Response of an Al‐Tolerant and an Al‐Sensitive Genotype to Lime, P, and K on Three Atlantic Coast Flatwoods Soils1

Aluminum toxicity, calcium deficiency, and a complex of other unidentified factors contribute to the poor productivity of Atlantic Coast Flatwoods soils that occupy more than 100,000 km2in the southern U.S. Our objective was to investigate the response of aluminum‐sensitive ‘Suregrain’ oats (Avena sativaL.) and aluminum‐tolerant ‘Starr’ pearl millet [Pennisetum typhoides(Burm. f)] lime, phosphorus, and potassium on Bladen, Leon, and Lakeland soils. Results of a series of pot experiments using four or more rates each of dolomitic limestone, monocalcium phosphate, and potassium chloride were used to calculate response surfaces and yield isoquants. Eightytwo to ninety‐five percent of the variation in yield was explained by lime, P, and K variables. Phosphorus was the most critical growth‐limiting factor for plant growth and response to P depended on lime and K levels.