镉污染稻田专用土壤调理剂修复效果评价

摘要

A field experiment was conducted to evaluation of remediation effect of 14 soil conditioners dedicated for Cd Polluted paddy fields contrasted with conventional fertilization and liming. The results showed that soil conditioners had no significant impact on rice yield. Though the soil conditioner had a stable effect on decreasing Cd content in grains, the effect varied in reducing Cd concentration. In general, the Cd contents of early rice and late rice were reduced 22.65％ to 44.24％ and 15.20％ to 63.03％, respectively. Additionally, the stem and leaves showed the same decreasing tendency. Cluster analysis suggested that soil conditioner can be divided into three types, the first type is to increase the soil pH so as to inhibit the Cd activity and cut down the Cd translocation from soil to stem and leaves, which exhibited the most efficient to reduce Cd content in rice; the second type was common effect on reducing Cd, which was mainly rely on antagonism or co- precipitation provided by its medium or micro elements absorbed by rice so as to inhibit the translocation and redistribution from stem to rice; the last type was medium effect whose mechanism contained both the first and the second type.%采用大田试验,以常规施肥为对照,并与施用石灰进行对比,对14个镉(Cd)污染稻田土壤专用调理剂进行效果分析与评价.结果表明:施用土壤调理剂对水稻产量无显著影响;土壤调理剂降低稻米Cd含量的效果相对稳定,但不同土壤调理剂降低稻米Cd含量的效果存在较大差异.早、晚稻施用土壤调理剂的稻米Cd含量降幅分别为22.6％～44.2％ 和15.2％～63.0％,降低水稻茎叶Cd含量的效果与之趋势相同.聚类分析结果表明,土壤调理剂主要分为三类:第一类依靠提升土壤pH值,钝化土壤Cd活性,减少土壤Cd向水稻体内迁移转运,降低稻米Cd含量的效果较好;第二类主要利用相关元素与镉产生的拮抗作用,抑制水稻茎秆中Cd向稻米的迁移和再分配,但降Cd效果一般;第三类为中等稻米降Cd效果的产品类型,其作用机制可能是前两类的效果兼而有之,但稻米降Cd效果有待增强.