水稻重金属镉含量与土壤质量关系的研究

Study on the Relationship between the Cd Content in Oryza Sativa and the Quality of Soil

采用盆栽试验的方法,考察了土壤中不同浓度的镉对水稻生长、结实及重金属镉富集的影响以及镉在水稻植株的分布情况,并进一步研究了糙米(可食部位)对镉的富集量与土壤中镉总量和有效态镉含量的关系。研究表明:低浓度的镉对水稻生长稍有促进作用,高浓度的镉对其生长并没有明显的抑制作用;镉在水稻植株中总的分布趋势为根>茎>稻壳>糙米;用4种有效态提取剂(0.1 mol/L CaCl2、DTPA、0.05 mol/L EDTA和1 mol/L NH4OAc)浸提出的有效态镉的含量和土壤中镉总量与水稻糙米中镉含量均达到显著相关水平,并确定了它们的临界值分别为CaCl2-Cd=0.71 mg/kg,DTPA-Cd=1.34 mg/kg,EDTA-Cd=0.76 mg/kg,NH4OAc-Cd=0.77 mg/kg。

Influence of different contents of Cd in soil on the growth and yield of Oryza Sativa as well as the accumulation of Cd and the total trend of distribution of Cd in Oryza Sativa under a potted experiment has been studied. Results showed that low contents of Cd has promotion effect on Oryza Sativa, but high contents of Cd has not obvious restrain on it. The total trend of distribution of Cd in Oryza Sativa is root〉stem〉shell〉rice. The relation between Cd contents in rice and total Cd in soil as well as availability Cd in soil has been investigated. The result showed that both the total Cd and the availability Cd had notably correlation with content of Cd to rice, and the critical point were CaCl2-Cd=0.71mg/kg, DTPA-Cd=1.34 mg/kg, EDTA-Cd=0.76 mg/kg, NH4OAc-Cd= 0.77 mg/kg.