白浆型水稻土磷肥连施效果和无机磷形态变化

据本项研究,缺磷白浆型水稻土的公顷纯氮施用量为140公斤时,三年连施磷肥的效果最好的N、P_2O_5比例是1:0.5,其次是1:0.25,三年累积土壤速效磷增长率为N、P_2O_5比1:0.25的9%、1:0.5的36.3%、1:1的77.2%,在不同形态无机磷中增长幅度最大的是铝磷,其次是钙磷。不施磷肥种稻一年后,在土壤中的绝对减少量最多的是Fe—P,其次是O—P和Al—P,最少的是Ca—P。

THE EFFECTIVENESS OF SUCCESSIVE APPLICATION OF PHOSPHATE FERTILIZER AND THE CHANGE OF INORGANIC PHOAPHASTE FORM IN THE LESSIVE TYPIC PADDY SOIL

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 p_2o_5 to N, followed by a 0.25:1 proportion of p_2o_5to 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 p_2o_5, 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.