Effect of Integrated Nutrient Management on Black Rice (Oryza sativa L.) under Rainfed Condition of Arunachal Pradesh, India

Abstract

A field experiment was carried out during the kharif season in the year 2023 at Arunachal University of Studies, Namsai, Arunachal Pradesh to assess the effect of azolla along with organic and inorganic fertilizers on the growth, yield and economics of Black rice. The experiment was laid out in Randomized Block Design with six treatments and four replications. The results revealed that application of Azolla @ 1800 kg ha-1 + NPK @ 80:30:30 kg ha-1 + Vermicompost @ 2.5 t ha-1 result in the highest number of Panicles plant-1 (11.5), panicle length (26.75 cm), number of Tillers (17.85), height (219.75 cm), Number of grain (113.50), Grain yield (3.12 t ha-1), straw yield (4.40 t ha-1) of Black rice. Transplanted Black Rice of variety khamti black rice exhibited significantly the highest gross return (₹1,29,200.00 ha-1) and cost of cultivation was ₹63,961.08 ha-1 by application of Azolla @ 1800 kg ha-1 + NPK @ 80:30:30 kg ha-1 + Vermicompost @ 2.5 t ha-1 respectively. It showed significantly maximum net ratio (₹82,081.42 ha-1) and B: C ratio (2.05) by applying Azolla @ 1500 kg ha-1 and NK @ 80:30 kg ha-1 respectively. Therefore, in the present experiment, NPK requirements are met by applying 80:30:30 kg ha-1 combined with 1800 kg ha-1 of Azolla sppalong with 2.5 tons ha-1 of vermicompost.  This approach revealed superior performance in terms of both crop yield and economic returns.