Economics of winter cover crops as a source of nitrogen for no-till corn

Abstract

ABSTRACT: Winter legume cover crops can be chemically killed and used as a mulch for no-till corn, supplying part of the corn9s N requirement while also providing the usual advantages associated with a mulch. Hairy vetch (Vicia villosa Roth), big flower vetch (Vicia grandiflora W. Koch var. Kitailbeliana), crimson clover (Trifolium incarnatum L.), rye (Secale cereale L.), and corn (Zea mays L.) residue, each in combination with three levels of fertilizer N, were compared as sources of N for no-till corn. The combination of hairy vetch and 100 kg ha−1 of fertilizer N consistently gave highest grain yields and economic returns, fields with this treatment increased relative to the other treatments during the 5-year experiment, indicating increased soil productivity. Soil erosion was controlled within tolerance limits, based on universal soil loss equation estimates. No legume by itself provided adequate N for the corn. A combination of an adapted legume cover crop and N fertilizer in a no-till system offers a way to control soil erosion with corn production on sloping soils in the Southeast while maintaining or increasing yields, income, and soil productivity.