Effect of seed rate and integrated nutrient management on growth, yield and economics of direct seeded hybrid rice (Oryza sativa)

Abstract

A field experiment was conducted during the rainy seasons of 2016 and 2017 at Agricultural Research Farm, Banaras Hindu University, Varanasi, Uttar Pradesh, to evaluate the effect of integrated nutrient management and seed rate on growth, yield and economics of direct-seeded hybrid rice (Oryza sativa L.). The treatments comprised 3 seed rates (16 kg, 20 kg and 24 kg/ha) and 5 nutrient management, i.e. 100% recommended dose of fertilizer (RDF) through inorganic fertilizer, 100% RDF through inorganic fertilizer + ZnSO .7H O 25 kg/ha followed by (fb) 4 2 0.2% FeSO and 0.2% Borax foliar spray at 20 and 40 days after sowing (DAS), 75% recommended dose of nitro- 4 gen (RDN) through inorganic fertilizer + 25% N through FYM, 50% RDN through inorganic fertilizer + 50% N through FYM, and 75% RDN through inorganic fertilizer + 25% N through vermicompost. The experiment was laid out in split plot design with 3 replications. Rice hybrid sown at seed rate of 20 kg/ha showed superior performance in respect of tillers/m2, dry-matter accumulation, leaf-area index (LAI), soil plant analysis development (SPAD) value and yield parameters, i.e. grain and straw yields, net returns and benefitcost ratio as compared to seed rate of 16 and 24 kg/ha. Amongst the integrated nutrient management options, an application of 50% RDN by urea + 50% N by FYM resulted in better performance, being comparable with those of 75% RDN through inorganic fer- tilizer + 25 % N through FYM. However, 100% RDF through inorganic fertilizer recorded the lowest growth and yield parameters. Seed rate of 20 kg/ha along with 50% RDN through inorganic fertilizer + 50% N through FYM was found to be a better option for obtaining optimum crop plants and nutrient-management practices in direct- seeded hybrid rice.