Screening Five Fall-Sown Cover Crops for Use in Organic No-Till Crop Production in the Upper Midwest

摘要

Organic no-till systems continue to draw interest from organic producers across the upper Midwest in the United States. Fall-planted cover crops, terminated in the spring through the use of a roller-crimper or a mower, are a key component of these systems. In this study, five different cover crops (hairy vetch, Austrian winter peas, winter rye, winter barley, and winter triticale) were planted in the fall and terminated in the spring in preparation for no-till organic row crop production. This study compared the cover crops through measurements of: a) the amount of biomass produced by the cover crops before termination; b) the weed suppression potential of the cover crops terminated with either a roller-crimper or sickle-bar mower; and c) volumetric soil water content throughout the row crop production season. Biomass production of each of the cover crops differed significantly by variety and by year, ranging from 3.67 to 14.56 Mg DM ha(-1). Significant differences in weed densities and weed biomass were also found, with almost complete elimination of weed establishment in the rye treatment in 2011. Roll-crimping and sickle-bar mowing treatments demonstrated similar weed suppression and soil moisture from May through October during 2010 and 2011.