落叶松根际土壤磷的有效性研究

野外用剥落法采集落叶松(Larixgmelini)根际土与非根际土,分析P浓度的变化,结果表明,落叶松根际土与非根际土全P浓度无明显差异,但根际土有效P却明显高于非根际土.12年生时根际土有效P增加12.6%,40年生时增加23.4%,表明落叶松根际对土壤中的P具有活化作用.落叶松根际土无机P各组分与非根际土亦有差异,表现出根际土OP低于非根际土,AlP、FeP、CaP和NH4ClP则高于非根际土的趋势.落叶松根际土的pH低于非根际土,但落叶松根际并未发生明显酸化.落叶松根际有效P与pH变化相关不显著.

Soil P availability in larch rhizosphere

Soil samples were collected from the rhizosphere, non rhizosphere of larch(Larix gmelini) stand by exfoliation method,, the variation of P concentration was analyzed. The results show that there was no significant difference between total P concentrations in the rhizosphere, the non-rhizosphere soil,while the concentration of available P in rizhosphere soil was significantly higher than that in the non-rhizosphere soil.The concentrations of available P in rhizosphere 12 years old, 40 years old larch rhizosphered by 12.6%, 23.4% respectively,indicating that larch roots had the effect of mobilizing soil phosphorus.The components of inorganic P in rhizospheric soil were different from those in non-rhizospheric soil.The concentration of O-P was lower,and the concentrations of Al-P,Fe-P,Ca-P,NH₄Cl-P were higher in the rhizosphere.The pH of rhizospheric soil was lower than that of non-rhizospheric soil,but no further acidification was observed.There was no close relationship between pH variation, available P concentration in larch rhizosphere.