Abstract:

The present research work was carried out in surface soils (0- 15 cm) of North Saurashtra Agro-Climatic zone at Junagadh Agricultural University, Junagadh, Gujarat, India in the year 2021-2023. The soils were extending between 210 0’0” to 230 30’0” North latitude and 690 30’0” to 720 30’0” East longitude. The soils ranged from Shallow medium black to medium black calcareous, whereas soils developed by basalt, rocks, and sandstone deposit. A total of 480 soil samples were collected using the GPS location of North Saurashtra Agro-Climatic Zone and then after potassium fractions were evaluated. This involved status of water-soluble K, available K, exchangeable K, 1 N nitric acid soluble K, total K, and reserve K as well as inter-correlation between K fractions, simple correlation and regression models of available K and map prepared by Arc GIS software with six tire data feeding denoted with six different color concentration. The status of exchangeable K (13.6-319.8 mg kg-1), 1 N HNO3 soluble K (86.0 to 1024.0 mg kg-1), water-soluble K (2.2 to 70.2 mg kg-1), total K (0.15-1.89 %) and available K (18.0 to 400.0 mg kg-1) were recorded in soils of North Saurashtra Agro-Climatic Zone. The following was the order of abundance of soil fractions in the soils: Total K >1 Normal (nitric acid soluble) HNO3-K > reserve K > available K > Ex-K > water-soluble K. About 6.45 percent of samples were tested as the low class (< 55 mg kg-1), 53.75 percent of samples were under medium class (55-125 mg kg-1) and 39.40 percent of samples falls in the high available potassium class (> 125 mg kg-1). Furthermore, it referred to a high nutrient index rate (NI≥2.33).