Bundled management practices for enhanced Finger millet productivity in acid soils: Empirical evidence from Odisha, India

Context: Odisha is one of India's major finger millet-growing states; however, the crop's yield is negatively impacted by climate change-related phenomena like drought, flooding, soil erosion, and soil acidity. Approximately 30 % of global soils are acidic, which reduces millet productivity due to low base saturation and toxic metals. Therefore, adopting bundled management practices, viz., improved variety, soil test-based fertilizer recommendation (STBF), and integrated pest management (IPM), hold the key to sustainably enhancing the finger millet productivity in the acid soils of Odisha, India. Objective: The overall objective of the study was to develop recommendation domains for finger millet by evaluating various bundled management practices in acid soils in relation to grain yield, rainwater use efficiency (RWUE), system productivity, and economics, as well as to understand the correlation between soil nutrients and grain yield. Methods: The on-farm study was conducted in two districts of Odisha, viz. Gajapati and Koraput, under a collaborative project between Odisha Livelihoods Mission (OLM), Govt of Odisha, and International Crops Research Institute for the Semi-Arid Tropics, Hyderabad during 2020 and 2021. The study involved six treatments: 1) Improved variety (IV), 2) IV + IPM, 3) IV + STBF, 4) Local variety (LV), 5) LV + IPM, and 6) LV + STBF. Results: The bundled management practices led to a higher finger millet yield in both years and contributed to improved system productivity in the acid soils of Odisha. Compared to the LV, the finger millet yield was higher by 21.92 % and 39.46 % with IV + IPM and 68.06 % and 78.05 % with IV + STBF in 2020 and 2021, respectively. The highest RWUE was observed when IV was bundled with IPM (44 %) and STBF (33 %). The Agronomic nitrogen use efficiency (ANUE), system productivity, net monetary return (NMR), and benefit: cost ratio were higher in the STBF and IPM treatments, regardless of improved or local cultivar. The regression analysis of the yield of IV + STBF with organic carbon, sulphur, zinc, and boron presented that for every 1 % increase in these elements, there will be an increment of finger millet yields by 222, 7.6, 55, and 343.9 kg ha−1, respectively. Overall, the bivariate analysis showed that IV, combined with STBF, is clustered in the top-right quadrant, indicating high productivity and profitability, making it the most promising bundled management practice. Conclusion: Bundled management practices, including IV combined with IPM and STBF, could be an effective adaptation strategy to enhance finger millet grain yield, RWUE, ANUE, system productivity, and the economic benefits for smallholder farmers in the acid soils of eastern India. Implications: This study contributed to developing bundled management practices for sustainably increasing finger millet productivity under climate change scenarios and recommends scaling up these practices through government agricultural policies in the acidic soils of Eastern Indian states like Odisha.