Terminating a grass-clover ley without use of glyphosate and without increased nutrient leaching

Grass clover forage leys occupy almost half of Sweden's arable land. This perennial crop is  the agricultural crop that provides the greatest carbon storage in the soil, the least impact on eutrophication, and several important cropping system functions. As long as it is growing, nitrogen leaching is very low, but when the crop is terminated in the fall, large amounts of leachable nitrogen are released into the soil. Many farmers choose to use chemical treatment instead of repeated stubble cultivation to combat perennial weeds. This can contribute to reduced nitrogen leaching, enable more forage harvests, and reduce the need for fossil fuel. However, the dependence on and use of chemicals in agriculture must be reduced for several reasons.

A field trial at the Swedish Rural Economy Society's farm Lilla Böslid in Halland is investigating how different strategies for termination of forage ley, with and without glyphosate treatment, affect nutrient leaching, weed control, and the yield of subsequent winter wheat. The aim is to be able to provide concrete advice on how to manage glyphosate-free termination of ley without, or with limited impact on eutrophication of the aquatic environment. The experiment is located on a sandy soil, in a field with separately tile-drained  for leaching measurements. The ley was established in 2022 and ley termination was carried out on one half of the field in 2023 and on the other half in 2024.