Exchangeable Aluminum As a Criterion for Liming Leached Mineral Soils

Abstract Lime rates equivalent to the amount of exchangeable Al reacted primarily with the exchangeable Al and reduced the Al saturation of the effective CEC to less than 30%. Lime rates greater than the equivalent amount of exchangeable Al resulted in appreciable amounts of nonexcharigeable acidity being neutralized. Below pH 5.4 the buffer capacity of the soils was primarily due to exchangeable Al. Lime applications based on the exchangeable Al extracted with a neutral unbuffered salt appear to be a realistic approach for Ultisols and Oxisols.