pH值和碳酸钙对不同形态磷酸盐有效性的影响

本文研究结果，在培养液为ｐＨ６．５，７．５，８．５条件下，Ｃａ２－Ｐ，Ｃａ８－Ｐ和Ｃａ１０－Ｐ处理均随溶液ｐＨ值降低其速效磷含量增加，而Ｆｅ－Ｐ和Ａｌ－Ｐ则随溶液ｐＨ值降低而减少，加入ＣａＣＯ３，各形态磷酸盐有效性明显降低，且ｐＨ值越低下降幅度越大，小麦幼苗对各形态磷酸盐的吸收量均随溶液ｐＨ值降低而增加，当ＣａＣＯ３存在时，小麦幼苗对磷的吸收明显降低，随溶液ｐＨ值的升高，加ＣａＣＯ３与不加处理间差

Effect of pH and CaCO_3 on Availability of Phosphate in Different Forms

The study results showed that under the conditions of pH 6.5,7.5 and 8.5, the content of rapidly available phosphorus increased with the drop of pH value of solutions whentreated with Ca2 - P,Ca8 - P and Ca10 - P; the content decreased with drop of pH value of solutions when treated with Fe - P and Al - P; when CaCO3 was added, the availability of all phosphate forms significantly reduced; and the less the pH value is, the more markedly the availability reduced. Uptake rate of all phosphate form by wheat seedling increased with drop of PH value of solutions. When there existed CaCO3 , the uptake rate of phospohorus by wheat seedling significantly reduced, but with increase of pH value of solutions, the difference between the two treatments(With CaCO3 and without CaCO3 )in uptake rate of phosphorus got less and less. Under the conditions of pH 5. 5,6. 5,7. 5 and 8. 5, the effects of pH value on the availability of phosphate in calcareous Chao soil appeard greater than that in non-calcareous Chao soil.