杉木檫树根际土壤磷素研究*

檫树根际土攘的全磷、有机磷和有效磷含量明显高于杉木根际土。两种林木根际土的无机磷总量无显著差异，但无机磷的组成有很大不同，表现在杉木根际土闭蓄态磷比例很高（占无机磷的61.48%），而檫树根际土明显低（仅占39.69%）。檫树根际土Fe-P，Ca-P的含量显著高于杉木根际土。杉木、檫树根际土中的有效磷都和AI-P，Ca-P显著相关，AI-P的含量都偏低，特别是杉木根际土。

Studies on Soil Phosphorus of Rhizosphere under Chinese Fir and Chinese Sassafras

There is higher content of total-P, organic-P and availabe-P in the rhizosphere soil of Chinese sassafras than that of Chinese fir. Between the rhizosphere soils of the two kinds trees, there is no significant difference in mount of mineral phosphorus but is significant difference in its constituent, which can be explained by much more content of occluded-P (acounted to 61.48% of mineral phosphorus) in Chinese fir rhizosphere soil than that (acounted to 39.69%) in Chinese sassafras, and by much more content of Fe-P and Ca -P in Chinese sassafas rhizosphere soil than that in Chinese fir. In two rhizosphere soils, the qauntity of available-P is largely correlated with contents of AI-P and Ca-P, while there is lower content of AI-P.