Hydromorphic Soils

Abstract

Prolonged water saturation and seasonal alternational between water logging and drainage has profound effects on soil chemical and morphological properties. Changes in the degree of water saturation affect the supply of O₂ to the soil, wich in turn affects the oxidation state of important elements. The oxidation state of iron, manganese and sulfur strongly influences their solubility and colour, explaining the brown, gray, blue, black and yellow mottles often seen in periodically wet, so-called hydromorphic, soils. Redox processes often involve production or consumption of H⁺ and so have an important effect on soil pH too.