NH_4/NO_3配比对土壤镉和锌形态及其生物有效性的影响  

Effect of the Ratio of NH_4^+/NO_3^-on the Form and Bioavailability of Cd and Zn in Soil

作　　者：吴花[1] 李伏生[1] 莫江华[1] 

机构地区：[1]广西大学农学院,广西南宁530005

出　　处：《农业环境科学学报》2007年第5期1865-1869,共5页Journal of Agro-Environment Science

基　　金：国家自然科学重点基金(50339030;50528909)

摘　　要：采用盆栽试验研究不同铵态氮和硝态氮(NH4/NO3)配比(%/%)对土壤中镉和锌形态及其生物有效性的影响。结果表明,随着施入NO-3-N的比例提高,土壤pH值增加,土壤中水溶交换态镉和锌含量以及苋菜(Amaranthanus tricolour)吸收镉和锌的能力显著降低。这表明土壤施入不同配比NH4/NO3后,通过改变土壤pH而影响土壤镉和锌形态,从而影响镉和锌的生物有效性,因此农业生产中可通过选择合适的氮源来减少蔬菜对镉的吸收,以保障农产品安全。Application of different rabos of ammonium and nitrate （NH4^＋/NO3^-） （%/%） can alter soil pH, which will directly change the forms of Cd and Zn in soil. A pot experiment was carried out to study the effect of different ratios of NH4^＋/NO3^- on the form and bioavailability of Cd and Zn in soil. Two experimental factors were included, five different ratios of NH4^＋/NO3^-, i.e. 100/0, 75/25, 50/50, 25/75, 0/100, three different cadmium levels, i.e. 0, 3, 5 mg·kg^-1, giving a total of 15 treatments. The maximum fresh weight per amaranth plant （Amaranthanus tricolour） was observed when the ratio of NH4^＋/NO3^- was 25/75, but the fresh weight per plant reduced with the increased Cd level to some extent. With the increasing of NO3^--N proportion, soil pH increased, but the contents of water-soluble and exchangeable Cd and Zn in soil and the absorption of Cd and Zn by amaranth plant reduced significantly, indicating that the change of soil pH after applied into different ratios of NH4^＋/NO3^- influenced the form and bioavailability of soil Cd and Zn. Thus in the agricultural production, selecting appropriate N source as fertilizer can reduce the uptake of Cd by vegetables so as to safeguard the security of agricultural product.

关 键 词：镉 锌 形态 生物有效性 

分 类 号：X53[环境科学与工程—环境工程]