Effect of Organic Acids and Protons on Release of Non-Exchangeable NH_4^+ in Flooded Paddy Soils

作     者：ZHANGYong-Song SHAOXing-Hua LINXian-Yong H.W.SCHERER ZHANG Yong-Song1, SHAO Xing-Hua1, LIN Xian-Yong1 and H. W. SCHERER2 Ministry of Education Key Lab of Environmental Remediation and Ecosystem Health, College of Natural Resources and Environmental Science, Zhejiang University, Hangzhou 310029 (China). 2Institute of Plant Nutrition, university of Bonn, Karlrobert-Kreiten-Str, 13, D-53115 Bonn (Germany)

作者机构：MinistryofEducationKeyLabofEnvronmentalRemediationandEcosystemHealthCollegeofNaturalResourcesandEnvironmentalScienceZhejiangUniversityHangzhou31002g（China） InstituteofPlantNutritionJniversityofBonnKarlrobert-Kreiten-Str13D-53115Bonn（Germany） 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2005年第15卷第3期

页      面：273-280页

核心收录：

学科分类：0818[工学-地质资源与地质工程] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 090301[农学-土壤学] 

基　　金：Project supported by the National Natural Science Foundation of China (No. 30070428)  the Research Foundation ofGermany  the Zhejiang Province Natural Science Foundation (No. 399485) and the Foundation for University PhD GrantingDiscipline by the Ministr 

主　　题：ammonium release exchange resin non-exchangeable ammonium paddy soil root exudates 

摘      要：In a model experiment, which imitated the rhizosphere of rice, the effect of organic acids (oxalic acid, citric acid) and protons on the release of non-exchangeable NH4+ and the resin adsorption of N was studied in a paddy soil, typical for Zhejiang Province, China. Oxalic and citric acids under low pH conditions, in combination with proton secretion, favored the mobilization of NH4+ ions and increased resin adsorption of N. The release of non-exchangeable NH4+ was associated with less formation of iron oxides. These could coat clay minerals and thus hinder the diffusion of NH4+ ions out of the interlayer. Protons enhanced the release of NH4+, and then they could enter the wedge zones of the clay minerals and displace non-exchangeable NH4+ ions.