磷肥在土中的形态转化及其对土壤有效磷的影响

MORPHOLOGICAL TRANSFORMATION OF PHOSPHORUS FERTIL1ZER IN LOUTU SOIL AND EFFECT OF IT ON SOIL EFFECTIVE PHOSPHOTE

１０年定位试验研究结果表明，在长期施磷的条件下，陕西土耕层的磷素形态分布与该土壤性质一致。有机磷、无机磷在全磷中所占比例相对稳定，Ｃａ－Ｐ仍是无机磷的主要形态。３组Ｃａ－Ｐ的含量顺序是Ｃａ－Ｐ＿Ⅲ＞Ｃａ－ｐ＿Ⅱ＞Ｃａ－＿Ⅰ。Ａｌ－Ｐ含量增长较多，Ｆｅ－Ｐ含量相对稳定。１０年中施入土壤的磷素有４１．６％在耕层中转化为各种形态的矿质磷，其中Ａｌ－Ｐ、Ｃａ－Ｐ＿Ⅰ及Ｃａ－Ｐ＿Ⅱ的含量都与土壤有效磷含量呈极显著的相关关系。同时，有机磷含量与土壤有效磷也有显著的相关关系。化学磷肥是提供作物磷素营养、维持上壤磷素平衡的主要磷源。

The tests showed that there was uniformity between morphological distribution of phosphorus in loutu soil and this soil property under conditions of application phosphorus fertilizer in ten years,The proportion between organic and inorganic phosphorus in all phosphorus was stable,Ca-P was main distribution of inorganie phosphorus. The contents among those Ca-Pwere Ca-P_Ⅲ>Ca-P_Ⅱ>Ca-P_Ⅰ.Al-P content has increased quite greatly. Fe-P content was stable.41.5 per cent of application phosphorus in ten years has been transferred into variant morphological inorganic phosphorus,The contents of Al-P、 Ca-P_Ⅰand Ca-P_Ⅱwere siginficantly related to content of effective phosphorus in soil. The content of organic phosphorus were significantly related to content of effective phosphorus of soil too. Chemical phosphate fertillizer was main source for plant phosphorus nutrition and balance of soil phosphorus.