he amount of phosphorus reserved in soil in the Haihe River basin is estimated at 6.6210¹⁰kg,based on a computation of the analytical results for all the species of phosphoruspresent in soil. The input of phosphorus is 4.2410⁸kg/a which was calculated from the con-tributions of earth-forming parent material . human and animal wastes applied as manure ,chemical fertilizers , surface runoff, air dust deposition and plant residues ,to the phosphorusin soil. And the output of phosphorus is 3.6610⁸kg/a...