Undersowing leys in cereals (SolACE Practice abstract)

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