采用重金属污染水稻土开展盆栽试验,研究施用有机碳源、菜籽饼和猪粪对不同水稻(汕优63,简称“SY63”;中浙优1号,简称“ZZYl”)重金属吸收的调控效应。结果表明,在重金属污染土壤上ZZYl具有一定的耐性,相同处理时ZZYl糙米、砻糠、秸秆中重金属含量均低于SY63品种,糙米中Cd含量较SY63低57.5%~83.8%,Cu含量低37.8%~69.1%,Zn含量低0.88%~31.7%,食物链风险较SY63品种低。3种有机物料中,施用菜籽饼使两水稻品种糙米中重金属含量明显低于其他处理;与对照相比,施用菜籽饼使SY63糙米中Cd、Cu和zn含量降低73.5%、52.6%和32.1%,ZZYl糙米Cd含量降低30.5%。在供试重金属污染土壤上可选择具有一定重金属耐性的水稻品种ZZYl进行粮食生产,同时施用适量的菜籽饼以增强其抵御重金属毒害的能力,降低糙米中Cd、Cu和Zn含量及其食物链污染风险。
A pot experiment was carried out to investigate the effects of three organic amendments (organic carbon material, rapeseed cake and pig manure) on the growth and heavy metal uptake of different rice cultivars, Shanyou 63(SY63) and Zhongzheyou I(ZZY1) in a heavy metal mixed contaminated paddy soil. The results showed that ZZY1 was a metal tolerant cultivar, the heavy metal concentration in brown rice, husk and straw were lower than that of in SY63 cultivar. Compared with SY63, the concentrations of Cd, Cu and Zn in ZZY1 brown rice decreased by 57.5% - 83.8%, 37.8% - 69.1% and 0.88% - 31.7%, respectively, and resulted in lower food-chain heavy metal risk. Application of rapeseed cake significantly decreased heavy metal concentration in brown rice of both cultivars. Compared with the control, application of rapeseed cake decreased concentrations of Cd, Cu and Zn in brown rice of SY63 by 73.5%, 52.6%, 32.1%, and Cd in ZZY1 by 30.5% respectively. This indicated that growing ZZY1 and applying proper amount of rapeseed cake to heavy metal contaminated paddy soil could decrease heavy metal concentrations in rice plant and achieve high yield with low food-chain heavy metal risk.