Dinesh Khadka1, Sushil Lamichhane1, Binita Thapa1, Ram B. K.C.2 Buddhi B. Pant1, Sirjana Phuyal1 and Laxman Lakhe1
1Soil Science Division, Khumaltar
2Nepal Agricultural Research Council, Singhadurbar Plaza
Abstract
A study was conducted to examine and map the soil fertility status of the Horticulture Research Station, Malepatan. The research farm is situated within latitude 28°13'07"N and longitude 83°58'21"E at altitude 850 m above sea level. Forty samples were collected randomly at depth 0-20 cm. A GPS device was used to identify the location of the soil sampling points. Soil Samples thus collected were analyzed for their texture, pH, OM, N, P, K, Ca, Mg, S, Zn, Fe, Cu, Mn and B status following standard methods in the laboratory of SSD, Khumaltar. The soil fertility status maps of each nutrient were prepared using ArcGis 10.1 Software.Evaluation of data showed that the soil was silt-loam, very acidic to moderately alkaline in pH (4.4- 7.6) and very low to high in Organic Matter (0.50-7.2%). Regarding the macronutrients; low to high total N (0.05 - 0.23%), very low to very high available phosphorus (6-71OKg ha-1), Very low to medium extractable potassium (13- 260 Kg ha-1), low to high extractable calcium (96-2470 ppm), low to medium extractable magnesium (27.8 -131.8 ppm) and very low to high Sulphur (1- 16.6 ppm) were observed. Likewise, the status of micronutrients was low to high in DTPA-Zinc (0.8-7.7 ppm), The specific locations of various soil sampling points were determined using Global Positioning low to very high in DTPA- Iron (8.7-47.1ppm), medium to very high in DTPA-Copper (0.9-7.5ppm), very low to high in DTPA-Manganese (2.3-18.9ppm) and very high in hot water Boron (2.3 -5.9ppm). The overall assessment of the research farm revealed very high variation on the fertility status, which might be due to the heterogeneity on the management practices for various research purposes within the farm. Looking upon this variation in fertility status, application of the fertilizer dose to each crop based on the soil test rather than on a blanket approach is suggested to make research works more reliable and the farm management more efficient and sustainable. Nutrient categories portrayed on the prepared soil fertility maps can serve as an important aid in this regard
Keywords: ArcGIS, Global Positioning system, Soil fertility status and Soil fertility Maps