摘要
积累在砂质土壤中的铜、锌和磷主要以可提取态形式存在,具较高的活性。pH对这些土壤中Cu、Zn和P的溶解度有很大的影响,这3种元素对酸化溶解的敏感性为P>Zn>Cu。不同淋洗剂对砂质土壤中Cu、Zn和P的淋出量有较大的差异,淋出量排序为EDTA>稀酸>>稀盐和去离子水,并与土壤中Cu、Zn和P的存在形态有关。在当前利用方式并保持较高土壤pH的条件下,Cu和Zn相对较为稳定,但P却较易溶解而流失;当这些土壤被废弃而酸化或转为林地后,有机质积累和可溶性有机物质增加将促进Cu、Zn和P的淋溶流失。
Water quality impacted by heavy metals and nutrients accumulated in soils is a major environmental concern.Understanding the stability of the heavy metals and nutrients in the soils under different conditions is necessary to predict their potential impacts on water quality.In this study,the stability of Cu,Zn and P accumulated in sandy soils was examined by simulative leaching with deionized water,0.01 mol·L^(-1) CaCl_2,0.01 mol·L^(-1) HNO_3,and 0.01 mol·L^(-1) Na-EDTA.The chemical forms of Cu,Zn and P in the soils were also examined using a sequential fractionation method.The results indicated that most of Cu,Zn and P accumulated in the sandy soils were extractable fractions with high activity.pH had a great influence on solubility of Cu,Zn and P in the soils.Sensitivity to acidification of the solubility of the three elements decreased in the order of P>Zn>Cu.The concentrations of Cu,Zn and P in leachates varied greatly with leaching agents.The amounts of Cu,Zn,and P leached from the soils were Na-EDTA > 0.01 mol·L^(-1) HNO_3 >> 0.01 mol·L^(-1) CaCl_2 and deionized water,and related with chemical forms of Cu,Zn and P in the soils.The results suggested that Cu and Zn in the soils were more stable as compared with P under the current land use with high soil pH.However,soil acidification or/and increased soil soluble organic matter induced by afforestation may increase the release of Cu,Zn and P from the soils.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2005年第z1期56-61,共6页
Journal of Agro-Environment Science
关键词
砂土
CU
ZN
P
稳定性
sandy soils
copper
zinc
phosphorus
stability
