不同土壤改良剂及其组合对降低大白菜镉和铅含量的作用

为寻求有效抑制污染土壤上大白菜对重金属镉(Cd)和铅(Pb)的吸收、保持大白菜卫生品质的技术方法,利用土壤盆栽试验,对施用不同土壤改良剂及其组合降低大白菜地上部Cd和Pb含量的效应进行了比较研究.结果表明,施用改良剂对大白菜的生长具有促进作用,施用改良剂可升高土壤的pH值和降低土壤中的有效态Cd含量,施用改良剂可显著降低大白菜中Cd和Pb的含量.加入5.0 mg.kg-1 Cd,2种大白菜地上部的Cd含量在所有的改良剂处理下均超过了0.5 mg.kg-1.在投加Pb 1500 mg.kg-1后,2种大白菜在加入石灰+鸡粪+过磷酸钙后,其地上部Pb含量均小于2.0 mg.kg-1,可以满足大白菜在Pb(1500 mg.kg-1)污染土壤上的安全生产.

Effectiveness of different soil ameliorants in reducing concentrations of Cd and Pb in Chinese cabbage

For exploration of the measures and techniques in inhibiting the uptake of cadmium and lead by Chinese cabbage (Brassica pekinensis L.) and protecting the hygienic quality of the vegetable, a pot-culture experiment was carried out to compare the effects of different types of ameliorations and their combinations on reducing the concentrations of Cd and Pb in the shoot of Chinese cabbage. The results showed that the application of soil ameliorations could promote growth of Chinese cabbage, increase values of soil pH and reduce the concentration of available Cd in soils, and significantly reduce the concentration of Cd and Pb in Chinese cabbage. When soil was spiked with 5.0 mg•kg-1 Cd, the concentrations of Cd in the shoots of 2 Chinese cabbage cultivars were all higher than 0.5 mg•kg-1. After 1500 mg•kg-1 Pb was spiked in the soil, the concentrations of Pb in 2 Chinese cabbage cultivars were all lower than 2.0 mg•kg-1 under the treatment of lime + chicken manure + calcium superphosphate, which indicated that the combination of soil amelioration could meet the requirement of safety production of Chinese cabbage in Pb polluted soils (< 1500 mg•kg-1).