Evaluating Principles of 4R Nutrient Stewardship in the Rice-Maize-Green Gram Cropping System for Improved Productivity and Profitability of Farmers in Odisha

Rice has been a traditional crop in the state of Odisha and is grown under rainfed lowland conditions, covering over 53% of the gross cropped area (8.4 million ha) in the state. The cropping intensity in Odisha is quite low in comparison to the other states of India and most parts of the state do not grow any second crop following rice harvest. Crop intensification has immense prospects to overcome uncertainties in single-crop rice areas of Odisha. Therefore, a study exploring the feasibility of accommodating succeeding crops like maize or green gram in sequence with rice was planned for ensuring sustainable crop productivity and soil fertility in the region. Also, developing principles of 4R Nutrient Stewardship in this newly proposed cropping system would provide nutrient management guidelines to farmers and help sustain the productivity and profitability of farmers practising this cropping system. Cuttack and Puri districts in the coastal agroecosystem and Dhenkanal district in the rainfed agroecosystem were chosen for this study. Four farmers from each district were selected and a high yielding rice variety was grown during the monsoon season of 2013 with a set of 10 treatments. The experimental treatments were formulated based on the results of the initial soil analysis. A total of 10 treatments were used at each location, viz., balanced fertilizer treatment (BFT) that included lime application, omissions of N, P, K, S, Zn, B, or lime from BFT, one absolute (unfertilized) control, and one farmers' fertilizer practice (FFP).

In Cuttack, the grain yield of rice from the BFT was 3.5 t/ha, which was 27% higher than the yield in FFP and 165% higher than the control. Yield reduction due to omissions of N, P, K, S, B, Zn, and lime were 64, 19, 12, 35, 61, 46, and 32%, respectively. Similarly, in the Puri district, grain yield of rice due to BFT varied from 4.6 to 5.8 t/ha, with an average of 5.1 t/ha. This was 33 and 72% higher than the yields obtained in the FFP and control plots, respectively. At present, the post-harvest soil analysis and plant analysis for nutrient uptake are underway. Maize was sown as a succeeding crop to rice during the winter season at all the locations using the Nutrient Expert® program to estimate the attainable yield targets for each location and calculate the BFT. Green gram will be sown as a third crop in the system and will be grown completely on residual fertility.