Study on Integrated Effect of Inorganic Fertilizers and Organic Manure on Available Nutrients, Yield and Nutrient Uptake in Scented Rice

Field experiments were conducted at the Instructional-cum-Research (ICR) Farm, Assam Agricultural University, Jorhat during the year 2017 and 2018 to study the integrated effect of inorganic fertilizers and organic manure on available nutrients, yield and nutrient uptake in scented rice. Before the test crop experiment, fertility gradient experiment was conducted by using kharif rice (cv. Ranjit) as an exhaust crop to create three fertility gradient strips. After harvesting the gradient crop, test crop experiment was conducted in the same field with scented rice (cv. Keteki joha) by superimposing 24 combination treatments consisting of five levels of N (0, 10, 20, 40 and 60 kg ha-1), four levels of P2O5 (0, 5, 10 and 20 kg ha-1), three levels of K2O (0, 10 and 20 kg ha-1) and three levels of vermicompost (0, 2 and 3 t ha-1) in each of these fertility gradient strips. Results show that application of integrated nutrient management approach brought about a positive influence on organic carbon, nutrient availability, crop yield and nutrients uptake by scented rice. Combined application of 60 kg N, 10 kg P2O5 and 10 kg K2O per hectare along with 3 tons of vermicompost per hectare resulted in the highest concentration of available NPK in soils, the highest crop yield and uptake of nitrogen, phosphorus and potassium by rice.