Document Type : Research Paper
Authors
Abstract
This research was aimed to determine the rangeland suitability for sheep grazing in Chahtalkh-Sabzevar rangelands using FAO (1990) method. Initially, the DGN maps, including six sheets of 1:25000, topographic map of 1:50000, and geological map of 1:100000 of the study area were prepared and the vegetation types were detected. In each vegetation type, range condition, range trend and production were determined to produce the production suitability map. Then, the soil erosion sensitivity map was prepared using EPM method. To study the suitability of water, water sampling was done and the quantity of water was determined. Water samples were transferred to the laboratory to measure TDS, EC and Mg+2 for each sample. Finally, the suitability map of water resources was produced by combining the layers (provided for four slopes including 0-10%, 10-30%, 30-60% and >60%). The final model of rangeland suitability was prepared by overlaying the maps of production suitability, soil susceptibility to erosion and water. According to the obtained results, there is no suitability S1 class in the region and 23.7%, 18.92%, and 56.9% of the study area have S2, S3, and N suitability classes, respectively. Generally, it can be said that the conversion of rangeland to dryland, overgrazing and early grazing, formations susceptible to erosion, low vegetation cover, salinity, and improper distribution of drinking water sources for livestock are considered as the most important limiting factors for sheep grazing.
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