NUTRIENT ABSORPTION CHARACTERISTICS OF RESIN CAPSULES FOR THE PHOTOAVAILABILITY SOIL TEST (PST) IN 4 ARKANSAS SOILS

Mixed-bed resin capsules were placed in four Arkansas soils in a ferti lizer rate study utilizing greenhouse pots. The capsules were removed at 2, 10, 21, and 35 days. The nutrient content of both the capsules a nd soybean shoots were determined. Generally for each soil significant differences in plant nutrient content occurred due to both time (T) a nd phosphorus (P) and potassium (K) fertilizer rate (R) but not due to the T x R interaction. The resin content of the major- and micronutri ents increased as time of soil contact increased. However the fertiliz er rate increase did not increase the resin content of the micronutrie nts with time but did affect the resin content of the major nutrients with time. Statistical analyses indicated significant but negative val ues for P and sulfur (S) when correlating resin content with final pla nt update data. While there were positive values for the major cations the values were usually below 0.50 when correlating resin content wit h final plant update.