Assessment of Soil Fertility through Response of Rice (Oryza sativa L.) to Nutrient Omission in Alfisols of Kondagaon District of Chhattisgarh in India

The investigation was carried out with the aim to identify the specific yield limiting nutrients through response of rice to nutrient omission in pot culture under completely randomized design with 3 replications and 11 treatments during kharif season 2017 and to demonstrate the optimum use of identified limiting nutrients in wheat crop at field level in Kondagaon district during rabi season 2017-18. The treatments were formulated by keeping one treatment with application of all nutrients in optimum level and others by sequentially omitting each nutrient. The soil had a clay loam texture, neutral reaction (pH 6.6), normal electrical conductivity, medium organic C, available P and K, low available N and S, high available Ca, Mg, Fe, Mn and Cu and marginal available Zn and B. Omission of N and P nutrients significantly reduced the growth, yield and nutrients uptake by rice in comparison to all nutrients. The maximum grain yield of 73.0 g pot-1 was recorded, in all nutrients pot and 50.1 % reduction in grain yield of rice, from the maximum yield, was recorded in N omitted pots, followed by 18.8 % reduction in P omitted pots and omission of other nutrients didn’t reduce the grain yield significantly indicating that only N and P were yield limiting nutrients. In field verification during rabi season, 19.0 % increase in wheat grain yield and 23.0 % increase in net return was recorded, due to optimum dose of identified yield limiting nutrients over farmer's practice dose. The results clearly indicate that the site specific nutrient management dose based on yield limiting nutrient identified through nutrient omission study was found economically profitable to the farmers.