Irrigation and Tillage of Cotton in a Corn/Cotton Rotation

A cotton cropping system involving an annual corn-cotton rotation is becoming commonplace in the southeastern United States, and incorporation of conservation-tillage practices is increasing.  A five-year research study was undertaken to evaluate the yield of cotton in a corn-cotton rotation under two tillage treatments, conventional and minimum/conservation, and two irrigation treatments, irrigated and non-irrigated.  Average yields were slightly higher under conventional-tillage conditions, but differences between the conventional- and minimum-tillage treatments amounted to only 6%.  While minimum-tillage production may not have increased yields, the difference in yields was minimal.  This could affect profitability by decreasing input labor and cost without a significant decrease in yield.  The study also pointed to the importance of taking soil type into account when analyzing treatment results.  Highly variable soils, and resulting agronomic differences independent of imposed treatments, could significantly affect treatment outcomes, resulting in misleading interpretations.