PROFITABILITY OF NO-TILLAGE CORN FOLLOWING A HAIRY VETCH COVER CROP

Hairy vetch (Vicia villosa Roth subsp. villosa), as a winter legume cover crop, fixes atmospheric N2 for following crops and improves the soil. A 3-yr field study (1985-1988) was conducted in the Maryland Coastal Plain and Piedmont to assess the agronomic and economic characteristics of a hairy vetch cover crop on no-till corn (Zea mays L.) compared with corn systems preceded by winter fallow and winter wheat (Triticum aestivum L.) cover crops. No-till corn following a hairy vetch cover crop yielded more than no-till corn following winter fallow and winter wheat cover crops at comparable fertilizer N rates in the Coastal Plain and Piedmont over 3 yr. The highest yielding combinations were a hairy vetch cover crop with 120 lb N/acre in the Coastal Plain and a hairy vetch cover crop with 40 lb N/acre in the Piedmont. The most profitable combinations were a hairy vetch crop with 120 lb N/acre in the Coastal Plain and a winter fallow with 40 lb N/acre in the Piedmont. For risk averse farmers, a hairy vetch cover system was the most desirable choice at both locations. Using profit maximizing criteria to select optimum N rates, hairy vetch is more accurately a yield of enhancer for no-till corn than a N substitute. Breakeven costs for hairy vetch seed and fertilizer N were estimated by comparing the ''best'' hairy vetch system with the ''best'' winter wheat system under different scenarios at both locations. No-till corn following a hairy vetch cover maintained its economic advantage over no-till corn following winter wheat even when the price of hairy vetch seed was increased, the price of fertilizer N was decreased, and the average net returns of the hairy vetch system reduced by $10/acre to reflect a future herbicide application to kill volunteer hairy vetch.