Winter-Hardy Vs. Freeze-Killed Cover Crop Mixtures Before Maize On An Organic Farm With Reduced Soil Cultivation

Summary

The advantages and disadvantages of a winter-hardy vs. a freeze-killed cover crop (CC) mixture were studied on an organic farm in Lower Austria in two consecutive experiments. Effects on soil inorganic nitrogen contents, weed density and the yield of a following maize crop were assessed. The winter-hardy compared to freeze-killed CC mixture, both consisting of legumes and non-legumes, reduced soil nitrate contents over winter, leading to a reduced nitrate leaching risk, whereas the yield of a following grain maize crop was not significantly affected. Weed density was high in both CC treatments, presumably due to a reduced, non-inverting soil cultivation before maize, and higher in the winter-hardy CC treatment at one of the assessment dates. Combined with an adapted soil cultivation, both winter-hardy and freeze-killed CC mixtures were suitable CCs before grain maize.