Main tillage is deep and continuous tillage performed for a particular crop in a crop rotation, which changes the density of the arable layer and mixes the layers or horizons of the soil.
The basic tillage may consist of general methods, such as plowing or deep loosening, and special – two- or three-level tillage, slitting soil, moling, etc.
Depending on the method of basic processing is subdivided into:
- mouldboard with full or partial turnover of the layer;
- non-moldboard loosening without turning the layer;
- tillage with full or partial mixing of the arable layer.
- Main tillage (Русский Español)
- 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
Navigation
- Main tillage (Русский Español)
- 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
Plowing
Plowing is a method of main tillage, which ensures turning of the tilled layer layer by at least 135°, loosening and partial mixing of the soil, undercutting the underground part of plants, fertilizers and plant residues. Plowing changes the composition of the arable layer, giving it a loose lumpy structure.
Increased aeration of the soil during plowing increases the activity of soil microflora, part of the seeds, seedlings and vegetative organs of weeds moves to the deeper layers, losing germination or dying off.
Types of plowing
Due to the wide variety of natural and climatic zones and soil properties, there are different types of plowing, the right choice of which determines the fertility of the soil and crop yields.
The most common types of plowing are shown in the figure (the cross section of the layers is shown without taking into account their deformations).
Plowing with full turn of the layer (in Fig. I) – the most ancient type of cultivation, which was used in the development of the steppe virgin lands. The main task of plowing virgin lands is to destroy the vegetation cover, deprive it of its vitality. Plowing with full turnover of the seam allows to achieve these goals, as vegetation, embedded in the bottom of the furrow, is completely deprived of sunlight and dies. Full revolution of the layer is achieved by using working tools with helical surfaces, provided that the width of the layer b ≥ 2a, where a – its thickness.
The swathing of the layer (in Fig. II) began to be used almost two centuries ago in the cultivation of cohesive sodded soils. Proceeding from the theory of mineral nutrition of plants, the main task of this type of plowing is to provide the largest surface of the arable land in order to maximize the impact of air, heat and light on the soil. This type of tillage is obtained by using helical working surfaces, when the width of layer b < 2a. When plowing with a plough, voids (grooves) are formed, which disturb the water-air regime of the soil, which leads to rapid drying of the soil. The plowing turns out ridge, but most importantly, it does not completely suppress the vitality of the turf. At the joints of layers, unconsolidated turf appears, and in the depths of formed furrows, rain moisture accumulates, which contributes to growth of unconsolidated and breaking through turf. To get rid of this deficiency with the help of anglosnim, a small triangular layer of soil is cut off from the field side, which is dropped to the bottom of the furrow (Fig. III). As a result, there is no turf at the joints of layers, and the layer cut by the anglosnim and dropped to the bottom of the furrow, as if it seals the joint from the bottom side, making it difficult for the turf to grow and come out to the day surface.
Cultural plowing, or plowing bodies with cylindrical (cultural) working surfaces and skimmers (Fig. IV), is used when processing light old arable soils, which in the process of their processing plows with screw working surfaces do not form a layer, and scattered on the structural units. The skimmer or dernosnim (jointer) cuts the tetrahedral soil prism from the layer and dumps it to the bottom of the furrow. In doing so, the main layer, being freed from most of the turf, is better crumbled and more completely embedded plant residues.
The skimmer’s working width is 2/3 the working width of the main plough body. If its working width is set equal to b, you get a two-tier plow (Fig. V). Double-deck ploughing is used for tillage of crops requiring increased working depth (e.g., beets, cotton).
Rhombic plowing got its name due to the shape of the cross section of the layer, resembling a rhombus (Fig. VI). The rhomboidal cross-section of the layer is formed as a result of undercutting the soil with two plows: one from the side of the bottom of the furrow, the other from the side of the furrow wall. The latter is made in the form of a part of a spherical disc. Rhombic ploughing allows getting a wide open furrow, in which right wheels of a tractor freely roll over. The disadvantages of this type of cultivation are high specific material capacity of technical means (1,45 … 1,9 times higher), not enough complete embedding of plant residues (58 … 97%), the possibility of turf reaching the day surface at the joints of layers.
