Soil air-water properties in Catena of Sepopol Lowland

In the sequence of soil composed of black earths, deluvial soils, organic soils covered with a thin layer of mineral-organic deposit and moorsh soils, soil texture, bulk density, content of organic carbon and organic matter, total porosity, total and readily available water as well as resources of organic matter and water in 0-25 cm and 0-100 cm layers of the soil profile were studied. A catenal variabilities of organic matter content and physical-water properties were found. Physical properties and the contents of total and readily available water depended on soil texture, organic matter content and location in a relief. Total porosity, field water capacity and volume of macropores were positively correlated with organic matter content, and negatively with bulk density. Differences in studied properties between the pedons of black earths and deluvial soils were small, whereas these differences between deluvial and moorsh soils were distinct. In the development of water resources in the profiles of these soils, presence of organic subsoil with high retention capacity played the important role. The studied soils had unfavorable distribution of soil pores, resulting from a small volume of air pores.