Evaluation of soil quality through simple additive soil quality index (SQI) of Tehsil Charsadda, Khyber Pakhtunkhwa, Pakistan

In the study, the Simple Additive Soil Quality Index (SQI) is used to evaluate soil quality in Tehsil Charsadda, District Charsadda, Pakistan. Organic matter (OM), electrical conductivity (EC), phosphorus (P), acidity and basicity (pH), estimated nitrogen (EN), and soil texture were the parameters evaluated. The whole research region was split into 1*1 km grids for data collection, and samples were gathered from each grid along with XY coordinates. An augur was used to collect 172 samples from a depth of 30 to 45 cm. The collected samples were analyzed at the Agriculture Department in Charsadda. The index value for each soil quality indicator was determined, and then normalization was performed. Each SQ parameter was assigned a threshold value based on expert judgment and a review of the literature. The index values of each SQ parameter were added up to determine the SQI value. Using the Simple Additive Soil Quality Index (SQI), the area under poorly fertile soil accounts for 4835.52 ha (10.91%), moderately fertile soil accounts for 11853.90 ha (30.33%), and highly fertile soil accounts for nearly half of the research area (17338.1 ha (48.27%). The exceptionally productive soil is located in a large patch along the western boundary of the study area. Patches of poor fertile soil are generally found in the central, northern, and northeastern parts of the study area.