Diagnostics of Desertification with the Use of Water Retention Curve of Soils.

Based on a study of processes developed upon desertification (salinization, solonetzization, and sand accumulation) in the soils of the Caspian Sea Lowland, it is shown that soil's water retention capacity may be used as an integral parameter of all desertification trends. It is characterized by the water retention curve (WRC). The physical sense of the use of the WRC to characterize desertification consists in the fact that it shows the capability of soil to retain moisture and soil moisture mobility and availability for plants and thus characterizes the main edaphic factors, which limit biological productivity in natural ecosystems and the agroecosystems of arid regions. The soil WRC is a constant value without seasonal fluctuations, and this makes it universal in comparison with other soil parameters that undergo seasonal variations, thus making determination of the desertification rate difficult. [ABSTRACT FROM AUTHOR]