Residual effects of green manure legumes on organic seed of Festuca pratensis

摘要

Experiments were designed to study the effects of six legume species ploughed in as green manure on the seed yield of meadow fescue (Festuca pratensis). Eegumes were undersown into barley. In the first year of use, legumes were chopped and ploughed infor green manure in June. The sown meadow fescue was used for seed for three years. Trifolium resupinatum grew luxuriantly in the year of sowing, however, it completely disappeared after winter. The dry matter yield of the above-ground part of herbage ranged from 1.541 ha~(-1) (Galega orientalis) to 7.481 ha~(-1) (Medicago sativa). The greatest amount of roots (5.23 t ha~(-1)) in the plough layer was left by Trifolium repens. Depending on the legume species before ploughing in, the content of nitrogenaccumulated in the above-ground parts and roots was 117-286 kg ha~(-1), phosphorus 10-23 kg ha~(-1), and potassium 47-152 kg ha~(-1). According to the data averaged over three years of use, the highest meadow fescue seed yield was obtained from having ploughed in a mixture of the three legumes (T. pratensis + M. sativa + T. repens). Having ploughed in legumes, the positive effect on meadow fescue seed yield was more substantial in the second and third years of use.