Vol. 7, Issue 10, Part B (2025)

Soil-plant nutrient interactions are critical for sustaining productivity and soil health in intensive potato-based cropping systems, where heavy nutrient demand and short crop duration often lead to nutrient mining and soil organic matter depletion under sole mineral fertilization. This field experiment, conducted over two seasons in a sandy loam Inceptisol under irrigated conditions, evaluated the effects of organic-inorganic fertilizer combinations on soil fertility, tuber yield, nutrient uptake and nutrient-use efficiency. Six nutrient management treatments were compared in a randomized complete block design: unfertilized control, 100% recommended dose of fertilizer (RDF), 75% RDF + farmyard manure (FYM) @ 10 t ha⁻¹, 50% RDF + FYM @ 15 t ha⁻¹, 75% RDF + compost/vermicompost @ 5 t ha⁻¹, and organics alone supplying the full N requirement. Post-harvest soil samples (0-15 cm) were analyzed for soil organic carbon (SOC) and available N, P and K; plant samples were analyzed for NPK uptake, and tuber yield, size-grade distribution, dry matter and specific gravity were recorded. Integrated nutrient management (INM) treatments significantly increased SOC and available N, P and K over both control and 100% RDF, with the highest values under 50% RDF + FYM and 75% RDF + compost/vermicompost. These treatments also produced the greatest total and marketable tuber yields, with higher proportions of large and medium tubers, and showed marked improvements in N, P and K uptake. Nitrogen-use efficiency indices, including agronomic efficiency, apparent recovery and partial factor productivity, were consistently superior under INM compared with sole RDF, while organics alone showed intermediate performance. Strong positive relationships between SOC, nutrient uptake and tuber yield underscored the pivotal role of soil organic matter in driving system performance. Overall, the results demonstrate that appropriately balanced organic-inorganic fertilizer combinations can enhance soil fertility, increase yield and improve nutrient-use efficiency, providing a practical pathway toward sustainable intensification of potato-based cropping systems.