蚯蚓对锌污染土壤养分状况及锌形态的影响  

Effects of Earthworm on Soil Nutrients and Zn Chemical Forms in Zn Contaminated Soil

作　　者：王丹丹[1] 巫丽俊[1] 戴莹[1] 钟树明[1] 孙华[1] 张维清[1] 李洁[1] 李辉信[2] 胡锋[2] 

机构地区：[1]环境保护部南京环境科学研究所,南京210042 [2]南京农业大学资源与环境科学学院,南京210095

出　　处：《土壤》2013年第6期1048-1054,共7页Soils

基　　金：国家自然科学基金项目(30370286);中央级公益性科研院所基本科研业务专项项目资助

摘　　要：以长江冲积物形成的高沙土为供试土壤，分别加入4个浓度的Zn（100、200、300、400mg／kg）以模拟Zn污染土壤，设置了接种蚯蚓（Pheretima sp．）处理与不接种蚯蚓的对照处理，以研究蚯蚓活动对zn污染土壤的养分状况及土壤Zn形态的影响。培养试验结果表明，供试蚯蚓能存活于设定浓度的Zn污染土壤中，对Zn的富集系数为：0．21～0．29，但蚯蚓生长率随污染浓度升高而下降，表明重金属污染仍对蚯蚓生长有一定的抑制作用。蚯蚓活动降低了土壤pH，而显著提高了土壤DTPA—Zn含量，使土壤Zn形态从残渣态、有机态向铁锰氧化态和交换态转变，提高了重金属植物有效性。另外，蚯蚓活动增加了各处理土壤的速效氮、磷以及NO3^- -N含量，而对土壤速效钾和NH4^＋-N含量无显著影响。Pot experiment was carried out to study the roles of earthworms in Zn contaminated soil, Zn was added in the form of ZnSO4 solution to the soil （1 000 g per pot） at rates ranging from 0 to 400 mg/kg and the soil was incubated for 60 days at 20℃ for fractionation and stabilization. Zn-tolerant earthworms （Pheretima sp.） were introduced into half of the pots, with the other half as control. The results showed that the employed earthworms could tolerate heavy metals and survive in Zn polluted soil tested, and their Zn enrichment coefficients were about 0.21-0.29, but the growth of earthworm was negatively affected by Zn pollution, the growth rate declined with soil polluted degree increased. Earthworm activities decreased soil pH and significantly increased concentration of DTPA-Zn of soil. In additional, earthworms made Zn fractions change from residual forms and organic forms to Fe-Mn oxides-bound and extractable forms, which contributed to increase soil plant-available heavy metals amounts. And earthworm could significantly increase available N, P and NO3^- -N contents in contaminated soil, but had no effect on soil available K and NH4^＋-N contents.

关 键 词：蚯蚓 污染土壤 Zn形态 DTPA—Zn 土壤养分 

分 类 号：S154.2[农业科学—土壤学]