Distribution　and　Transformation　of　Native　and　Added　Ni　Fractions　in　Purple　Soils　from　Sichuan　Province

作     者：TU CONG(College of Resources and Environment,Southwest Agricultural University,Chonyqiny 630716 China) 

作者机构：College of Resources and Environment Southwest Agricultural University Chongqing 630716 China 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：1996年第6卷第2期

页      面：183-192页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 090301[农学-土壤学] 

主　　题：distribution Ni fraction purple soil tracer technique transformation 

摘      要：The distribution and transformation of added and native Ni in purple soils were investigated with both sequential extraction procedure and isotopic tracer *** distribution of added and native Ni was greatly dependent on soil *** soil PH was favorable for soluble plus exchangeable (EX) Fraction,while Fe/Mn oxides and clay for Fe/Mn oxide bound (OX) and residual (RES) fractions. The added Ni,however,has not yet reached the distribution equilibrium up to the 150th day after *** was reflected in the fact that the proportion of EX fraction from added Ni was 150%-600% as much as that of native Ni, while that of RES fraction was only about 80%.Once entering soil, the applied soluble Ni was rapidly transformed into Other fractions, but the organic complexed (OM) fraction of added Ni was relatively stable during *** carbonate bound(CAB) fraction showed a progressive increase and attained a peak value after 0-14 d of incubation and thereafter decreased gradually. The occurrence time of this peak advanced as initial soil PH increased, but the peak would disappear when initial soil pH was higher than 7.5(or containing free CaCO3). The transformation processes of the EX,OX and RES fractions could be described by Elovich and two-constant rate equstions,and the rates were positively correlated with soil pH,CEC and *** findings could explain why there are differences in ecological and environmental effects of Ni in different soils and at various intervals.