Effect of winter cover crops on water soil storage, total forage production, and quality of silage corn

Abstract

Cover crops provide a wide range of benefits to farms and the environment, but this is not reflected in current adoption rates of cover cropping. If cover crops are grown for forage they may raise more interest among farmers whether as feed or as income. The objective of this study was to evaluate if introducing annual winter cover crops will contribute to the yield and quality of annual forage production and will affect soil water content. The experiment included common vetch (Vicia sativa L.), triticale (x Triticosecale Wittm. ex A. Camus) and their mixture as winter forage cover crops, fallow with nitrogen fertilization, and control plot (fallow without fertilization). The main crop was silage corn. A 2-year study was performed at three locations in northern Serbia. The following indices were calculated: forage productivity index (FP) as a ratio between cover crop and silage corn dry matter yield, forage cover crop yield advantage index (FCCYa) as a ratio between total forage yield on cover crop or fertilization treatment and control plot, and forage cover crop protein advantage index (FCCPa) as a ratio between total protein yield on cover crop or fertilization treatment and control plot. The total forage yield in 2012/2013 was higher due to more favorable weather conditions. FP was the highest on treatment with triticale in the first year and on the mixture in the second year. FCCYa was above 1, and higher on cover crop treatments in two locations. Introducing forage cover crops in crop rotation with silage corn showed an advantage in protein yield with all cover crop species, resulting in FCCPa above 1. Forage production at a location with lower FCCYa should be more focused on yield-quality balance. In contrast, in a temperate region in some years annual winter cover crops have a potential negative impact on available soil water storage for cash crop production compared to fallow-corn systems. Results indicate that cover crops impact the annual total forage yield and soil water content, but this alternation is not a species-specific effect. In the region with recurrent drought, forage yield uncertainty may be lessened by winter cover crops which enable reduced dependence on the main forage crop production.