System and advantages of primary tillage for spring crops

Autumn or spring ploughing: how to plan tillage for spring crops

Main tillage">Main tillage for spring crops is the first and deepest stage of field preparation after harvesting the predecessor crop. It is the autumn (winter) tillage that determines the structure of the arable layer, helps accumulate moisture, and improves the phytosanitary condition of the field. Postponing these operations until spring reduces equipment efficiency and leads to the loss of moisture accumulated over the winter.

The system of autumn tillage is customized for each individual field. The agronomist must take into account the predecessor — whether it was cereals, row crops, or perennial grasses. It is also important to assess soil and climatic conditions: particle-size distribution, moisture levels, and erosion risk. Based on this, the method and depth of tillage are selected: mouldboard, non-mouldboard, chisel, surface, or combined.

After harvesting winter and spring cereals, the field usually ends up compacted, infested with weeds, and contaminated with pathogens. The choice of tillage scheme depends on the degree of weed infestation and soil type. To restore the arable horizon, four main schemes are used:

• stubble cultivation (harrowing) and subsequent ploughing;
• stubble cultivation, ploughing, and surface tillage;
• ploughing and surface tillage;
• non-mouldboard ploughing and surface tillage.

Tillage technology: from stubble cultivation to depth adjustment

Stubble cultivation after solid-seeded crops is a mandatory starting stage of autumn work. This technological operation triggers a sequential chain of processes for cleaning and restoring the arable horizon. It should be performed immediately after harvesting the predecessor.

1. Loosening of the topsoil layer with a stubble cultivator to improve air access.
2. Drawing moisture from lower soil horizons to the top layer.
3. Triggered germination of weed seeds under the influence of heat and moisture in August — September.
4. Destruction of massive weed emergence by subsequent autumn ploughing or repeated cultivation.

Incorporation of crop residues with ploughs equipped with jointers reliably buries infection deep in the soil. This leads to the death of pathogens of rust, root rots, powdery mildew, smut, and ergot. Cultivation in August — September also sharply reduces the number of pests in the arable layer. During tillage, larvae of the wheat stem sawfly overwintering in cereal stubble are destroyed, which protects future barley, rye, and wheat crops. Furthermore, this period coincides with the moulting and pupation of wireworms — the tender click beetle pupae brought to the surface quickly perish from drying out, birds, and predatory insects.

In the climatic conditions of Belarus, August and September are considered the best time for autumn ploughing. Early tillage preserves the optimal structure of the arable horizon, ensures good soil friability, and allows for more moisture accumulation by spring. Due to the warmth during this early period, biological processes actively occur in the soil, accumulating available forms of nutrients for future crops. In addition, early ploughing stimulates weed germination, which then die from frost along with a portion of pests and disease pathogens.

• Depth of non-mouldboard tillage — 10–12 cm
• Depth of ploughing after maize — 20–22 cm
• Period of autumn ploughing in Belarus — August — September
• Period of harvesting row crops — September — October

Ploughing timing must be adjusted depending on the soil texture. Clay and loamy areas require earlier autumn tillage. Soils that are light in particle-size distribution should be ploughed later.

Non-mouldboard alternative and tillage after row crops

On cultivated fields, free of perennial weeds, classic autumn ploughing for potatoes, maize, buckwheat, and spring cereals can be replaced by non-mouldboard tillage to a depth of 10–12 cm. For this purpose, heavy disc harrows, chisel cultivators, or mouldboard-less stubble cultivators are used. This technique is effective provided there is spring organic fertilizers">application of organic fertilizers. Field studies confirm that for oats and barley, non-mouldboard tillage provides the same yield as classic mouldboard ploughing.

1. Perform the first non-inversion tillage immediately after harvesting the preceding crop.
2. Wait for mass emergence of weeds on the loosened soil.
3. Perform a second tillage pass in a cross direction.

Peas and vetch leave behind a well-structured, loose soil protected from compaction and clean of weeds due to their developed leaf canopy. After high-quality harvesting of these crops, the tillage system can be simplified by limiting it to chiseling or disking. However, lupine for seed is harvested significantly later. If weeds are present after it, full ploughing with jointer ploughs may be required.

After corn, flax, sugar and forage beet, as well as potatoes, autumn tillage is carried out in September-October. Due to the late timing, it is no longer possible to provoke and destroy weed seedlings in the autumn. Nevertheless, the intensive cultivation technology of row crops using herbicides and inter-row tillage usually leaves fields clean and loose. The final choice of autumn tillage technology here depends on the quality of the harvest, soil moisture, the volume of crop residues, and weed infestation.

After harvesting sugar and forage beet, the soil remains heavily compacted by the wheels of harvesting and transport vehicles, and plant residues lie on the field surface. The optimal method of primary tillage in this case is ploughing to a depth slightly less than usual. It allows for the incorporation of beet residues into the soil and effective loosening of compacted areas. If root crops are harvested cleanly, ploughing can be replaced by deep chisel tillage.

Soil after potato harvesting remains loose due to the digging technology itself. With high-quality tuber collection, deep inversion ploughing is not required. It is replaced by cultivation with harrowing or chisel tillage to 14–16 cm.

Soil preparation after perennial grasses and flax

Fields after perennial grasses differ from areas after cereals or grain legumes. A sod forms in the upper part of the arable layer — a densely intertwined root system and organic residues. Unlike cereals, the roots of perennial grasses are capable of regrowing after harvest. At the same time, post-harvest and root residues of legumes contain a lot of nitrogen and improve soil structure. The agronomist's task is to cut the sod and create conditions for its decomposition without losing nutrients. To fully incorporate the sod and prevent its regrowth, use ploughs with semi-helical or helical mouldboards for ploughing the sod layer.

The sod layer of perennial grasses is ploughed after the second cut or after using the aftermath. During this period, plant residues decompose completely, nutrients are not leached, and the farm receives the maximum yield of green mass. The timing of the work depends on the state of the grass stand and the type of grass. Thinned-out and weed-infested fields should be treated as early as possible. The sod layer after graminoid grasses is ploughed earlier, as they decompose more slowly than legumes, while ploughing after perennial legumes is carried out later.

Autumn tillage of fields after flax depends on soil weediness and harvesting technology. This crop is placed in rotation or after a layer of perennial grasses, so the field must remain free of weeds and have a good structure. The tillage method is chosen according to the situation:

• If the straw is not spread on the field, ploughing or chisel tillage is performed immediately after harvest.
• If infested with rhizomatous and root-suckering weeds, the field is first disked (stubble broken) and then ploughed with ploughs equipped with jointers or skim colters.
• If the straw was spread simultaneously with harvesting and the retted flax was lifted late, the field must be ploughed.

• Chisel tillage depth after potatoes — 14–16 cm
• Ploughing for flax after a grass layer — 1–2 cm shallower than the arable layer
• Ploughing the sod layer in northern regions — late August – first ten days of September
• Ploughing the sod layer in central and southern regions — second – third ten days of September