Influence of gully erosion on soil moisture of abandoned farming dry land and rangeland in loess land (Case study: Kale-Shour watershed, Golestan Province)

Increased soil dryness of hillsides and lands around the gully causes the aggravation of the gully erosion which leads to the desertion of the environment. Soil moisture contents are various in different soil depths, gully positions, and in various land uses. These are fundamental for ecosystem sustainability in arid and semi-arid area. Therefore, understanding the behavior of soil moisture in dry and critical periods is necessary for gully erosion management based on biological conservation and restoration of vegetation around the gully. Thus, in this research two typical gullies were chosen, one in abandoned dry farming land and another one in the rangeland. Soil samples were taken from the land around the headcuts, 50% of the length and the end of the gully at the wall locations, and 200 and 500 cm away from the edge of the gully, and from two different depths; surface (0-30 cm) and subsurface soil (30-100 cm) in summer (once every fifteen days), and soil moisture of samples were determined. The results showed that soil moisture content increased with increased distance from the edge of the gully, and also by increased depth around gully in the both mentioned land uses. Simultaneously, the average soil moisture in the gully of the rangeland was greater than in the gully of the abandoned farming dry land. In summary, it is safe to say that rangeland of loess land plays an effective role to prevent soil moisture evaporation which is the result of the gully erosion.