Effects of Recent and Past Phosphate Fertilization on the Amount of Phosphorus Percolating Through Soil Profiles into Subsurface Waters.

摘要

The distribution of phosphorus in a unfertilized and fertilized Mexico soil was measured. After 82years of phosphate fertilization the added phosphate was found in Ap (0-9inch),smaller amounts in the A and B and B2 (9-34inch),and large amounts in the B3and C1 (34-54inch) soil horizons. No added phosphate was found below 54inches. The data indicated that the distribution of added phosphorus was similar to that of the original phosphorus in the soil profile. The phosphorus adsorption capacities of fertilized and unfertilized soils were similar. These data indicate that 82years of phosphorus fertilization nearly doubled total phosphate,but did not change the ability of the soil to adsorb additional phosphate. Solubility studies indicated that phosphate levels in the soil solution were controlled by the solubility of strengite. Apparently those factors which influence the solubility of iron phosphates will control the solubility and movement of phosphate in the Mixico soil. (Author)