溶解性有机质对紫色土中锌形态分布的影响

The Effects of Dissolved Organic Matter on Fraction Distribution of Zinc in Purple Soil

溶解性有机质(Dissolved Organic Matter)作为有机质中生物活性和物理化学反应活性较为活跃的重要组成部分,对土壤中锌的形态分布有着重要影响,本文采用室内培养的方法,在相同的温度和湿度条件下,分析了两种不同来源的DOM在不同浓度梯度下对紫色土外源锌形态分布的影响,得出以下结论:(1)紫色土在添加DOM后,显著地促进了外源锌各形态之间的相互转化分布,酸性紫色土中DOM促进了外源锌由EX-Zn向其它形态转化,这对于减少土壤锌污染的植物毒性有一定的作用。石灰性紫色土中主要促进RES-Zn向其它形态转化,提高了锌对植物的有效性;(2)两种DOM对酸性紫色土的影响优于石灰性紫色土,影响效果DOM2>DOM1;(3)酸性紫色土形态间的相关关系程度显著,石灰性紫色土形态间的相关关系程度不显著。

Dissolved organic matter as organic matter biological activity and physical chemistry responses activeness more active important constituent. The important influence to the fraction distribution of the Zinc in the soil was discussed in this article. The incubation experiment in laboratory was used for studying the effect of two DOM with different concentration complexes with purple soil or zinc on the zinc fraction distribution. The main results were showed as following： （1） The DOM could evidently promote the fractions of exogenous zinc mutual conversion and distribution when it added in purple soil. DOM in acid purple soil promote exogenous zinc converted the EX-Zn to other fractions, this has certain function to reduce the plant toxicity of the soil zinc pollution. DOM in the calcareous purple soil mainly promoted RES--Zn converts toward other fractions, raising zinc＇s effectiveness to plant; （2）The effect of two DOM to acidic purple soil than calcareous purple soil, and the effect was DOM2 stronger than DOM1; （3）The zinc fractions in acid purple soil had a good correlation, but fractions correlation was not significantly in calcareous purple soil.