中文摘要：

农田镉（Cd）污染一直是人们关注的热点,通过室内盆栽实验和野外田间实验相结合,研究了不同钝化剂对小麦根部与籽粒中Cd富集量的影响,同时采用野外实验考察了2013年至2016年四年收获期内钝化剂的持久性.结果表明：盆栽实验中,施加固定剂后对土壤中Cd均有不同程度的钝化作用.田间实验中,刚施加固定剂后的第一季小麦中,各组固定剂均使小麦根和仔粒中Cd浓度有较为显著的降低,这和盆栽实验中结果基本一致.随着时间的推移,固定剂在土壤中对重金属的钝化作用逐渐降低,各处理组中钝化持久性效果最好的是钙镁磷肥及其配施石灰组和磷矿石配施石灰组,并且这三种钝化剂处理方式的有效性一直持续到2015年的第三季小麦.当时间持续到2016年第四季小麦时,各钝化剂处理组相对于空白对照之间已经没有显著性的差异.综上,在钝化修复农田土壤Cd污染时,可以优先选择钙镁磷肥配施石灰的钝化剂,同时需要跟踪监测钝化效果,必要情况下需要复施以确保固定剂的效果稳定.

英文摘要：

Soil Cd contamination is of great concern and often remediated by addition of amendments to reduce its mobilization.In this study,we compared a couple of commonly used soil amendments,such as calcium montmorillonite（MT）,fused calcium-magnesium phosphate（CMP）,phosphorus rock（PR）.Triple superphosphate（TSP）and lime（L）using in-door pot experiments and testified the results with field experiments lasting 4years from 2013-2016.Pot experiments using wheat showed that CMP＋L had the best immobilization effect for Cd.The results of field experiments generally agreed with pot experiments.The first season showed the best immobilization effect for Cd,but the immobilization effect weakened with time.At the third crop season,the treatment of CMP＋L and PR＋L still significantly decreased Cd concentration in wheat.But all the amendments showed almost no effect on the fourth season.We also observed that the production of wheat increased in the first season with phosphorus materials,but this positive effect disappeared in the second season of wheat.In summary,the CMP＋L was found to be the best amend-ments to reduce Cd risk to wheat.But the remediation effect needs to be monitored and further addition of amendments might be required to keep the immobilization effect.