蚯蚓对污染土壤中黑麦草和印度芥菜吸收累积锌的影响  

Effects of Earthworm on Zn Concentration and Total-Zn Uptake of Ryegrass and Indian Mustard in Zn Polluted Soil

作　　者：王丹丹[1] 李辉信[1] 魏正贵[1] 胡锋[1] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095

出　　处：《土壤》2008年第1期73-77,共5页Soils

基　　金：国家自然科学基金项目(30370286)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．）处理与不加蚯蚓的对照处理，并种植黑麦草和印度芥菜，以研究蚯蚓活动对不同植物吸收、累积Zn的影响。结果表明：除低浓度Zn处理外（Zn≤100mg／kg），蚯蚓活动明显增加了污染土壤的DTPA提取态Zn含量，进而促进植物对Zn的吸收。蚯蚓活动同时提高了印度芥菜和黑麦草地上部和地下部生物量及植株体Zn浓度，促进了植物对土壤Zn的吸收。加入蚯蚓后印度芥菜和黑麦草中Zn总累积量较无蚯蚓对照分别提高了57．8％～131．6％、51．4％～150．5％。两种植物相比，印度芥菜植株Zn浓度明显高于黑麦草，但由于印度芥菜生物量低，不论是否接种蚯蚓，其Zn累积量均低于黑麦草（未加Zn处理除外）。黑麦草生长条件要求不高、可多次刈割，因而具有很大的修复中、轻度Zn污染土壤的潜力。Effects of earthworms on Zn uptake ofryegrass and Indian mustard in Zn-treated soils were studied. Zn was added in the form of ZnSO4 solution to the soil （1000 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. Each pot received 0.1738 g KH2PO4 and 0.1666 g Urea as mineral nutrients, and two days after earthworm introduced, 10 ryegrass seeds were sewn into the soil. After 30 days of growth, the plants were harvested, and the soil was collected and stored at 4℃. The beneficial effects of earthworms were particularly evident： Earthworms not only increased available nutrients in the soil, enhanced the plant growth, but also improved markedly availability of Zn by changing it into DTPA-Zn, thus making it easy for plants to accumulate more Zn in their tissues. It was also found that total Zn uptake in ryegrass and Indian mustard was increased by 57.8% - 131.6% and 51.4% - 150.5%, respectively. After introducing earthworms into soils the same in Zn concentration, Indian mustard was much higher than ryegrass in Zn concentration in shoots and roots, but was lower in total Zn uptake due to its lower biomass. In conclusion, earthworms, plants and their interactions may have a potential role in remediation of soils slightly or moderately contaminated with Zn soil.

关 键 词：ZN 蚯蚓 黑麦草 印度芥菜 DTPA-Zn 

分 类 号：S154[农业科学—土壤学]