Biological immobilization of fertilizer phosphorus

Summary Comparable uncultivated and cultivated Coastal Plain soils of New Jersey were analyzed for total inorganic and total organic soil P. Inorganic P was found to be greatly increased as a result of intensive fertilization. Organic P increased in most soil series examined, and up to 30 per cent of gains in total P in cultivated soils could be accounted for as increases in soil organic P. C: organic-P ratios in uncultivated soils were much higher than those usually encountered in soils containing humified organic matter. Cultivation has led to a considerable lowering of these ratios, as a result of decreases in organic-C contents and increases in organic-P contents.Paper of the Journal Series, New Jersey Agricultural Experiment Station, Rutgers University. The author is now with the Agricultural State University, Wageningen, Netherlands