Tillage and Cover Crop Impacts on Economics of Cotton Production in Tennessee

Abstract

Core Ideas Net returns were higher for conventional tillage than no‐tillage without cover crops. Net returns were higher for no‐tillage than conventional tillage with cover crops. A cotton producer would maximize profits by not planting cover crops. The objective of this study was to evaluate the long‐term effects of winter cover crops with and without tillage on profit‐maximizing N fertilization rate and net return for upland cotton (Gossypium hirsutum L.) production. Data came from a 29‐yr (1984–2012) cotton experiment located in Jackson, TN. The experiment included four cover crop treatments (no cover, winter wheat [Triticum aestivum L.], hairy vetch [Vicia villosa L.], and crimson clover [Trifolium incarnatum L.]); two tillage systems (no‐tillage [NT] and conventional tillage [CT]), and four N fertilizer rates (0, 34, 67, or 101 kg N ha−1). Lint yield was de‐trended for temporal yield variation and quadratic yield response functions to N fertilizer were estimated for each cover crop and tillage system. Partial budgeting was used to determine the profit‐maximizing N rate and yields for each cover crop and tillage combinations under different cotton and N price scenarios. The highest profit‐maximizing N fertilizer rate savings, relative to no cover, under CT and NT were for cotton after clover, followed by cotton after hairy vetch and then cotton after wheat. Maximum net returns for cotton after hairy vetch, cotton after crimson clover, and cotton after wheat were lower than for cotton with no cover under CT and NT systems. The results show that revenue gains from producing cotton following cover crops did not offset the cost of cover establishment compared to cotton following no cover. A cotton producer would maximize profits by not planting cover crops under various price scenarios.