Cotton Profitability with Alternative Lime Application Rates, Cover Crops, Nitrogen Rates, and Tillage Methods

Soil acidity and cotton ( Gossypium hirsutum L.) yield may be influenced by cover crop, N, and tillage method. Application of half the recommended lime rate may be possible without reducing lint yield and net revenue. The objective was to determine cotton yields and profitability for full and half recommended rates of lime, cover crops, N rates, and tillage methods. Data for 1995 through 2001 from a long‐term experiment on a Memphis silt loam (fine‐silty, mixed, active, thermic Typic Hapludalf) were used to estimate cotton lint yield response functions. The experimental design was a split‐split‐split randomized complete block with four replications. Plots were established in 1981 with four cover crop alternatives, four N rates, and two tillage methods. Soil pH declined until 1995 when plots were split into blocks and assigned a one‐time application of lime at the recommended rate and half the recommended rate. Results for no cover (unplanted winter cover) and winter wheat ( Triticum aestivum L.) and hairy vetch ( Vicia villosa L.) winter covers suggest that the amount of N fertilizer had a significant effect on lint yields, but was less important for the crimson clover cover ( Trifolium incarnatum L.). No‐tillage significantly increased cotton lint yields over time. When either the half or full rates of lime were applied, the plots combined with no‐tillage resulted in the highest net revenues. Cotton lint yields and net revenues for the half rate of lime were comparable or greater than the full rate of lime for both tillage methods and all cover alternatives. In the short‐to‐medium term, cotton farmers may be able to apply half the recommended rate of lime without reducing yield or net revenue.