张士灌区土壤中镉形态的探讨

本文研究了张士灌区土壤中镉的形态。交换态占78％,可给态占18％,不溶态和碱溶态只占3—4％。在田间酸性土壤中,Cl~-是无机配位体的主要成分。镉主要与Cl~-络合而形成CdCl]~-和CdCl_2。土壤中加入石灰和钙、镁、磷肥、HCO_3~-增多,镉与之生成Cd(HCO_3)_2沉淀。在长期淹水状况下,S~-增多,镉与S~-产生CdS沉淀,难以被水稻吸收。

STUDY ON CADMIUM FORMS IN SOILS IN ZHANG-SHI IRRIGATION AREA

The forms of Cd in soils of Zhang-Shi Irrigation Area were reported in this paper. 78%of Cd existed in the soils is in exchangable form, 18%is in available form and only 3-4%is in insoluble form and in alkali-soluble form.In acid soils Cr is the major constituent of inorganic ligands which is incorporated with Cd to formCCdCl]-and CdCl2.In the case of adding limes and Ca-Mg-P fertilizers, the concentration of HCO3-in soils was increased and Cd(HCO3)2was formed and precipitated. In another case when the soil...