Non-moldboard plowing (Fig. VII) is carried out periodically, usually once in 4-5 years, in areas of insufficient moisture, on soils subject to wind erosion and on slopes. It is carried out by plough bodies without mouldboards. Shoeless plowing is a type of deep loosening. The main task is to increase the water permeability of the soil and maximize moisture retention.
Plowing with soil deepener (Fig. VIII) is used on sod-podzolic soils with relatively shallow podzolic layer (podzol). Since when podzol is brought to the surface, soil fertility decreases, the cultural plowing with turnover of the layer is carried out to a depth equal to the thickness of the cultivated layer. Podzolic layer is only loosened by soil ploughs, as a result soil-forming processes start in it and in some years it becomes fertile.
Plowing with ploughs with cut-out bodies (Fig. IX) is used on sod-podzolic soils. The loosened podzolic layer passes through the plough body notch and remains at the bottom of the furrow, the cultivated layer falls on the plough body, is overturned, crumbles and buries the loosened podzolic layer. Thus, only a small part of the podzolic layer, rising on the lintel between the ploughshare and the mouldboard, mixes with the cultivated layer, forming inclusions. The resulting soil-forming process leads to the inclusions and increases the thickness of the layer.
Three-tier tillage (Fig. X) is applied on solonetz and podzolic soils. Three genetic horizons are often distinguished in columnar solonetz and podzols: upper humus fertile layer (marked with number 5 in Fig.), middle solonetz or podzolic infertile and even harmful for plants (number 6 in Fig.) and lower carbonate or illuvial layer rich in gypsum, lime and calcium (number 7 in Fig.). Of the three different methods of tillage proposed by different authors, the most common is the method of Academician V.P. Mosolov. It is based on the use of lime, gypsum and calcium contained in the lower carbonate or illuvial soil layer. According to this most economical method of reclamation the top fertile layer 5 is turned around and loosened, but remains in place, the middle infertile solonetz or podzolic layer 6 is moved down, and its place is taken by the lower carbonate or illuvial layer.
Smooth plowing – plowing without pile ridges and breakage furrows, which is carried out by plows designed for smooth plowing: turnover, front, shuttle, rotary, key and balancing. Ploughed field has a leveled surface, thereby providing more favorable conditions for plant growth and the work of machines performing the following technological operations. Yield of cultivated plants with smooth plowing increases by 5-10%, productivity of machines – by 10-15%, in addition, during harvesting the losses of crops are reduced.
In addition to the above types of plowing, in some circumstances use special types of tillage, such as on slopes step, combined and combined-step cultivation. At the staggered ploughing the plough bodies, alternating through one, have extended tines and therefore they till deeper, forming the stepped bottom of the furrow. In combined ploughing, shoeless and mouldboard bodies alternate. As a result, stubble remains in the passages of shoeless bodies, and the mouldboard bodies block it, forming ridges. Combined plowing is a combination of the two types of plowing. The main task of such types of plowing is to reduce water runoff on the slope, i.e. to prevent water erosion of the soil.
Plow designs
Ploughs with different bodies are used for plowing: cultural, screw, half-screw, cylindrical, cut-out, with a soil-deepener, with a retractable chisel, disc, etc. Degree of crumbling and turnover of layer depends on plough design, shape of moldboard and speed of movement.
Ploughs with half-screw and screw mouldboards turn the layer more strongly, but crumble it poorly. For this reason they are used on heavy and sodded soils, perennial grasses and virgin lands.
Cylindrical mouldboard crumbles the soil well, but the layer turnover is much less than that of half-screw and cultural mouldboards.
Combined moldboards are a combination of cultural and half-screw moldboards. The most perfect recognized plowing with plows with cultural and combined shape of the moldboard with skimmers.
