外源Ni在干旱区绿洲土壤-小麦系统中的迁移及其生物有效性

以西北干旱区绿洲灌淤土为供试土壤,采用盆栽模拟试验和室内分析研究了Ni对小麦的生物效应及其在土壤-小麦系统中的迁移规律.结果表明:Ni在低添加质量分数下能促进小麦生长,但达到临界值240 mg·kg-1后,就会出现明显的毒害作用.随着Ni添加质量分数的增加,各器官中Ni含量也呈增长趋势.小麦根对Ni的富集能力最强,籽粒对Ni的富集能力最弱.随着Ni添加质量分数的增加,土壤中可交换态Ni和碳酸盐结合态Ni所占比例呈增加趋势.对小麦而言,可交换态Ni是生物有效态.

Translocation and bioavailability of Ni in arid oasis soil-wheat system

A pot experiment was conducted to study the translocation and bioavailability of Ni in arid oasis soil-wheat system. The results showed that: Ni could stimulate the growth of wheat when the concentration of Ni in soil was less than 240 mg·kg^-1, but Ni could suppress the growth of wheat when the concentration of Ni in soil was greater than 240 mg·kg^-1. The concentration of Ni in wheat increased as the concentration of Ni in soil increased. The enrichment ability of Ni in root was the strongest, and the enrichment ability of Ni in seed was the weakest. As the concentration of Ni in soil increased, the percentage of exchangeable form and carbonate bounded form increased. The bioavailability mainly depended on the exchangeable Ni in soil-wheat system.