【摘要】 采用网膜分隔三室栽培系统研究了供磷水平不同的石灰性土壤中,油菜根际磷的各种化学组分的动态分布特征。发现在正常供磷水平下油菜根际范围内Olsen-P,Ca₂-P均处于亏缺状态,表明这两种形态的磷是油菜吸磷的主要给源。而在土壤磷极度缺乏条件下,根际Ca₈-P和Al-P呈现亏缺状态,该二种磷成为油菜吸磷的给源,这时Olsen-P和Ca₂-P反而呈现均匀分布。这一结果表明,在严重缺磷胁迫条件下,油菜根际的难溶性磷（Ca₈-P和Al-P）可以被活化而为植物利用,成为生物有效磷。这是油菜抗低磷胁迫根系适应反应的间接证明。更多还原

【Abstract】 Phosphorous dynamic and distribution in rhizosphere of rape seedlings was studied in a three-compartment-pot separeted by net on the calcurous soil with three P levels. Olsen-P and Ca (Ⅱ) -P depleted occurred in the rhizosphere at normal phosphorous level. Indicating that those two forms of phosphorous were the main P source for rape. However, where soil at very low P level, Ca (Ⅷ) -P and A1-P depleted in rhizosphera and became main P source to rape, and Olsen-P and Ca (Ⅱ) -P were uniform distributed in rhzosphere of rape. The results above indicated that sparingly-soluble phosphorous had been mobilized and became bioavailable in rhizosphere of rape seedlings.更多还原