蚯蚓对As污染土壤酶活性及其P养分的影响

Effects of Earthworm on Enzyme Activities of Soil Polluted by Different Concentrations of Arsenic

从湖南石门县的As矿区附近采集不同程度As污染的农田土壤,分别设置添加秸秆、接种蚯蚓等处理,研究蚯蚓对As污染土壤酶活性及其P养分供给的影响。结果发现,高浓度As土壤的脱氢酶活性显著低于中、低浓度As土壤,而酸性磷酸酶活性及有效P含量则与之相反。蚯蚓+20g秸秆处理在50d时脱氢酶活性最高,而酸性磷酸酶活性则是秸秆处理在100d时最高,且接种蚯蚓和施用秸秆有利于土壤P素的释放。结果表明在施用秸秆条件下接种蚯蚓有利于改善As污染土壤的养分供给,从而改善根际营养。

A pot culture experiment was carried out to investigate the effects of earthworm （Eiseniafoetida） on the activities of dehydrogenase and phosphatase and bioavailable P in arable soil sampled near the largest Arsenic mine of Asia in Shimen County, Hunan Province. Dehydrogenase activities, phosphatase activities and bioavailable P were all impacted by inoculable earthworm, corn residues and the concentration of Arsenic in soil. Dehydrogenase activity was much lower in high As level than that in low and medium As level. However, the trend of phosphatase activities and bioavailable P, compared with dehydrogenase activities, were reversed. Dehydrogenase activities in the soil inoculated earthworm and put on rice straw was the highest when samples were collected at the 50th day, and phosphatase activities were the highest at the 100th day. Inoculating earthworm and putting on rice straw in As-polluted soil were in favor of P released from the soil. The results showed that inoculating earthworm in As-polluted soil could ameliorate nutrient supply in the rhizosphere and might be beneficial to the plant, phytoremedying As-polluted soil.