Cultural mouldboards ploughs provide a good crumbling, layer turnover and embedding of crop residues of old arable land.For better crumbling and turnover, skimmers are installed, which additionally levels the surface, reduces the formation of clumps and reduces weed infestation of fields.
In conditions of irrigated agriculture, mountainous terrain and for better quality of plowing very heavy, sodded soils, special front turnover plows of ЛФ-2А type are used. This type of ploughing is called smooth ploughing.This plough is equipped with two bodies: right- and left-turning, which turn layer by 180 degrees and tilting it in one direction. In mountain conditions ridges and furrows are not created under slope. Additional housing, installed after the main – skimmer, undercuts the bottom ribs of layers and along with the main bodies stacks layers in the furrow. This creates a leveled surface of the field without ridges and furrows.
Disc ploughs are used to till stony soils. These ploughs consist of a number of spherical discs with cutting edges mounted on a common axis.
Ploughs are subdivided into:
- mounted ploughs (ПЛН-3-35, ПЛН-4-35, ПЛН-5-35, ПОН-5, ПОН-4-35);
- half-mounted (ПТК-9-35, ШШ-6-35, ПНИ-6-40, ПЛН-6-35);
- front (ПФ-2А);
- trailed (ПП-5-35).
Skimmer
Skimmer is installed in the front part of the plough body, which provides undercutting the upper part of the arable layer to a depth of 8-12 cm and a width of 2/3 of the width of the body, dumping it to the bottom of the furrow.
Ploughs with skimmers use when the depth of the arable layer is not less than 20 cm.This is due to the need to embed the top 10-12 cm layer, which is dropped into the furrow, by the underlying layer. It is especially important when incorporating turf. For this reason, soils with a thickness of the arable layer of less than 20 centimeters and homogeneous peatlands plow without skimmers.
The skimmers are not used when incorporating organic and green manure, or when it is necessary to mix them with the soil during the doubling of fallow, i.e. summer ploughing.
Agrotechnical requirements
Plowing over fallow the old plowing and primary plowing of virgin lands perform plow plows with skimmers. Replowing fallow and manure plowing carried out without skimmers. Tilled soils with a turnover, but without loosening the layer (for loosening used other tools).
The depth of plowing is determined by zonal features, the thickness of the arable layer and soil type, the features of the culture, as well as the depth of the main treatment of the preceding crops, weed infestation.
Plowing depending on the depth is subdivided into:
- shallow – less than 20 cm,
- normal – 20-23 cm,
- deep – 24-40 cm,
- plantation – more than 40 cm.
The depth of tillage is determined by the requirements of the cultivated crop, the structure and thickness of the arable layer and other factors. For most crops, the optimal depth of plowing is 20-22 cm, sugar beets – 25-27 cm, corn – 28-32 cm. Soils with insufficient arable layer are plowed to its full depth, gradually increasing it with the help of tillers, for example, for sod-podzolic soils by 4-5 cm annually.
Sod-podzolic soils are usually processed to a depth of 20-22 cm, well-cultivated and gray forest – to a depth of 26-28 cm chernozem soils for row crops is plowed to a depth of 28-32 cm.
As a result of annual plowing the plow bed is compacted. To break it, the depth of plowing is periodically increased to 25-27 cm or loosening with a cheziel plow. Quality of plowing should meet the established standards.
Plowing is carried out in agricultural terms when the physical maturity of the soil is reached: for clay – 50-65% of the lowest moisture capacity, loam – 40-70%. Wetter soils are less crumbly, the wheels and working bodies stick, which increases traction resistance of the plough and energy costs for plowing.
The timing of plowing depends on soil and climatic conditions, soil moisture and cultivated crop. Gradual tillage for spring crops is carried out after harvesting of preceding crops, spring plowing is carried out at physical ripeness. During cultivation of winter crops – 2-3 weeks before sowing.
On stony soils, ploughs with guards are used, and an angle cutter is installed on plough bodies to cut layer’s angle during its movement on the mouldboard.
