磷影响下砷的根际效应及其对水稻生长的影响

Effects of Arsenic under Effects of Phosphorus in Rhizosphere and on Growth of Rice

通过水稻的生物量及含砷量、根际 p H值、根际有效砷的变化来研究磷影响下砷的根际效应及其对水稻生长的影响。结果表明 ,酸性紫色土中 ,无论单加砷还是磷、砷共存的处理 ,基本上 ,根际砷均高于非根际 ,砷在根际呈富集状态 ;但与单加砷相比 ,磷、砷共存的处理 ,根际 p H值下降 ,有效砷减少 ,水稻吸收砷量减少 ,生物量增加 ,水稻受砷毒害减轻 ,特别 P/As≥ 4时 ,磷减轻砷毒害的程度大于 P/As≤ 2时。因此 ,施加磷可减轻砷污染酸性紫色土上水稻砷毒害。选择最佳 P/As可使磷最大限度地减轻作物受砷的毒害。

This paper studied effects of arsenic in rhizosphere and arsenic effected by phosphorus through the growth of rice,the pH value of rhizosphere soil,the effective arsenic and phosphorus.The results showed that,in acid purple soil,the effective arsenic in rhizosphere soil of only arsenic treatment and arsenic and phosphorus co-existed was higher than that in nonrhizosphere and accumulated in rhizosphere.Compared the treatment of arsenic and phosphorus co-existed with only arsenic treatment in rhizosphere,the pH value was decreased,effective arsenic was reduced,effective phosphorus was increased.The arsenic content in rice was reduced,but phosphorus content was increased.The biomass of rice was increased toxicity of arsenic on rice was reduced.When P/As=4,the toxicity of arsenic on rice was lower than that of treatment when P/As=2.Therefore,phosphorus could be used to reduce the toxicity of arsenic on rice in acid purple soil polluted by arsecic.It is necessary to select the optimum P/As.