Undersowing leys in cereals (SolACE Practice abstract)

Summary

Advantages
- Higher yields in grass-clover leys due to earlier development
- Better establishment in dry summers
- Seamless transition from cereals to grass-clover ley without ploughing or other soil tillage.
- A few weeks after cereal harvest the fully-grown ley can be used for cutting or grazing.
- Rather good suppression of annual weeds
Disadvantages
- Presence of perennial weeds, such as docks, is increased due to a lack of stubble cultivation.
- Mechanical weed control is no longer possible.
- It is not possible to restore the soil once it has been compacted by the harvester.
- Uneven establishment of grass-clover leys due to soil
compaction from heavy harvesters
Practical recommendation
- The ley is undersown in spring (March/April), between tillering and bolting of the cereal (preferably be-fore a wet period, as the crop cannot be rolled).
- The ley is best sown with a seeder for grass-clover, in combination with a harrow passage.
- Several clover mixtures are possible; farms without livestock may also use only white or red clover.
Remarks and advice
- The denser and higher the cereal crop, the less likely the undersown ley will succeed (due to shading).
- The success of a ley depends greatly on the choice of cereal variety and the yield expectations: Varieties with - more planophile (horizontal) leaf position are better at suppressing weeds; however, this can suppress ley growth due to light limitations.
- Varieties with erectophile leaf positions are better suited (but they also promote weed growth).
- Long-stem plants create more shade for weeds and but also may suppress the ley compared to middle- or short-stem varieties.
- If weeds that spread by roots or rhizomes such as docks or common couch are present, undersowing is not recommended.
- Sow in early spring
Practical testing
- If this method seems to be suitable for your farm, we recommend that you test it under your own farm conditions as follows:
1. When sowing the cereal, delimit a part of the field for testing.
2. Apply the new method on one of the two plots. The other plot can be cultivated as usual to compare.