Spatial Assessment of Soil Fertility and Soil-related Constraints at KVK Farm, Sakhigopal, Puri, Odisha, India
This study assessed the physicochemical properties and nutrient status of soils at the Krishi Vigyan Kendra (KVK) farm, Sakhigopal, Puri district, Odisha, using GPS- and GIS-based soil fertility mapping to identify site-specific soil-related constraints and develop appropriate nutrient- and land-management strategies. A plot-wise soil survey was conducted using 35 GPS-referenced composite surface soil samples (0–15 cm) collected from upland (plots 1–5), medium land (plots 6–15), and lowland (plots 16–35) physiographic units. Samples were analysed for texture, pH, electrical conductivity (EC), soil organic carbon (SOC), available nitrogen (N), phosphorus (P), potassium (K), and sulphur (S) using standard analytical procedures. Geographic coordinates and laboratory data were integrated in ArcGIS to generate thematic soil fertility maps. Soil texture ranged from sand to sandy loam, with mean clay content decreasing from upland (8.80%) to medium land (7.72%) and lowland (7.04%). Soil pH ranged from 5.00 to 7.13, with a mean of 6.53, while EC values ranged from 0.05 to 0.60 dS m⁻¹, indicating non-saline conditions throughout the farm. SOC ranged from 3.2 to 10.3 g kg⁻¹ and increased down the toposequence, from 3.2–4.7 g kg⁻¹ in uplands to 8.3–10.3 g kg⁻¹ in lowlands. Available N (173–260 kg ha⁻¹) and P (5.6–24.5 kg ha⁻¹) were low to medium, K (115–535 kg ha⁻¹) was medium to high, and S (2.2–7.3 kg ha⁻¹) was predominantly low. The principal soil-related constraints were sandy texture and low clay content, low SOC and acidity in uplands, widespread sulphur deficiency, upland erosion, and waterlogging in lowlands. Based on the observed soil physicochemical and nutrient status, the study suggests physiography-based land use, organic-matter enrichment, need-based liming, sulphur supplementation, and soil-test-based site-specific fertiliser management as potential strategies to improve nutrient-use efficiency and support long-term soil health.