When applicating 140 kg/ha, of net nitrogen in Lessive Typic paddy soil, the best effectiveness of successive application of phosphate fertilizer for 3 years was obtianed with a proportion of 0.5: 1 of p₂o₅ to N, followed by a 0.25:1 proportion of p₂o₅to N. An acucmulasted rates of availible phosphate in the soil was 9%, 36.3% and 77.7% from applic ting fertilizers with the 1:0.5, 1:0.25 and 1:1 proportions of N to p₂o₅, respectively of the inorganic phosphate form, the AI-p was increased most, followed by the Ca-P.
After cultivation of rice one year, the aboslute amount of Fe-p was reduced at the largest level, followed by O-P and Ae-P; and the least reduced one was Ca-P.