施磷肥对蓖麻吸收土壤中铜的影响

Effect of Phosphate Fertilizer on Uptake of Copper in Soil by Castor

为提高蓖麻对铜的富集能力,在湖北省黄石市铜矿区农用地开展田间实验,通过施用不同水平的过磷酸钙,探究磷对蓖麻生长和吸收铜以及土壤铜形态的影响。结果表明,施磷增加了蓖麻的干物质量,当施磷量(以P_(2)O_(5)计算,下同)为144 kg·hm^(-2)(HP)时单株根、茎和叶干质量均达最大值,分别是只施氮钾肥(NK)处理的2.3,1.9和1.6倍(P<0.05)。蓖麻对土壤铜的总吸收量随着施磷量的增加而显著增加,施磷促进铜从根向茎的转移,其转运系数增加了21.7%~26.1%。而且,当施磷量为36 kg·hm^(-2)(LP)和72 kg·hm^(-2)(MP)时降低了土壤酸溶态铜含量,增加了残渣态铜含量,而HP处理增加了土壤CEC和DOC含量。总之,当施磷量为72和144 kg·hm^(-2)时,蓖麻对铜的提取均有较好的效果。

To improve the accumulation ability of castor to copper,a field experiment in the copper mine area in Huangshi city of Hubei province was conducted.The effects of phosphorus on the growth,copper uptake by castor,and change of copper forms in soil were studied by applying different levels of calcium superphosphate(Ca(H_(2)PO_(4))_(2)).Results show that the phosphorus application increases the dry weights of castor.When the fertilization rate of phosphorus(P_(2)O_(5))is 144 kg·hm^(-2)(HP),the dry weights of roots,stems and leaves of castor are 2.3,1.9 and 1.6 times higher than that with treatment by only nitrogen and potassium(NK).The total copper uptake by castor significantly increases upon increasing the phosphate fertilizer.After applying phosphorus fertilizer,the translocation factor of copper from the root to the stem in castor increases by 21.7%—26.1%.Moreover,when the fertilization rates of phosphorus(P_(2)O_(5))application rate are 36 kg·hm^(-2)(LP)and 72 kg·hm^(-2)(MP),the content of acid extractable copper decreases and that of residual copper increases.The HP treatment increases the CEC and content of DOC in soil.In a word,when the phosphorus application rates are 72 and 144 kg·hm^(-2),castor holds a better remediation efficiency for the Cu contaminated soil.