渍水土壤还原过程对土壤结构的影响研究综述

综述了渍水土壤还原过程中微生物代谢、化学变化、土壤结构和土壤胶体的稳定性的相关研究 .在还原过程中 ,随着好氧细菌、兼性厌氧细菌、硫酸还原菌和甲烷菌的活动 ,相继形成氨、硝酸根离子、亚铁离子、硫化物、气体物质及有机酸 .在渍水初期 ,水溶性阳离子浓度的增加导致土壤悬浊液凝集 .在渍水后期 ,亚铁沉淀的形成致使二价水溶性阳离子浓度降低 ,使得土壤胶粒悬浊液分散 .在还原条件下 ,土壤胶体稳定性的变化过程是一个动电机理 .

A Review of Researches on Soil Structure in Relation to Reduction Process in Submerged Soils

The review summarizes the microbial metabolism, chemical transformations, soil structure, and colloidal stability with reference to the reduction process in waterlogged soils. Ammonia and nitrate, ferrous ion, sulfide, various gases and organic acids are sequentially formed, corresponding to the activities of aerobic and facultatively anaerobic bacteria, sulfate reducing bacteria, and methane producing bacteria with the development of reduction reactions. The increase of water soluble cations leads to the flocculation of soil suspensions in the earlier period of waterlogging. The formation of ferrous precipitates in the later period of waterlogging causes the decrease in the concentration of divalent water soluble cations and the dispersion of soil colloidal suspensions. The changes of soil colloidal stability under reduction conditions have been demonstrated to be the electro kinetic mechanism.