污染土壤上水稻生长及对Pb、Cd和As的吸收

通过温室盆栽试验研究了Pb、Cd和As于中国土壤环境质量标准III级水平(Pb:400 mg/kg;Cd:1.0 mg/kg:As:40 mg/kg)时对水稻在3种不同类型土壤上的生长和吸收Pb、Cd及As的影响.结果表明:在红壤上,As处理的稻谷产量显著降低,除Cd处理对稻谷产量影响不大外,其他处理也明显降低了水稻稻谷产量,且 Pb、Cd 的存在加重了As的毒性;对稻草产量只有Pb和Pb-Cd-As两个处理与对照有显著性差异.在乌栅土上,仅As和Pb-Cd-As处理与对照相比明显降低了稻谷产量,而所有复合处理均降低了稻草产量,且对稻草产量影响要大于其对稻谷产量的影响.在青紫泥上各处理影响较小.Cd-As、Pb-Cd和Pbr-Cd-As处理红壤其稻米Cd含量较Cd单独存在时分别增加了15.7%、11.5%和25.6%;红壤上Pb处理显著增加了稻米Pb的含量.但Pb-As处理降低了稻米Pb含量.稻米中重金属含量在3种不同性质土壤上的含量大小顺序为:红壤>青紫泥>乌栅土.

Growth and Uptake of Pb, Cd and As of Rice in Polluted Soils

Pot experiments were conducted to study the effects of Pb, Cd and As in single and combined forms in three different kinds of soils on the yield of and accumulation of heavy metals in rice (Oryza sativa L.). The results showed that, in the red soil, As treatment decreased rice yield significantly, except Cd treatment which showed little affect on rice yield other treatments decreased rice yields significantly, while the coexistence of Pb or Cd aggravated the toxicity of As, whereas, the combined effect of Pb-Cd-As on rice yield in other two soils was less significant than that in the red soil. But straw yields were different between the treatment Pb, Pb-Cd-As and the control (CK). In Wushan soils, only the treatment of As and Pb-Cd-As decreased rice yields compared with CK, and the combined treatments reduced straw yields. In the red soil, rice Cd concentrations of the treatments of Cd-As, Pb-Cd and Pb-Cd-As decreased by 15.7%, 11.5% and 25.6% compared with single Cd treatment, respectively. Pb treatment increased significantly rice Pb concentration in red soil, but Pb-As treatment decreased it. The concentrations of heavy metals in rice were in the following order as red soil > Qingzi soil > Wushan soil.