Effect of rainwater catchment systems on the physical and chemical characteristics of soil in dry areas (Case study: Mil Nader Region of Sistan)

The excessive use of water and soil resources, especially in arid and semi-arid regions, causes increased soil erosion, followed by the appearance of destructive floods, the emergence of dust, and intensifying the phenomenon of desertification. Therefore, in order to prevent the environmental problems of these areas, there is a need for efficient management of their water and soil resources. The rainwater catchment systems are one of the strong points of dry and desert areas, which have a high ability to develop these areas. This study investigated the effect of rain catchment systems on the physical and chemical characteristics of rainwater catchment systems soil in the Mil Nadir area of Sistan. For this purpose, six soil samples were taken from the rainwater catchment systems and the control area and their physical and chemical properties were measured. The results of this study showed that there is a significant difference of 1% between the average percentage of clay, silt, and sand in the soil of the rainwater catchment systems areas compared to the control area (P<0.01). With the increase in the percentage of clay and silt, the soil texture from class Loamy-sandy in the control area was changed to loamy class in rainwater catchment systems, which caused a 28% increase in soil moisture compared to the control area. In the examination of soil chemical properties, the findings indicate that the amount of acidity, electrical conductivity, sodium, and sodium absorption ratio significantly (P<0.01) in the soil of rainwater catchment systems decreased, but the amount of organic matter, nitrogen, and potassium increased. The effect of rain catchment surface systems has improved the physico-chemical properties of the soil, due to the existing environmental crises and the acceleration of the desertification process in this region. The use of these catchment systems in the Sistan Region provides suitable conditions for improvement. It provides ecological and environmental protection of these areas.