热带胶园土壤磷素形态和生物有效性

采用Hedley的磷素分级方法研究热带胶园土壤磷的形态，结果表明、热带胶园土壤磷主要以ResidualP、NaOH－Po和NaOH－Pi形态存在；各种形态磷的损失质量分数均高于38％；其中ResidualP和NaOH－Po的损失量最高，分别占全磷损失量的52％和16％，它们是长期耕作条件下热带胶园土壤磷两种最重要的有效磷源。

Phosphorus Fractions andAvailability of Tropical Soil in Rubber Plantation

Changes in inorganic and organic phosphorus fractions resulting from 34 years of cropping in a pure rubber rotation were studied by using a sequential extraction method. Residual P, NaOH-Po and NaOH-Pi were the three main phosphorus tYactions. The loss of fraction was 38% higher than that of the rain forest respectively. The major loss was residual P and organic P Of the total lost, 52% was tYom residual P, whereas 16% originated from NaOH-po, Residual P and NaOH-Po, were the two most important resources of phosphorus in the rubber plantation tbr long term cultivation.