汞镉铅复合污染菜地施用石灰对菜心及土壤的影响

Effects of Limestone on Brassica chinensis L. and Soil in Vegetable Field Compound Contaminated by Hydrargyrum, Cadmium, Plumbum

采用盆栽实验研究了在汞镉铅三级水平复合污染的菜地上施用不同量Ca(OH)2(石灰)对菜心生长、生理及品质的影响,同时探讨了汞镉铅在菜心中的富集量及土壤中有效态汞镉铅含量。结果表明,适量施用Ca(OH)2(使得土壤pH约为6.45左右)能明显降低重金属对菜心的毒害,促进菜心较好的生长,生物量较对照明显提高,品质也明显优于对照;但当Ca(OH)2施用过量致使土壤呈现强碱性时这种效果并不明显甚至有不及对照的趋势;而汞镉铅在菜心中的富集量以及土壤中有效态汞镉铅含量则随Ca(OH)2施用量的增加而降低。

Series of pot experiments were performed to determine the effects of Ca（OH）2 （limestone） on the growth, the physiology and the quality ofBrassica chinensis L. in the vegetable field compound contaminated by Hg, Cd, Pb. The accumulation of hydrargyrum（Hg）, cadmium （Cd）, plumbum （Pb） in Brassica chinensis L. and the bio-available content of Hg, Cd, Pb in soil were also analyzed. The results showed that the application of Ca（OH）2（made the pH about 6.45） significantly increased soil pH value, reduced the toxicity of the heavy metals and promoted the yield and quality of Brassica chinensis L.. But over use of Ca（OH）2 （made the soil pH〉7）did not reach this effect, even worse than CK. As more Ca（OH）2 used, the soil pH increased, the contents of Hg, Cd, Pb in Brassica chinensis L. and the contents of available Hg, Cd, Pb in soil reduced. Considering the growth, physiology, yield and quality of Brassica chinensis L., the accumulation of Hg, Cd, Pb in Brassica chinensis L. and the contents of available Hg, Cd, Pb in soil, the best amending effect of Ca（OH）2 was to make the pH about 6.45 in the acidity land compound contaminated by Hg, Cd, Pb.