How to ensure uniform crop emergence?
All previously described agrotechnical operations lead to sowing the main crop. Once the seeds are placed in the soil, a waiting period begins—sometimes full of tension. Will the seeds emerge evenly? Will diseases affect them? Will the harvest be abundant? Crop protection and harvesting are discussed in other chapters; here we focus solely on sowing technique—how to ensure uniform emergence.
Sowing depth
For uniform emergence, seeds must “start” from the same level—each grain should be placed at the same depth (this is why the field surface or seed rows are levelled beforehand). Seeds should be placed on a lightly compacted soil layer from which capillary water rises, enabling germination.
- Too shallow: seeds dry out or are eaten by birds.
- Too deep: emergence is delayed and uneven.
For most cereals, the optimal sowing depth is 2–4 cm (slightly shallower on heavy, moist soils and slightly deeper on dry, light soils).
Seed rate (plant density)
The number of seeds sown should result in an optimal number of plants per m². Too low a density wastes field potential; too high causes competition between plants and weakens growth. Precision row seed drills that evenly distribute seed help prevent competition among seedlings.
High-quality seed material
Seed quality control is equally important—seeds should be clean, graded, and have high germination capacity. Seed treatments protect grain and seedlings against soil-borne diseases and pests, leading to faster, more uniform emergence and healthier young plants.
Types of seed drills: conventional vs no-till
Conventional cereal seed drills are designed for previously cultivated soil—they require a well-prepared, loosened field with minimal residue. Therefore, they usually lack components that actively cut crop residues before seed placement.
No-till seed drills, on the other hand, must handle sowing into uncultivated soil (direct drilling) or soil that is only lightly prepared and still partially covered with residues (reduced or ultra-shallow tillage).
They therefore feature:
- A cutting section ahead of the seed coulters that opens a narrow slit for seeds (e.g. a wavy or toothed disc coulter),
- Double disc seed coulters behind the cutting section that widen the slit and place the seed at the desired depth.
Important! Attempting to sow into stubble with a standard seed drill (without a cutting section) often results in clogged coulters or poor soil penetration.
Another structural difference lies in the coulters themselves—conventional drills use shoe or light disc coulters, while no-till drills use heavy-duty disc coulters with high downforce per row.
Mechanical vs pneumatic seeding systems
Two seeding technologies are commonly used: mechanical and pneumatic. Traditional mechanical seed drills meter seed gravitationally via fluted rollers. Pneumatic drills use overpressure or vacuum to transport seed, allowing more even distribution across large working widths and more precise dosing.
In terms of precision, pneumatic systems generally outperform mechanical ones, though they are structurally more complex and more expensive.
Can a conventional seed drill be used for no till farming?
Transitioning to no till farming usually requires investment in a modern, specialized no-till seed drill. If you already have a seed drill with disc coulters (even if it is not formally classified as a no-till drill, for example as part of a seedbed cultivator combination), you can try replacing ploughing with minimal tillage (e.g. shallow stubble disc cultivation). Such a simplified operation can be surprisingly effective: on one farm, cereals sown after shallow disc cultivation instead of ploughing emerged just as evenly as on a ploughed field, and oilseed rape emergence was visible after only two days (this was not the case with a shoe-coulter seed drill).
However, attempts to sow using a shoe-coulter seed drill under no-till conditions usually do not deliver satisfactory results. Certain upgrades can be considered, such as installing additional cutting discs ahead of the coulters (so-called pre-seeding coulters for cereal drills) or increasing section downforce. Ultimately, farms focused on permanent no-till sowing invest in modern direct seed drills, which ensure high sowing quality and reliability under more demanding field conditions.
A modern no-till seed drill is also available in the Rolmako product range.
Seed drill calibration and sowing quality control
Even the best equipment will not guarantee success without proper calibration and regular sowing quality checks. Seed drill calibration is the process of determining the actual seeding rate and adjusting machine settings so that the desired amount of seed per hectare is applied. In practice, this involves the so-called calibration test, which many experienced farmers consider the absolute foundation of proper seed drill preparation.
Planned seeding rate
The planned seeding rate is determined based on agronomic recommendations, seed parameters and personal experience. Most farmers rely on guidelines from research institutes (e.g. COBORU, IUNG) and seed producers, which provide recommended seeding rates for specific varieties and regions.
If you want to achieve a specific plant density and calculate the seeding rate yourself, you can use a standard formula based on:
TKW – thousand kernel weight; GR – germination rate, given in % (insert the numerical value only; for example, if GR is 90%, use “90”). This information can be found on the seed label.
Calibration test
The calibration test involves manually rotating the seeding mechanism (e.g. a drive wheel or gear) for a number of turns corresponding to sowing a defined area (for example 1 are). During this time, seed is collected in calibration trays, weighed, and the result is converted to kg/ha.
It is convenient to simulate sowing for an area of 1 are (100 m²).
After preparing the seed drill, mark a point on the wheel, perform the calculated number of rotations, weigh the seed and multiply the result by 100. If the outcome differs from the planned seeding rate by more than ±2%, adjust the gearbox and repeat the test until the correct value is achieved.
Calibration should be carried out for every batch of seed. Newer seed drills simplify this process with cranks or electronic systems, but the rule remains the same—check before entering the field. At the same time, it is worth verifying whether seeds are discharged evenly from all sections and whether the metering unit runs smoothly. A clearance gauge can help identify wear or blockages.
Control during sowing and before the season
During sowing, it is good practice to stop from time to time and check seed depth, coulter pressure, hopper condition and gearbox settings. After emergence, count plants per m² to assess whether the seeding rate was correct. In addition, before the season inspect the technical condition of the seed drill—especially coulters, discs, covering harrows and press wheels. Even minor faults can undermine an otherwise well-calibrated sowing operation.
Important! Regular calibration and inspections are simple yet effective ways to maintain high sowing quality on the farm and avoid unpleasant surprises such as bare patches or uneven crop emergence.
