Cotton Available Potassium in Balckbelt Soils.

Potassium is one of the most important essential nutrients for cotton production. Potassium is involved in many enzymatic actions, physiological development and yield of cotton. The Blackbelt (prarie) soils, that extend from Alabama to Texas have high clay and inherent high potassium contents. These soils have vertic characteristics that are difficult to manage under dry and wet conditions since traditional soil test methods may not especially predict cotton available potassium accurately.  We applied 0, 20, 40, 60, 80 and 100 K₂O (lbs/A), and measured soil and cotton leaf potassium contents during cotton growth, and cotton lint yield.  In general, potassium tissue concentration increased as K₂O rates increased, and the absolute values decreased with time after cotton bloomed.  The cotton leaf potassium contents were below the sufficiency range for cotton in contrast to the available soil potassium that was medium, high or very high. Potassium chemistry and climatic conditions do play significant roles in managing cotton potassium nutrient in Blackbelt soils. Potassium is one of the most important essential nutrients for cotton production. Potassium is involved in many enzymatic actions, physiological development and yield of cotton. The Blackbelt (prarie) soils, that extend from Alabama to Texas have high clay and inherent high potassium contents. These soils have vertic characteristics that are difficult to manage under dry and wet conditions since traditional soil test methods may not especially predict cotton available potassium accurately.  We applied 0, 20, 40, 60, 80 and 100 K₂O (lbs/A), and measured soil and cotton leaf potassium contents during cotton growth, and cotton lint yield.  In general, potassium tissue concentration increased as K₂O rates increased, and the absolute values decreased with time after cotton bloomed.  The cotton leaf potassium contents were below the sufficiency range for cotton in contrast to the available soil potassium that was medium, high or very high. Potassium chemistry and climatic conditions do play significant roles in managing cotton potassium nutrient in Blackbelt soils.