For intensive crumbling of layer the ploughing can be combined with additional tillage with devices ПВР-2,3 and ПВР-3,5 attached to plough. At soil moisture of more than 70 % instead of these devices to the plough are attached tooth harrows.
Plowing speed should correspond to the speed set for the used bodies: 1.4-2.2 m/s for conventional and 2.2-3.3 m/s for high-speed ones.
Non-moldboard tillage
Non-moldboard tillage is a method of main tillage, which consists in loosening the soil without turning it around. It is widely used in conditions of insufficient moisture and in the treatment of soils prone to wind erosion. Non-moldboard tillage allows to cut the weeds and loosen the soil by leaving up to 50% of the stubble on the field surface, which retains the snow and decreases the wind speed in the surface layer by 1,5-2 times.
Frost penetration depth of soils cultivated with non-moldboard implements is less, which contributes to its earlier thawing in spring. Melt water is better absorbed by the soil, its runoff decreases, and water reserves in the soil increase by 1.5-2 times in comparison with the mouldboard tillage.
Deep non-moldboard loosening at 25-27 cm is carried out during autumn tillage in bare fallows, for preplanting loosening for potatoes, row crops and other crops. It is carried out by non-moldboard ploughs of T.S. Maltsev design, non-moldboard tools paraplau, ploughs with removed mouldboards, ploughs with SibIME tines, ploughs-deep loosening ploughs.
In Trans-Urals, the system of non-moldboard tillage developed by T.S. Maltsev (Shadrinsk Agricultural Experimental Station, Kurgan Region) has been widely used. It excludes plowing with overturning the layer. Deep non-moldboard loosening is carried out to a depth of 35-40 cm once every 3-5 years, combining it with annual shallow tillage: husking or discing to a depth of 10-12 cm. The top layer of soil in such a system does not move, enriched with organic matter of plant residues of annual crops.
Non-moldboard tillage worsens the phytosanitary state of the soil: seeds and vegetative organs of weed reproduction, pathogens of diseases are accumulated.
Chiseling
Chiseling is a method of main tillage with chisel tools, which provides loosening and partial mixing. Chiseling is used for continuous deep loosening without overturning the layer in the care of fallows, for crops of continuous sowing and tilled crops, for deepening and cultivation of the arable layer, for example, podzolic and saline soils. Loosening depth is 20 to 40 cm.
Chiseling allows loosening the plough pan and compacted layers, which facilitates penetration into deeper layers of water, air and plant roots. Therefore, it is used on heavy and saline soils during leaching and moisture-accumulating irrigation. This method is effective for deep loosening before planting in root crops, potatoes, and forage crops, especially on heavy and easily swamped soils.
For chiseling plows are used ПЧ-2,5, ПЧ-4,5, which are equipped with devices for ridge levelling ПСТ-2,5 and ПСТ-4,5.
Chiseling allows you to increase the yield of crops by 15-20%.
Flat-cutting (subsurface tillers)
Flat-cutting (subsurface tillers) tillage is a method of non-moldboard tillage with the flat-cutting tools saving up to 80-90% of the crop residue on the field surface, providing loosening of the soil to a depth of 8 to 30 cm with cropping of weeds. It is mostly used in the areas of wind erosion and in dry conditions, in the system of winter and spring crops pre-sowing tillage, during the care of bare and strip fallows.
The stubble left after ploughing reduces by 2 times the wind speed in the surface layer, decreases the intensity of summer moisture evaporation, contributes to snow retention, especially in years with insufficient autumn and winter precipitation. Yield increase of grain crops with flat-cutting in such conditions is from 0.2 to 0.4 t/ha.
The depth and number of flat-cutting tillage depends on soil and weather conditions, and field weediness. For deep (16-30 cm) flat-cutting tillage use subsurface (flat-cut) deep tillers, such as КПГ-250А, КПТ-2-150, ПГ-3-5, ПГ-3-100. For shallow (7-16 cm) – flat-cut cultivators КПШ-5, КПШ-9, КПШ-11.
