滇中云南松根际土与非根际土磷的有效性

Availablibity in Rhizosphere and Non-rhizosphere Soil P of Pinus yunnanensis Forest in Central Yunnan

测定云南松根际土和非根际土的全磷、有机磷、有效磷、pH值、酸性、中性、碱性磷酸酶活性.结果表明:根际土与非根际土之间的全磷和有机磷含量差异不显著,而有效磷含量差异极显著.根际土pH值极显著地低于非根际的.酸性、中性磷酸酶活性占总酶量的比例较大,碱性磷酸酶的较小.根际土的3种磷酸酶的含量极显著地高于非根际土的.根际活化磷的能力与土壤中的总磷含量、有机磷含量以及pH值和碱性磷酸酶的数量成显著正相关关系,这表明磷的活化是多因素共同作用的结果.不同林龄的云南松根际对磷的活化有一定差异,年龄小的云南松根际土与非根际土之间的有效磷差异较大.

<Abstrcat>P is one of the major nutrients for plants. A study of total-P, organic P , available-P, pH, and acid, medium, alkaline phosphatase in rhizosphere and non-rhizosphere soil of Pinus yunnanensis forest in central Yunnan province was conducted. The results showed that the difference of total-p between rhizosphere and non-rhizosphere of Pinus yunnanensis forest. was not significant, but that of available-P was significant. The pH value of rhizosphere was significantly lower than that of non-rhizosphere. Acid and medium phosphatase was the dominant phosphatase at both rhizosphere and non-rhizosphere soil and they accounted for a big portion of the total phosphatase, alkaline phosphatase accounted for a small portion. The activities of either acid, medium or alkaline phosphatase was higher at rhizosphere than those in non-rhizosphere. A positive correlation was found between available P and total-P, organic P, pH and alkaline phosphatase concentration. This result suggested that the Pinus yunnanensis forest has capability to activate phosphor at rhizosphere, but the capability was determined by multiple factors. This capability also varied with the age of Pinus yunnanensis.