Advances on the study of mineral-humus interactions in soils

Interactions of humus,oxides and clay mineras mainly include anion exchange,ligand exchange surface complexing,hydrophobic interaction,entropic effects,hydrogen bonding,cation bridging and electrostatic interaction.The properties of humus,oxides,clay minerals,pH value and ion strength are the major factors influencing mineral-humus interactions.The specific surface areas,surface acid-base properties,surface site densities,surface charge of minerals and the total acidity,COOH groups,total OH groups,C=O groups,NH2 groups,aromaticity,humidity,molecular weight of humic acids would substantially affect the adsorption between humic acids and minerals.Adsorption amount would increase with the pH decreasing but with the ion strength increasing.In this paper,the advances on the study of mineral-humus interactions and influencing factors in soils are reviewed.