Effect of nano DAP on growth and yield of kharif paddy (Oryza sativa L.) in Lateritic soil of West Bengal

Rice is a staple food crop vital to India's food security, yet national productivity lags far behind global leaders like China. A significant portion of applied fertilizers is lost due to inefficiencies, especially in phosphorus-deficient lateritic soils. Nano DAP, with its high nutrient use efficiency and foliar application potential, offers a promising alternative to conventional fertilizers. To evaluate this, a field experiment was conducted to study the effect of nano DAP (Diammonium phosphate) on the growth and yield of kharif paddy (variety: IET 19148) in Lateritic soil at Palli Siksha Bhavana (Institute of Agriculture) Farm, Sriniketan, Birbhum, West Bengal, India, during July to December 2021. The experiment was laid out in a Randomized Block Design with 13 treatments, including various combinations of basal DAP application, seed treatment (ST), seedling treatment (S/L T), and foliar spray (FS) using nano DAP. Treatments ranged from 0% basal DAP with full N and K (control) to partial DAP with nano DAP applications. Nano DAP was applied as seed, seedling, and foliar treatments to assess its efficiency in enhancing nutrient use and rice productivity. The highest values of growth attributes (plant height, tiller/hill, leaf area index, dry matter accumulation per square meter and crop growth rate), yield attributes (test weight, filled grain/panicle and effective tiller per square meter), grain yield (6.06 t/ha), straw yield (6.73 t/ha)) and economics, gross return (Rs.129210/ha), net return (Rs. 67801 /ha), and B:C ratio of 2.10) were recorded at treatment T10 (50% basal DAP + ST with nano DAP @ 5 mL/kg seed + FS with nano DAP @ 2 mL/L of water at 30 days after transplanting) compared to other treatments and the lowest values were recorded at treatment T1 (0% P and 0% N Basal, no basal DAP; 100% N and K). The study revealed that 50 % DAP as basal followed by seed treatment of nano DAP and foliar spray of 2 mL nano DAP/L at 25 days after transplanting, produced higher growth and yield in rice crop with high net return and B:C ratio in Lateritic soils of West Bengal.