耕作对水稻土磷素的影响研究

稻田垄作，土壤有效磷和有机磷含量降低，闭蓄态磷（ｒ－Ｐ）提高，水稻吸磷量不变。垄作水稻可以利用Ｆｅ－Ｐ、Ａｌ－Ｐ、Ｃａ－Ｐ和ｒ－Ｐ，常规耕作水稻仅利用Ｃａ－Ｐ、Ａｌ－Ｐ和Ｆｅ－Ｐ。

EFFECTS OF TILLAGE ON P STATUS IN FADDY SOILS

In the present study,available P and organic P in ridge-tilled paddy soils were found todecrease,reduced P(r-P) to increase while the uptake of P by the rice plants did not change ascompared with the control where traditional tillage was practiced.The rice plants in traditionallytilled paddy soils utilized mainly Fe-P,Ca-P and Al-P,while in ridged-tilled paddy soils they wereable to take up all forms of inorganic P,such as Al-P,Fe-P,Ca-P well as as r-P, which kept highamount of P absorption under low available P conditions.