About the cultivation of rapeseed and the importance of soil preparation for a successful germination of the plant.
This article provides guidance on managing residues from the previous crop, soil preparation techniques and creating optimal seedbed conditions to ensure uniform and rapid crop emergence.
In addition, potential problems related to excessive soil compaction and the choice of tillage methods are discussed. Essentially, it provides technical guidance for successful oilseed rape cultivation.
Preparing the seedbed for planting oilseed rape is crucial to the success of the crop. Creating optimal conditions for the seedbed means ensuring that there are no lumps or too fine particles in the soil, protecting soil moisture and avoiding soil compaction.
Soil tillage.
Depending on soil conditions and previous crops, the following tillage methods can be chosen:
Traditional tillage.
This involves a medium-depth ploughing (20-25 centimetres), followed by a harrowing to effectively loosen the soil. This type of tillage is the preferred solution for harder soils and when there are large amounts of crop residues.
Minimum tillage.
This option involves the use of a disc to a depth of about 25 centimetres or, if the soil is friable and well structured at depth, a shallow tillage using only discs to a depth of about 15 centimetres.
Direct sowing.
Given the critical problems encountered during the sprouting phase, particularly in the presence of a shallow layer of residue from the previous crop, this solution needs to be considered carefully and should only be reserved for soils that tend to be loose, well-structured, in contexts where this practice is established. Experience to date advises against adopting this technique on oilseed rape.
To ensure proper sprouting of oilseed rape, the residues of the previous crop must be treated. Shredding of cereal stubble and fine chopping of straw, ensuring that the straw is less than 5 cm long, is recommended. In addition, it is important that the chopped straw is evenly distributed over the entire working width and that mixing of residues in the topsoil is avoided. These operations will help to create optimal conditions for the seedbed.
To ensure optimal conditions for the seedbed, it is advisable to follow certain operational instructions:
- Make sure the soil is well loosened, making sure there are no lumps or grains that are too fine.
- Tillage must protect the moisture present in the soil, as ‘dry soil’ conditions at sowing are a major problem for seedling emergence.
- In order for the taproot to deepen, soil compaction conditions must be avoided.
- If the soil is too soft at sowing time, consider rolling it.
- Cultivation techniques should aim to reduce surface crusting.