Management practices of macronutrients for potato for smallholder farming system at alluvial soil (Entisols) of India

In the present study, seven fertilizer treatments [T-1, 50% NPK; T-2, 100% NPK (Recommended dose of fertilizer, 200-65.4-124.5kg N-P-K ha(-1)); T-3, 150% NPK; T-4, 100% PK; T-5, 100% NK; T-6, 100% NP and T-7, control (zero NPK)] with four replications were assessed in the new alluvial soil zone (Entisols) of West Bengal, India. The objectives of the study were to generate information on potato productivity, profitability, indigenous nutrient supply and net gain/loss of NPK in post-harvest soil. Plants grown under higher NPK supply resulted in higher tuber yield and there were significant (p0.05) reductions in total yield with nutrient omissions. Nutrient-limited yields were 19.78, 2.83 and 1.77 t ha(-1) for N, P and K, considering total tuber yield (28.24 t ha(-1)) obtained under 100% NPK as targeted yield. Indigenous nutrient supply of N, P and K were estimated at 24.1, 22.34 and 110.22kgha(-1), respectively that indicates higher K-supplying capacity of experimental soil as compared to N and P. Net income (US$1349ha(-1) year(-1)) and B:C ratio (1.91) was highest with 100% NPK, and further addition of NPK (150%) resulted in decrease on net return (US$1193ha(-1) year(-1)) and B:C ratio (1.73).