Abstract
The rate of P release from two Jamaican bauxitic soils to an anion exchange resin (Dowex 1X4) was investigated. On both oil given or not given a dressing of phosphate the rate and quantity of P released by Chudleigh clay loam (brown bauxite) was much greater than that by St Ann clay loam (red bauxite). In spite of the two soils having very similar mineralogy the phosphate held in the Chudleigh is much more readily available (as measured by Truog's and Olsen's methods) and it is suggested that phosphate occupies sites of differing P affinity in the two soils. The response of maize plants to phosphate fertilizer on the two soil supported the laboratory observations as did the measurement of the labile pool of phosphate denoted by their L values. Different phosphate fertilizer practices for the two oils are suggested on the basis of these findings.