Efficacy of nano fertilizer application to groundnut in rice-groundnut cropping system

An experiment was conducted at the Agronomy main research farm, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar, during the Kharif and Rabi seasons of 2022–23 and 2023–24. The research was worked out in randomized block design (RBD) during kharif and split plot design (SPD) during rabi. The rice variety “Kalinga Dhan 1204” was transplanted in kharif with seven treatments: T1- Control (no fertilizer), T2- full soil test based nitrogen recommendation (STBNR) through inorganic sources, T3- full STBNR through organic sources (FYM), T4- full STBNR through 50 % organic (FYM) + 50 % inorganic sources, T5- full STBNR through 25 % organic (FYM) + 75 % inorganic sources, T6- 50 % N through inorganic sources + 2 nano urea spray (tillering & PI stage), T7- 75% N through inorganic sources + 2 nano urea spray (tillering & PI stage). During rabi season each main plot divided into 3 sub plots and groundnut (variety- Kadiri lepakshi) was sown with 3 treatments: Z1-100 % recommended dose of fertilizer (RDF), Z2-75 % RDF+ 2 nano DAP spray, Z3- 75 % RDF+ 2 nano di ammonium phosphate (DAP) spray + Phosphorus solubilizing bacteria (PSB). Pooled data revelled that highest number of panicles per square meter (393.17), total number of grains per panicle (176.83), test weight (25.27), grain yield (6.64 t ha-1), straw yield (7.45 t h-1) and harvest index (47.13 %) of rice were obtained with full STBNR (25 % organic (FYM) + 75 % inorganic). Among different treatment combinations, highest system yield (13.85 t rice equivalent yield ha-1), system gross return (Rs. 303807), system net return (Rs. 164039) and system B/C ratio (2.17) were obtained with T5Z3 combinations.