Indian Journal of Agronomy

An on-farm experiment involving 96 farmers (24 farmers/year) in farmers’ participatory mode was conducted during 2011–12 to 2014–15 in Mandirbazar and Kakdwip blocks of South 24 Parganas district, West Bengal to study the response of rice (Oryza sativa L.)-green gram [Vigna radiata (L.) Wilczek] cropping system to balanced nutrition. Both the crops of the experiment were treated with 7 nutrient combinations, viz. control, recommended N alone (80 kg N to rice and 20 kg to green gram), N with P (40 kg P₂O₅/ha), N with K (40 kg K₂O/ha) to both the crop, N with P+K, N with P+K+Zn (25 kg ZnSO₄) (Zn only to rice) and farmers’ practice which were replicated at 24 fields in 6 villages of the blocks. Application of 80 kg N, 40 kg P₂O₅ and 40 kg K₂O along with 25 kg ZnSO₄/ha to rice alone recorded significantly higher grain (4.51 t/ha) as well as straw (6.48 t/ha) yield of rice, while 20 kg N, 40 kg P₂O₅ and 40 kg K₂O/ha recorded significantly higher seed (0.92 t/ha) yield in the succeeding green gram. The maximum system rice equivalent yield (8.81 t/ha) and unit time system productivity (24 kg/ha/day) were also observed under balanced application of nutrients. Higher partial factor productivity (PFP) for N and K was recorded under farmers’ practice and the same for P was higher under application of N with P+K+Zn. Significantly higher net returns(46,994/ha) with cost of cultivation of 62,710/ha, B:C ratio (1.76) and sustainable yield index (0.83) were recorded with application of N with P+K and Zn to rice and N+P+K alone to greeng ram in the system. Agronomic efficiency (AE) of applied nutrients were observed to be in the order of N<NP<NK<NPK< NPKZn for rice and N<NK<NP<NPK<NPKZn for green gram.