Effect of Rangeland Conversion to Dryland Farming on Soil Chemical Properties (Case study: Kian rangelands, Lorestan, Iran)

Land use change as the most important destructive factor in natural ecosystems is a globally problem that changes soil properties. Therefore, correct management and recognition of change aspects on each component of the ecosystem is necessary. This process causes land destruction, ecosystem instability, soil erosion, and more biological threats. Due to increasing land use conversion from rangelands to dryland farming, the effect of this phenomenon was studied on soil chemical properties in three land uses such as protected rangeland, dryland farming and abandoned dryland in Kian rangelands in Lorestan province, Iran in 2016. Soil properties including Soil Organic Carbon (SOC), pH, Electrical Conductivity (EC), and lime were compared between three land uses in two depths of 0-20 cm and 20-50 cm. Results showed that land use changes significantly affect these soil properties. In dryland farming, SOC was reduced in comparison to rangeland by 42% and 52% in the first and second depths, respectively. In contrast, the pH, EC and lime values were increased more than natural rangelands as 0.9%, 25.8%, 63.1% in the first depth, and 0.4%, 50%, 15.1% in the second depth, respectively. By stopping farming in abandoned dryland, the soil properties in abandoned dryland, were closer to rangeland than soil properties in dryland. These amounts in abandoned dryland ranked between rangeland and dryland farming. Our findings revealed that soil chemical properties were changed by conversion of rangeland to dryland farming via agricultural activities and human manipulation. Regarding these effects on soil properties and to keep ecosystems stability, attention has to be paid to land capability and prevention from wrong land uses.