论文部分内容阅读
本研究应用分级提取法测定了水溶性标记磷在水田和旱田条件下的扬州砂壤土中，吸附态磷和固定态磷（包括Ａｌ－Ｐ、Ｆｅ－Ｐ和Ｃａ－Ｐ）含量随时间的变化动态，结果表明：（１）吸附态磷和Ａｌ－Ｐ含量随时间的推移首先迅速上升并在几天内达到高峰，然后逐步下降，而Ｆｅ－Ｐ、Ｏ－Ｐ及Ｃａ－Ｐ则一直处于上升趋势，但上升的幅度随时间的推移而逐步减小。（２）在同一耕作条件下，吸附态Ｐ和Ａｌ－Ｐ含量一般高于Ｆｅ－Ｐ、Ｏ－Ｐ的含量，且Ｃａ－Ｐ的含量很小。本研究还应用对土壤中标记磷的连续提取示踪动力学分析法，定量研究了吸附态标记磷和固定态标记磷在提取剂中的溶解度随时间的变化动态。结果表明，（１）随时间的推移，吸附态和固定态磷的溶解度均逐步下降。（２）在旱田条件下，吸附态标记磷的解吸速度在单位时间内的平均下降幅度大于水田条件，而固定态磷的溶解度在单位时间内的平均下降幅度略低于水田条件
In this study, graded extraction method was used to determine the changes of the content of adsorbed phosphorus and fixed phosphorus (including Al-P, Fe-P and Ca-P) in the sandy loam soil of Yangzhou under paddy field and upland conditions The results showed that: (1) The content of adsorbed phosphorus and Al-P firstly increased rapidly with the passage of time and peaked within a few days, then decreased gradually while Fe-P, O-P and Ca-P remained at Rising trend, but the rate of increase gradually decreases over time. (2) Under the same tillage conditions, the content of P and Al-P in adsorbed state is generally higher than that of Fe-P and O-P, and the content of Ca-P is small. In this study, continuous extraction trace kinetic analysis of labeled phosphorus in soil was also used to quantitatively study the dynamic changes of the solubility of labeled phosphorus and fixed-labeled phosphorus in the extractant over time. The results show that: (1) With the passage of time, the solubilities of adsorbed and fixed phosphorus decreased gradually. (2) The desorption rate of adsorbed phosphorus in unit time was lower than that in paddy field under the condition of dry land, and the average decrease of the solubility of fixed state phosphorus in unit time was slightly lower than that under paddy field