Impact assessment of land use change from rain-fed agriculture to rangeland by floodwater spreading on some physical-chemical characteristics of soil in the Razin area of Kermanshah province

Protection, restoration, development, and optimal use of soil, especially in natural areas such as forests, pastures, deserts, and natural groves, for sustainable development, are possible through scientific and comprehensive management. In the present research, some physical and chemical properties of soil were investigated in two locations reclaimed wetlands through flood spreading operations and the control area (degraded wetlands). In both places, 16 profiles were dug and due to two sampling depths of 0-25 and 25-50 cm, 32 soil samples were collected. In the samples, the percentage of silt, clay, sand, permeability, electrical conductivity (EC), soil acidity, absorbable iron, manganese, zinc, phosphorus, potassium, percentage of carbon and organic matter were measured. Then, the average of mentioned characteristics was compared using the T-test between the two restoration areas and the degraded control area at the level of 5% and 1%. According to the results the difference between the two places in the first depth of 0-25 cm, was more evident, so in the first depth between the two places in terms of silt, clay, sand, permeability, apparent specific gravity, electrical conductivity and cation exchange capacity and percentage of organic matter, soil carbon, absorbable phosphorus, iron, zinc, and manganese there is a statically significant difference at the 95% level (P≤0.05). It was also found that the percentage of soil organic matter and carbon increased significantly and the permeability of the soil decreased significantly at the level of 95% with the implementation of flood spreading restoration operations. Also, the results showed that in the control the rain-fed amount of soil phosphorus was higher which can be explained by the continuous fertilization of phosphate fertilizers by the farmers in the degraded rain-fed lands.