoot weeds.

Spring tillage of fallow begins after the mass regrowth of weeds.In early spring the first cultivation is carried out before sowing in order to prevent soil dehydration by oat (Avena), couch grass (Elytrigia) and awnless (Leymus) plants.

To effectively control root-shoot weeds, it is important to observe the timing of summer cultivation of the fallow.

A combination of two flat-cutting and two herbicide treatments of the fallow field is effective: the soil is cleaned from weeds and simultaneously provides anti-erosion protection, reduces fuel costs and labor costs.

When the fields are infested with couch grass (Elytrigia repens) it is necessary to carry out 4-5 times the cultivation of КПЭ-3,8 at the depth of the rhizome location – 14-16 cm or use the ОПТ-3-5 additionally equipped with cutter knives and rods-combers on paws-flat-cut scrapers.

Control of awnless brome (Leymus), rhizomes of which lie at a depth of 18-26 cm, consists of plowing fallows in early June at 26-27 cm and subsequent, as weeds grow, cultivation with cultivator КПЭ-3,8.

For the following crops after the fallow after harvesting spring wheat, harrowing by БИГ-3 with an angle of attack of 8-12° is carried out. A similar tillage is carried out after harvesting barley, if wheat crops follow it. Fallen seeds of cultivated and weed plants germinate better in spring and are destroyed by pre-sowing tillage. The tillage with БИГ-3 in the fall allows to embed the seeds in the soil and promotes more active germination in the spring.

The first tillage with БИГ-3 in spring in the fields where seeding is planned for May 22-23, is carried out 10-15 days before sowing with an angle of 16°, the second one – before sowing of crops. For sowing before May 15-20, they are limited to one pre-sowing cultivation.

In Siberia, the crucial factor for early weeds control, and especially wild oats (Avena), is sowing cereals at optimal time: from May 15 to 25 – wheat, and after May 25 to early June – oats and barley.

Pre-emergent harrowing in weed control is quite effective.

General measures of plant protection system:

  • effective and rational integration of the protection system into the farming system and crop technology;
  • implementation of agrotechnical and seed-growing measures aimed at suppressing the spread and development of pests;
  • mastering of crop rotations, observance of the order of alternation of crops;
    qualitative preparation of fallow and plowing fields;
  • qualitative holding of the main, pre-sowing and inter-row tillage of the soil;
  • observance of the optimal sowing dates;
  • harvesting in a short time and maximum reduction of crop losses;
  • efficient weed control;
  • creation of conditions for the reproduction of beneficial organisms and birds, for example, the use of field-protecting forests, grass planting, melioration;
    compliance with environmental protection measures.

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.