THE ROLE OF ROTATIONS IN COTTON PRODUCTION: COMPARISONS OF CONTINUOUSCOTTON WITH TWO-YEAR ROTATIONS AND THREE CROPS IN TWO YEARS

摘要

Crop rotations often increase the yields of the rotated crops, an effect which may be more pronounced when yields are limitedby specific problems that are affected by the cropping sequences. Profitability of rotations versus continuous monocroppingis determined by the magnitude of crop responses and, perhaps more importantly, by commodity prices of the includedcrops. The objective of this study was to compare continuous mono-crop cotton with selected rotations to determine ifrotations increased yields and profitability. Rotation-crop sequence studies from four locations were analyzed for both yieldbenefits and for economic benefits (net returns above variable costs). Rotation sequences included cotton, corn, soybean,grain sorghum and double-crop wheat in two and three-year cycles. In all studies, cotton lint yields were higher in rotationsthan in continuous mono-cropping. Yield increases ranged from 10 percent to 30 percent. Cotton yield increases were not affectedby the choice of alternative crop. Corn, grain sorghum and soybean all provided similar yield benefits to cotton yield.Yield increases did not always result in increases in annual net returns per acre because alternative crops were usually lessprofitable than cotton. Long-term yield increases and economic benefits were larger than initial yield and economic benefits,emphasizing the importance of long-term productivity goals. Double-crop cotton following wheat had lower yields thanmono-crop cotton. Returns above variable costs, however, were higher for the cotton-wheat double-crop system. We concludethat rotations of cotton with corn, soybean or grain sorghum will increase cotton yield and will usually also increaseprofitability.