Cover Crop Management and Nitrogen Rate in Relation to Growth and Yield of No‐Till Corn

Abstract Cover crop management in no‐tillage systems prior to planting the principal crop can be an important tool in maximizing the beneficial effects of the cover crop on the principal crop. A field experiment was conducted in 1984 and 1985 to examine timing effects of cover crop desiccation relative to corn planting [early desiccation/early plant (EE), early desiccation/late plant (EL), and late desiccation/ late plant (LL)] and fertilizer N (0, 100, and 200 kg ha−1) on corn growth and yield. These management schemes were evaluated for fallow, rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), and hairy vetch (Vicia villosa Roth.) cover crop systems. Corn dry matter production and N uptake, monitored in all 0 kg N ha−1 treatments, were significantly affected by cover crop management and varied according to stage of development and climatic conditions. Cover crop type had a pronounced effect on corn growth, with corn dry matter production in a rye cover crop lower than in legume cover crops. Grain yield response to applied N was greatest in a rye cover crop system. In contrast, a grain yield response up to the first increment of fertilizer N (100 kg ha−1) in legume cover crop systems was observed only in 1984. Corn recovery of legume N was estimated at 40 to 45 kg N ha−1 (2‐yr avg.), representing approximately 36 and 30% of the total N content of crimson clover and hairy vetch, respectively. These data indicate that winter annual legume cover crops are capable of providing a substantial portion of the N required by corn. Additionally, cover crop management should insure that corn planting is not delayed to allow for additional legume growth and N production.