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

The current study was aimed at determining the 4R (right source, rate, time and place) guidelines in the rice-maize-greengram cropping system of Odisha. The soils of the experimental sites were loamy sand to sandy in texture, with acidic pH (4.8 to 6.9), low organic carbon (4.4 to 7.4 g/kg), low available N (155 to 190 kg/ha), low to high available P (8 to 64 kg/ha), low to high available K (30 to 140 kg/ha), low available S (8 to 12 kg/ha), low available B (0.24 ppm) and low available Zn (0.41 ppm). Based on the initial soil test results, the limiting nutrients at the experimental locations were identified and a balanced fertilizer treatment (BFT) involving all the limiting nutrients was developed as the right source. Nutrient Expert® (NE) Rice and NE Maize were used to determine the right rate of major nutrients along with the application of limiting secondary and micronutrients as per the blanket recommendation by the state government. Right time and right method of application of nutrients were followed based on the standard guidelines already established in the literature. The legume crop was grown completely on the residual soil fertility after maize without application of any nutrients.

Based on the observations, application of nutrients following the 4R guidelines in BFT resulted in 6.5 t/ha of rice yield, which was significantly higher than the farmer practice (4.7 t/ha), showing an yield advantage of 1.7 t/ha. Compared to the previous years, the grain yield of rice in BFT was improved by 35% over the results obtained in 2014 and by 46% over the year 2013, indicating that practicing 4R principles of nutrient management helped in continually improving the yield over the previous years. Currently, the 4R guidelines are being validated in maize crop and continuous efforts are made to demonstrate the benefits of practicing 4R guidelines of nutrient management with farmers in the study region. The project will be completed in 2016.