Matt Rhine1, Gene Stevens1, and David Dunn2. (1) University of Missouri-Delta Center, P.O. Box 160, Portageville, MO 63783, (2) University of Missouri, P.O. Box 160, Portageville, MO 63873
University of Missouri (MU) soil test laboratory recommendations for K fertilizer are based on three components: target level, crop removal, and buildup. Target level is the amount of extractable nutrient found in a soil at which point applying more fertilizer containing the nutrient will probably not increase crop yields. Crop removal is how much the nutrient is reduced in the soil annually from harvested fiber. Buildup is the additional fertilizer needed above crop removal to increase low and medium K testing soil into the optimum fertility levels for crop production. Cotton producers may choose the number of years over which the build up will occur. In this evaluation different build up periods for K were compared on a sandy soil.
