Progress in Fertilization on Behavior of Heavy Metals in Contaminated Soils

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.