摘要
施肥作为农业生产中最普遍的增产措施,也具有促进重金属形态转化从而达到修复污染土壤的作用,从其影响重金属有效性的机理及植物效应两方面阐述了国内外的研究进展。研究表明氮肥主要通过硝态、铵态氮的根际碱化和酸化效应来影响重金属的活性;磷肥不仅通过三种酸根(H2PO-4,HPO24-,PO34-)形式来影响土壤表面电荷,进而影响土壤对重金属的吸附,而且其陪伴阳离子(Ca2+、Mg2+)也有一定贡献;钾肥的效果主要表现为伴随阴离子的作用,氯离子可降低土壤对金属阳离子的吸附,硫酸根、磷酸根作为专性吸附离子对其作用相反,硝酸根的影响较小。肥料对重金属的作用实质上是在不同条件下离子间的相互作用,最终影响了重金属的植物有效性。文章在归纳分析的基础上,对今后该方面的研究进行了展望。
As an important way for increasing yield in agricultural production,fertilization also can accelerate remediation of contaminated soil by heavy metal.The mechanism of bioavailability and plant response of heavy metals and some development of the research were introduced in this paper.It has been showed that nitrogen fertilizers affect bioavailability of heavy metals through basification of nitrate and acidification of ammonia in rhizosphere and accompanying anions;Phosphorous fertilizers can alter soil surface charge by three types of acid radical,such as H2PO-4HPO2-4and PO3-4,which influence metal ions sorption by soil.Moreover,its accompanying cations also contribute to this process.However,the effects of potassium fertilizers mainly lie in accompanying anions,as Cl-can decrease cation sorption by soil,SO2-4 and H2PO-4 which are specific sorption ions with an adverse function,and little effect is found from NO-3.Actually,the effect of fertilizer on heavy metals is an interaction between anion and cation under different conditions,which results in various bioavailability of heavy metals.Some further study of this subject is stressed.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2006年第S1期328-333,共6页
Journal of Agro-Environment Science
基金
国家重点基础研究发展规划(973)项目(2002CB410809)
农业部农业环境与农产品安全重点开放实验室开放基金
关键词
氮
磷
钾
重金属
形态
植物效应
nitrogen
phosphorus
potassium
heavy metals
speciation
bioavailability
