长期施肥对太湖地区水稻土磷素转化的影响

对江苏常熟生态站长期施肥条件下的水稻土进行了磷素转化的研究.结果表明,不同施肥处理的土壤全磷(T-P)含量为926~934mgkg-1,只有对照(CK)比本底值下降0.49%,其它施肥处理的T-P含量都比本底值增加14.24%~28.0%,增幅最大的是半数秸秆 磷肥(1/2OM NPK)处理(28.0%),增幅最小的是NPK(氮磷钾)处理(14.24%).增幅最大的1/2OM NPK处理的T-P含量比CK增加28.0%,年平均增加2.9%;增幅最小的NPK处理的T-P含量比CK增加14.8%,年平均增加1.5%.有机磷(Po)占全磷(T-P)的比值小于无机磷(Pi)占全磷的比值,即:Po/T-P(15%~23%)O-P(143~101)>Fe-P(103~54)>Al-P(65~29)>Ca8-P(45~18)>Ca2-P(22~3);1/2OM NPK处理能增加水稻田土壤中的Al-P和Fe-P含量,而施用NPK肥有利于水稻对Al-P和Fe-P的吸收,因为NPK处理的土壤中Al-P和Fe-P含量只比CK大而比其它处理低;施磷肥会增加水稻土中O-P的含量.图3表3参23

Effect of Long-Term Fertilization on Phosphorus Transformation in Paddy Soil in the Taihu Lake Region

The effect of long-term fertilization on phosphorus transformation in paddy soil was studied in the Changshu Ecological Station in the Taihu Lake region, Jiangsu. The results showed that the total P (T-P) was 926~934 mg kg~ -1 . Only the T-P amount of CK was decreased by 0.49% compared to the background value, and the amounts of the others were increased by 14.24 %~28.0%. The largest increment was 28.0% obtained from 1/2OM(Organic fertilizer) NPK treatment, which was increased by 2.9% more than that of CK, and the smallest one was 14.8% from NPK treatment, increased by 1.5% compared to CK. The specific value of Po(organic-P)/T-P was smaller than that of Pi(Inorganic-P)/T-P. Po/T-P treatments were decreased by 0.82%~6.86% compared to CK, except that the NPK treatment was increased by 0.47%. The content (w/mg kg~ -1 ) of each fractionations of inorganic phosphorus was in the same order of all fertilization treatments: Ca_ 10 -P (425~360)>O-P (143~101)>Fe-P (103~54)>Al-P (65~29)>Ca_ 8 -P (45~18)>Ca_ 2 -P (22~3); the contents of Al-P and Fe-P were increased when 1/2OM NPK was applied to paddy field. It was beneficial for rice absorption of Al-P and Fe-P when the NPK was applied to paddy field. The content of O-P was increased when phosphorus fertilizer was applied to paddy field. Fig 3, Tab 3, Ref 23