生物炭对不同镉污染土壤钝化效果和小白菜镉吸收的影响

Effects of Biochar on Passivation and Uptake of Cadmium by Brassica chinensis in Cadmium-Polluted Soils

目前生物炭用量对不同镉污染水平土壤的钝化效果缺乏进一步认识,利用外源添加试验研究了不同土壤镉污染水平、不同生物炭添加量对小白菜镉吸收和土壤镉有效性的影响。结果表明,添加生物炭能降低土壤有效态镉含量和小白菜地上部镉吸收量,且随着生物炭量的增加钝化效果更明显,其中以4%的生物炭添加量的效果最佳,小白菜地上部镉含量降低了55.9%~76.0%。生物炭添加提高土壤pH值,降低了土壤有效态镉含量2.4%~62.3%,其中较低镉水平土壤有效态镉含量降幅高于较高镉水平的土壤。

In order to further understand the passivation effect of biochar dosage on different cadmium(Cd) pollution soils, exogenous Cd addition experiment was conducted to study the effects of different soil Cd levels and biochar additions on Cd uptake of Brassica chinensis and soil Cd availability. The results showed that biochar application reduced soil Cd availability and Cd absorption of Brassica chinensis. The effect of Cd passivation became more obvious with the increasing levels of biochar amendment. The effect of 4% biochar addition was the best, and the Cd content in the aboveground Brassica chinensis was decreased by 55.9%~76.0%. Different biochar additions increased soil pH value and decreased the content of soil active Cd by 2.4%~ 62.3%. The decline rate of active Cd content in soils with the lower Cd level was higher than that with the higher Cd level.