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

This study was aimed at developing the principles of 4R Nutrient Stewardship for the rice-maize-greengram cropping system, and provide nutrient management guidelines to farmers to increase the productivity and profitability of this newly introduced cropping system. The study was conducted in Cuttack and Puri districts in the coastal agro-ecosystem, and Dhenkanal district in the rain-fed agro-ecosystem of Odisha. Four farmers from each district were selected, soils at each site were tested to identify the limiting nutrients, and a balanced fertilizer treatment (BFT) involving all the limiting nutrients was developed for each location following the principles of site specific nutrient management (SSNM). A total of 10 treatments were formulated at each location including: BFT, omission of nitrogen (N), phosphorus (P), potassium (K),sulfur (S), Zinc (Zn), boron (B), and lime from BFT, a control, and farmers' fertilizer practice (FFP).

In Cuttack, averaged over two years, the grain yield of rice from the BFT was 3.9 t/ha, which was 30% higher than the yield in FFP and double that of the control. Yield reduction due to omissions of N, P, K, S, B, Zn, and lime were 48, 17, 16, 26, 37, 29, and 24%, respectively. Similarly, in the Puri district, the average grain yield of rice due to BFT was 5.8 t/ha, which was 36% higher than the yields obtained in the FFP. Practicing 4R principles of nutrient management improved the yield of rice in BFT. The highest maize (6.5 t/ha) and green gram (0.9 t/ha) yields were recorded in the BFT. Comparing rice-equivalent yield of the rice-maize-green gram cropping system, the highest system yields of 13.4 t/ha were recorded with BFT, which was 73% higher than FP. Similarly, during the second year, rice equivalent yield of rice-maize-green gram cropping system was 14.9 t/ha, which was 39% higher than FP. The total N, P, and K uptake of the entire rice-maize-greengram cropping system was 294, 68, and 253 kg/ha, which was higher than FP by 58, 57, and 37%, respectively. Also, the apparent recovery of N, P, and K with BFT was 64, 77, and 120%, which was higher than FP by 100, 196, and 56%, respectively. Use of BFT, based on 4R guidelines, resulted in improved yield for the rice-maize-greengram cropping system.