Digital soil mapping for soil fertility analysis: A case study of Rong Rural Municipality, Ilam, Nepal

Soil fertility is the important factor for the sustainability and productive ability of soil. Soil fertility is an ability to provide plant with necessary nutrients in adequate amounts, suitable forms, and appropriate proportions enabling optimal plant growth. This study was carried out to determine the soil fertility status of Rong Rural Municipality, Illam, Nepal. Altogether, 100 samples were collected randomly from the depth of (0-30 cm). The exact location of the soil samples was recorded using a GPS toolbox Application. All the samples were tested, analyzed at a soil and manure testing Laboratory, Surunga, Illam, Nepal to find out the 6 parameters of soil i.e. soil pH, soil organic matter, soil texture, available nitrogen, phosphorus, potassium status. The soil pH was tested by using Digital pH meter, soil texture by hydrometer, soil organic matter by Walkey and Black method, nitrogen by Kjeldahl Distillation unit, phosphorus by Modified Olsen’s Bicarbonate method and potassium by Flame photometer method. Moreover, soil fertility maps were made by using Arc GIS 10.5 software. Primarily the study area consists of 70.83% of sandy loam and 29.16% of loam-textured soil. The soil pH was slightly acidic ranging from 5.49 to 6.07. Soil organic matter (1.08-2.53%), nitrogen (0.032-0.24%), phosphorus (18.16-69.22 kg ha-1) was in the range. Potassium (50.39- 463.05 kg ha-1) are available in the soil with the status of low to high in the study area. To achieve sustainable crop production, it is essential to have a thorough understanding of the soil’s fertility status and implement suitable nutrient management approaches.