不同品种水稻全生育期内土壤Cd赋存形态及ω(Cd)变化特征  

Characterization of Chemical Fraction of Cd in Soils Cultivated with Different Types of Rice dring Their Whole Growth Stage

作　　者：钟来元[1] 周鸿凯[1] 叶昌辉[1] 黄少峰[1] 

机构地区：[1]广东海洋大学农学院,广东湛江524088

出　　处：《西北农业学报》2012年第3期175-181,共7页Acta Agriculturae Boreali-occidentalis Sinica

基　　金：国家自然科学基金(40871156);广东省农业科技攻关项目(2009B020302005)

摘　　要：以优优128、粳籼89、湛优226和粤香占4个水稻品种为材料,通过盆栽试验模拟土壤Cd污染,采用BCR法区分土壤Cd赋存形态,从而比较水稻品种对土壤Cd赋存形态及质量分数变化的影响。结果表明,在没有施用外源性Cd情况下,水稻土中Cd主要以残渣态存在为主,而弱酸提取态、铁锰氧化物结合态、有机物络合物等形态的质量分数均较低,且后3种赋存形态质量分数差异不显著。随着外源性Cd施入量逐渐增加,土壤中弱酸提取态、铁锰氧化物结合态w(Cd)有所升高。水稻品种和生育期不同,土壤中各赋存形态w(Cd)也有所差异。粳籼89全生育期内土壤中弱酸提取态w(Cd)及在土壤总Cd中的比例均明显地高于其他3个品种,这表明,粳籼89根系分泌物及其影响下的土壤对Cd的络合与固定能力较低,致使外源性Cd长时间停留在生物有效性较高的弱酸提取态。此外,在水稻全生育期内,各土壤中弱酸提取态w(Cd)及其在总Cd中的比例随时间延长而有所降低。The chemical fraction Cd in artificially contaminated soils cultivated with different types of rice was studied by use of pot experiments.Four types of rice,namely,Youyou 128,Jingxian 89,Zhanyou 226 and Yuexiangzhan,were selected in this study.As the results shown,the chemical fraction of Cd in soils without exterior Cd input was dominated by residual fraction,and no difference was found among the contents of weak acid soluble,reducible and oxidizable fraction.After Cd was input to soils as the form of CdCl2,it was subsequently transformed to different chemical fraction according to certain propotion,while which varied greatly with the rice types and their growth stage.Among the soils cultivated with the four types of rice,the soil with Jingxian 89 had the highest content of weak acid soluble fraction together with its proportion in the total soil Cd.The above result indicated that the joint effects of soil and roots of Jingxian 89 would lead to the exterior input of Cd input remaining as the weak acid soluble fraction for long time.In addition,the content of weak acid soluble fraction as well as its proportion in the total soil Cd would be decreased as the growing time prolonged.

关 键 词：水稻土 镉 赋存形态 

分 类 号：S511[农业科学—作物学]