稻作对酸性硫酸盐土酸分布及迁移的影响  

Influence of rice cultivation on the distribution and movement of acids in profiles of the acid sulfate soil

作　　者：黄巧义[1] 杨少海[1] 唐拴虎[1] 黄旭[1] 李苹[1] 付弘婷[1] 易琼[1] 张发宝[1] 

机构地区：[1]广东省农业科学院农业资源与环境研究所农业部南方植物营养与肥料重点实验室广东省养分资源循环利用与耕地保育重点实验室,广州510640

出　　处：《植物营养与肥料学报》2016年第2期353-361,共9页Journal of Plant Nutrition and Fertilizers

基　　金：公益性行业(农业)科技专项(201003016);广东省科技计划项目(2012A020100004)资助

摘　　要：【目的】酸性硫酸盐土(ASS)酸含量极高,Fe、Al、Mn、As等有毒金属移动性强。许多开发利用方式不仅影响其成土母质黄铁矿的氧化程度并可能带来生态风险,稻作利用被认为是生态风险较低的方式。本研究开展水田和荒地两种利用条件下ASS中酸含量调查研究,探讨稻作利用方式对ASS酸含量的影响。【方法】于2013年8月,在广东省台山市发育于珠江三角洲滨海ASS的水稻田和严重酸化的长期撂荒地采集土壤样品,从土表向下0—300cm范围内采用宽45 mm的土钻每20 cm采集1个样品,每个剖面共采集15个样品。比较两种利用方式下ASS各土层土壤p H值、水溶性酸、交换性酸、吸持性酸含量,探讨稻作利用方式对ASS酸分布及运移的影响。【结果】珠江三角洲平原ASS的酸含量极高,在0—80 cm深度范围内,总存在酸含量随着土层深度加深而提高,土层深度每下降20 cm,总存在酸含量就平均提高61.62%;80 cm以下土层总存在酸含量随着土层深度下降逐渐降低,其中80—180 cm深度范围内的降幅较大,土层深度每下降20 cm,总存在酸含量就平均降低61.62%;当土层深度下降至220 cm时,p H值上升到6.0,酸含量非常低。稻作利用方式显著影响ASS的酸含量及其在土壤剖面的迁移情况。与荒地比较,稻田0—80 cm土层的总存在酸含量显著降低,其中水溶性酸、交换性酸和吸持性酸含量平均降幅分别为77.01%、36.75%、27.74%,水溶性酸和交换性酸的差异达到显著水平,吸持性酸仅在0—20 cm和60—80 cm土层的差异达到显著水平;100—120 cm深度范围内稻田的总存在酸含量显著高于荒地,其中水溶性酸、交换性酸和吸持性酸含量的增幅分别为128.19%、54.87%、154.96%,120—240 cm土层中,稻田的交换性酸和吸持性酸含量稍高于荒地,但差异不显著;240—300 cm土层中,稻田的酸含量与荒地基本相同。总体上,稻作方式改变了ASS中酸在土壤剖面�【Objectives】Acid sulphate soil（ ASS） has high acid content and high mobility of Fe,Al,Mn,and other potentially toxic elements. Cultivation models significantly affect the oxidation of the main parent material ofASS（ pyrite） and bring ecological risks. Rice cultivation has been considered as a model with low ecological risk.Therefore,this study on the acid content of ASS was conducted in paddy fields and abandoned land respectively,in order to examine the effects that rice cultivation has on the acid content of ASS and to confirm this conclusion.【Methods】Acid sulfate soil samples were collected from paddy fields and fallow land in the coastal area of Pearl River Delta in Taishan City,Guangdong Province in August,2013. The soil samples were collected at 20 cm intervals in soil profiles of 300 cm in depth at five locations. The p H value,soluble acidity,exchangeable acidity,retainable acidity and soluble sulphate were determined. 【Results 】 The acid content varied according to soil depth. The total acidity from 0 to 80 cm deep increased by 62% every 20 cm deeper. From 80 to 220 cm deep,the total acidity decreased by 62% every 20 cm in depth from 80 to 180 cm. The acidity in soil profiles between 220 and 300 cm remained stable and very low with a p H value of approximately 6. 0. Rice cultivation influenced the distribution and movement of acid in ASS profiles significantly. Compared to abandoned land,the total amount of acidity present in soil from 0 to 80 cm in depth in paddy fields decreased significantly,while soluble acidity,exchangeable acidity and retainable acidity decreased by 77%,37% and 28% respectively,and the difference in soluble acidity and exchangeable acidity was at a significant level whereas retainable acidity decreased significantly only in soil layers from 0-20 cm and 60-80 cm in the paddy fields. However,the total amount of acidity existing in soil from 100 to 120 cm in depth in paddy fields was significantly higher than in the abandoned land,while soluble acidity,exchangeable

关 键 词：酸性硫酸盐土 稻作 酸 迁移 

分 类 号：S153[农业科学—土壤学]