The Influence of Organic Matter and Clay Minerals on Size of Surface Area of Different Peptization Level in the Meadow Soil of the Middle Priamurje, Russia

摘要

The studied soil was the meadow podbel (planosol in the FAO system), periodically over moistured with atmosphere precipitation. The soil profile revealed well-marked genetic horizons. Soil clay (particles < 2 μm) was sequentially divided into water-peptizable (WPC) and aggregated (AC) sub-fractions according to their ability to peptizate in water. Specifics of the quantitative content of WPC and AC in the major horizons of this soil were determined Surface area was estimated in WPC and AC samples by adsorption of water vapor. OM content and composition of clay minerals were estimated by X-ray diffractometry. Higher (1.5-2 times) surface area of aggregated clay particles is consistent with a higher content of phyllosilicates with a swelling smectite component, humic matter and non-silicate iron. These aggregating factors are less important for particles of water-peptizable clay.