For application of granulated mineral fertilizers during flat-cutting, flat-cut deep tillers of КПГ-2,2 type with special fertilizer devices are used. Mulching layer on the surface of the soil and a good crumbling are created by rod cultivators type КШ-3,6. Mulching layer helps to reduce the risk of wind erosion. These cultivators are used in preparation of the field for sowing winter and spring crops, as well as for continuous loosening of the soil during the care of fallow lands.
Flat-cutting tillage, despite its high soil-protecting function and lower energy consumption as compared with mouldboard tillage, worsens the phytosanitary condition of the soil. Therefore, in crop rotations it is combined with mouldboard tillage, introduction of bare fallows in crop rotations and herbicides application.
Rotary tillage
Rotary tillage (milling) is a method of basic soil cultivation with the use of milling cutters, providing intensive loosening and thorough mixing. One pass of the rotary tillage machine allows to prepare the soil qualitatively for sowing, so milling can replace plowing, cultivation and other methods of loosening.
As a rule, it is used on deeply sodded and peaty soils to accelerate mineralization processes.
The milling unit is a drum with spring tines and knives of different shapes. The drum rotates in the opposite direction to the machine’s movement, with the tines cutting into the peat or turf and throwing them back in small pieces, where they hit the protective grid and strongly crumble without forming clumps. Conventional plowing does not allow for such rapid soil breaking.
However, rotary tillage strongly disperses the soil, so after one or two tillage milling peaty and sodded soils switch to plowing with a plow with skimmers. Milling is also used in the radical improvement of meadows and pastures.
Rotary tillage depth for root crops, potatoes and vegetable crops is 15-20 cm for cereals – 8-12 cm. Milling is an effective method for inter-row cultivation of orchards, berries and row crops. With the help of special devices for milling, ridges can be cut.
Rotary tillage is combined with other methods: the application of fertilizers, herbicides, seeding, leveling and rolling the soil surface. To do this, use a combined seeding units, such as for grain crops КА-3,6, КА-7,2, which is a combination of a milling machine and a grain seeder, КФС-3,6 and others. Milling machines can be garden (ФПШ-200, ФСН-0,9A), field (КФГ-3,6, КФ-5,4), swamp (ФБН-2, ФБН-1,5), etc.
Rotary tillage increases the field germination of seeds, for example, cereals by 15-25%. Milling the over-watered soil before sowing leads to its swamping, which reduces the field germination and yield. Therefore, it is desirable to use this method in dry years.
Long-term application of milling in field crop rotations increases the weed infestation, especially root-shoot and rhizomatous weeds.
Organization of tillage in the field
The organization of work during basic tillage in the field includes:
- field preparation,
- determining the direction of plowing,
- choice of method of movement and work of the unit when plowing the paddock.
Preparation consists of:
- clearing the field of stones, straw, plant residues;
- leveling the surface;
- dividing the field into paddocks (sections);
- beating off of turn lanes;
- plowing control furrows and piled ridges.
Determining the direction of plowing
The direction and method of machine movement depends on the size, configuration of the field, length of the run, slope, and other conditions.
Plowing along the long side of the field is more productive than plowing along the short side. For fields more than 300 m wide, it is recommended to change the direction of plowing every year, which improves the condition of the soil.
On simple slopes, ploughing is carried out in the direction perpendicular to the slope runoff (i.e. across the slope or horizontally). On difficult slopes – along the contours, the so-called contour plowing. On leveled fields it is carried out in the direction perpendicular to the previous plowing. In conditions of risk of wind erosion – in perpendicular to the direction of prevailing winds. Under conditions of excessive moisture at a slope of 1-2° of the field, plowing is carried out along the slope, at a higher slope for more uniform drainage of excess water – along the field diagonal.
On slopes it is recommended to carry out plowing with reversible or shuttle ploughs.
When plowing with frontal ploughs there is no need to divide into corrals, since the movement is carried out by shuttle method.
