Evaluation of Soil Quality Based on Minimum Data Set in Karvan Rangeland, Isfahan, Iran

Plant life and food production for human closely depend on fertile and healthy soil. Knowledge about qualitative properties of soil and its potential production can contribute us in the plantation, fertilization, utilization and land management. In addition, Rangelands cover a very large portion of the earth's surface and play an important role in food security and other ecosystem services. Therefore, the present study has been conducted in order to evaluate soil quality according to minimum data set in Karvan rangeland which is located in the west of Isfahan province, Iran. For this aim, three vegetation types including Scariola orientalis-Astragalus gossypinus (Sc.or-As.go), Psathyrostachys fragile-Astragalus gossypinus (Psa.fr-As.go) and Cousinia bachtiarica-Astragalus gossypinus (Cu.ba-As.go)were selected in the study area. Then, four transects were established by a random systematic sampling; bias was placed to the general and lateral slope at the each vegetation type. The soil samples were taken at the start and end of each transect from two different depths (0-20 and 20-75 cm). Soil samples were analyzed and the physicochemical factors such as texture (silt, clay and sand), pH, Nitrogen (N), Phosphorus (P), potassium (K), Organic Carbon (OC) and Organic Matter (OM) were measured. Then, Soil Quality (SQ) indices were calculated using Bajracharya formula. The results showed that soil of the study area had a poor quality and also, there was different soil qualities regarding three vegetation types. It was found that OC (or OM) and N had maximum limitations on soil of Karvan region and caused low SQ indices. Also, pH only without any limitations was put in the highest rank for SQ measuring.