磷胁迫条件下油菜、肥田萝卜对难溶性磷的活化与利用

MOBILIZATION AND UTILIZATION OF SPARINGLY SOLUBLE P BY RAPE AND RADISH UNDER P-DEFICIENCY

通过砂培试验研究了北方食用油菜和南方绿肥作物肥田萝卜两种植物在缺磷胁迫条件下对难溶性磷酸盐Ca_3(PO_4)_2和AlPO_4的活化利用情况。试验结果表明,在仅供应一种难浴性磷酸盐时,油菜和肥田萝卜对磷酸铝和磷酸三钙都有较大程度的活化与利用。在施用AlPO_4时肥田萝卜地上部吸磷量达到供应等磷量水溶性磷酸盐时的90％;在施用Ca_2(PO_4)_2时油菜地上部吸磷量达到供应等磷量水溶性磷酸盐时的49％。植物干物重的测定结果说明,在缺磷时,难溶性的Ca_3(PO_4)_2及AlPO_4对油菜和肥田萝卜均有促进生长的作用。但是,油菜与肥田萝卜对Ca_3(PO_4)_2和AlPO_4的活化利用程度却存在着一定差异。表现为油菜对Ca_3(PO_4)_2的利用能力强,而肥田萝卜对AlPO_4的利用能力强。

The capacity of rape and radish, plants of two different ecotypes, to mobilize and utilize sparingly soluble phosphates, AlPO4 and Ca3(PO4)2 was demonstrated by quartz sand culture. The results showed that when supplied with only one insolule phosphate, both rape and radish could mobilize AlPO4 and Ca3(PO4)2 by a large degree. When fertilized with AlPO4,the shoot P amount of radish reached 90 percent of the one supplied with the same amount of soluble phosphates, for rape supplied with Ca3(PO4)2. the percentage was 49%. The analysis of plants dry weight indicated that soil sparingly soluble phosphates, Ca3(PO4)2 and A1PO4 were able to improve the growth of rape and radish. Howerer, there was divergence in the degree by which rape and radish utlized the two insoluble phosphates. Comparatively, radish grown in acid soils had much higher ability to absorb P from A1PO4 than from Ca3(PO4)2, whereas rape native to calcareous soils utilized Ca3 (PO4)2 more efficiently than A1PO4.