Paddocks
Before tillage, the field is divided into paddocks (plots) with parallel sides, ensuring rectilinear movement of the machine. The strip of the first pass is marked with milestones (stakes) set at a distance of 50-80 m one from another.
The width of the paddock depends on the length of travel, the method of machine travel and the number of bodies on the plow. For this purpose, reference data or a chart is used.
Dimensions of turn lanes for turning aggregates:
- for МТЗ-80, МТЗ-82 tractors with three-hull plow (small tractors) – 0-12 m;
- for ДТ-75, Т-74 with four-hulled plough (for medium-sized tractors) – 12-15 m;
- for Т-150К, К-701 (for large, heavy tractors) – 24-30 m.
The piled ridge is plowed on all odd paddocks. As a rule, it is performed by plowing in three passes. During the first pass, the plough is adjusted so that the first body goes on the surface of the soil, and the last one plows to a predetermined depth. At the second pass all the plough bodies are set to the set depth and lead it in such a way that the first body walked on the penultimate one’s trail, partially filling in the open furrow at the first pass. During the third pass a low piled ridge is formed in accordance with the requirements.
It is recommended to plow alternately in ploughing and in ploughing for better alignment of the field. The piling ridge should be straight, and the depth of plowing under it should be not less than half of the specified one, its height should not exceed 10 cm.
The highest quality of plowing is obtained for four passes of the unit: after the first two passes (sloping) on the place of the future dump, a sloping furrow with width equal to twice the width of the plough body grip is formed; the third and fourth passes are performed in the opposite direction accordingly to the second and first passes. As a result, a relatively even surface of the field is obtained. The rumble furrow should be straight, equal to the working width of the plough body.
For making the first furrows and plowing the borders of turn lanes, the first passes of the machine should be made by plowing in three passes in a row or in a row in four passes of the machine. The plow for the first pass of plowing in ploughing is set so that the first body slides on the surface of the field, and the last plowed to a predetermined depth. The second pass is performed so that the first body, set at the set depth of plowing, follows the trail of the penultimate body. The third pass is carried out as during conventional plowing. For the first and second passes of plowing, the plough is adjusted so that the first body slides on the surface of the field, and the last body is deepened by half of the set plowing depth. After that all plough bodies are adjusted to the set depth and the third and fourth passes are made, directing the first body along the trail of the penultimate body at the second and first passes respectively. At the same time, a slump furrow is filled in and a small piled ridge is formed.
After all paddocks are ploughed, the headlands are tilled and split furrows are filled. For furrow plowing the plough is adjusted so that the first body plowed to the specified depth or 5-6 cm deeper and walked next to the open furrow, and the rear one slid on the surface of the field.
The way of movement of machines
When plowing the field, the following methods of machine movement are most commonly used:
- looping with alternation of paddocks in the pile and in the slump;
- combined loopless;
- circular without paddocks.
When starting plowing from the middle of the paddock, a piled ridge is formed in the middle of the paddock and furrows are formed along the edges. On the contrary, when starting plowing from the edges, a rutting furrow is formed in the middle of the paddock. When paddocks alternate between piled and slumped, the number of piled ridges and slump furrows in the field decreases.
For short driving lengths, a combined no-loop method is used whereby the first paddock is plowed into a slumped area as long as a no-loop turn is possible, the remainder of the paddock is plowed together with the adjacent paddock.
On levelled fields of rectangular or square shape with an area of at least 50 hectares the circular method is used without corrals. Plowing in this method is carried out in a circle, starting from the middle of the field to the periphery and vice versa. In the center of the field form a corral in the piled. Then at a width of corral 30-40 m it is ploughed in a circle with a left turn in the corners.
Circular method without paddocks allows to provide a smoothed surface of the field without piled ridges and slump furrows, increase productivity of the unit and reduce fuel consumption.Limitation of this method is complexity of field marking and uneven wear of machinery with constant left turn.
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.
Agricultural and Reclamation Machines. Klenin N.I., Sakun V.A. – Moscow: 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).