The Solid Surfaces in Submerged Soils

As a rule of thumb, at near neutral pH, each g of organic C per kg of soil increases the surface negative charge by about 3 cmolckg soil. 

A further complication is that soil organic matter becomes more soluble at higher pH as dissociation increases the surface negative charge. Also, organic matter may form coordination complexes with some metals involving covalent bonds. 

Many submerged soils are developed in recent in alluvium and are often young or only weakly weathered (Section 1.3). The overall composition of the clay fraction is therefore often close to that of the parent sediment. Hence the following generalizations can be made for rice soils in the humid tropical lowlands (Kyuma, 1978 Binkman, 1985) 

Various changes in mineralogy are induced by seasonal flooding. The first factor in this is the change in base status of the soil due to the flow of water 

Interchange of Solutes between Solid, Liquid and Gas Phases 

---