Evaluation of the Effectiveness of Pasture Restoration Projects Based on Soil Stability Indicators in Arid Ranglands (Case study: Yazd province)

The stability of the soil structure shows the ability of the soil to resist erosive forces and rebuild after destruction. Considering that the soil is one of the important components of the rangland ecosystem, it is important to maintain its stability. The purpose of this study was to investigate the effect of range restoration activities on soil stability was using seven-factor, scoring and Emerson indices in ranglands of the Yazd province, evaluate these indices, and provide a suitable and compatible method for rangland. For this purpose, first among the biological and biomechanical projects implemented in the ranglands of the province, the Crescent water catchment, Furrow and Contour Trenching, were selected in three traditional systems. Sampling of soil and vegetation was done using systematic-random method with the establishment of transect and plot. In order to compare the effects of different reclamation methods on soil stability indicators by entering the data into the SAS environment, nested variance analysis was used. Then, by using Statgraphics software, the relationship between soil factors and vegetation was investigated and the classification of soil stability for the studied ranglands was done. The results showed that all soil parameters, except organic matter and lime, have significant differences in the studied areas. The most important soil parameters affected by remediation include SAR, ESP, pH, sodium, calcium and magnesium content with special values ​​of 0.30036, 0.30035, 0.2928, 0.2907, 0.2898 and 0.2894, respectively. Considering that the soil of the studied areas was mostly sandy, sandy-loamy and loamy-sandy, it did not agree with the textures mentioned in the classes of the seven-factor soil stability index. So this index was not suitable for determining soil stability. On the other hand, the algebraic sum index of four soil factors and Emerson's method can not show the changes of soil stability within each region (control, intra-operation and inter-operation) well. Finally, the classification method of soil stability in arid ranglands was proposed based on the results of this research.