蚯蚓对黑麦草在土壤体系中镉迁移影响的研究

Effects of Earthworm on Cd and Its Accumulation of Ryegrass in Soil

【目的】探讨蚯蚓在高浓度镉污染土壤植物修复中的作用,以便为进一步利用蚯蚓改善植物修复技术提供理论依据。【方法】以灰漠土为供试土壤,在两种Cd浓度(200和500 mg/kg)处理下,模拟高浓度Cd污染土壤,设置了接种不同数量(10、30和50条)蚯蚓和不加蚯蚓的对照处理,并种植黑麦草以研究高浓度Cd污染土壤中不同数量蚯蚓活动对黑麦草富集Cd的影响。【结果】加入蚯蚓提高了黑麦草的生物量,在2个浓度的处理中加入10条蚯蚓黑麦草生物量增长最大,分别为对照的135.8%、146.3%。在200 mg/kg Cd处理下,蚯蚓提高了黑麦草地上部和地下部Cd浓度,30条蚯蚓对黑麦草地上部Cd的富集影响最大。在500 mg/kg Cd处理下,蚯蚓提高了黑麦草地上部Cd浓度,但对地下部Cd浓度影响不显著。【结论】蚯蚓活动不仅能促进黑麦草生物量的增长,而且能促进黑麦草对Cd的吸收。

【Objective】Effects of earthworms on Cd accumulation of ryegrass in Cd treated soils were studied.【Method】The experiment consisted of two levels of Cd addition（200,500 mg/kg）and four earthworm treatments（0,10,30,50）.Each treatment had three replicates.500 seeds of ryegrass（Lolium multiflorum）were sowed in each pot（1.5 kg soil）and harvested after 40 days.【Result】The result indicated that the biomass of ryegrass reached the highest when 10 earthworms were added.Total Cd uptake in ryegrass shoot and root were increased by earthworm activity in Cd 200 mg/kg soil.Total Cd uptake of ryegrass shoots was the highest in the concentration with 30 earthworms.Total uptake of Cd by the ryegrass shoot was enhanced by earthworm activity in Cd 500 mg/kg soil,while no significant difference was observed in concentration of Cd in plant root.【Conclusion】Earthworm activity significantly enhanced ryegrass growth.It was also found that Cd uptake in ryegrass was increased.