Journal of Geoscience and Eco Agricultural Studies

Abstract

India faces a growing crisis at the intersection of climate change and food security. As mean summer temperatures in semi-arid and arid regions now routinely exceed 40°C, and as rainfall variability intensifies across the Indo-Gangetic Plain, the Deccan Plateau, and the dryland belts of Rajasthan and Gujarat, the agronomic limitations of water-intensive rice cultivation are becoming increasingly untenable. Millet-based farming systems — long marginalised in post-Green Revolution agricultural policy — have re-emerged as a scientifically compelling and policy-relevant response to this challenge. This systematic review synthesises peer-reviewed empirical evidence published between 2017 and 2026 to provide a rigorous, geographically grounded comparative analysis of the climate resilience, water productivity, heat tolerance, nutritional characteristics, and policy trajectories of millet-based and rice-based farming systems in India.

Drawing on 96 primary studies and 14 foundational references sourced from Web of Science, Scopus, Sci enceDirect, Google Scholar, and institutional repositories (ICAR, ICRISAT, FAO, and IPCC), this review documents that pearl millet (Pennisetum glaucum) and finger millet (Eleusine coracana) demonstrate water productivity values of 3.8–4.2 kg grain m⁻³ — six to seven times greater than irrigated rice (0.6–1.1 kg m⁻³). Under moderate drought stress (50% water deficit), millet yields decline by approximately 25%, whereas irrigated rice yields contract by 60% or more. Heat tolerance indices confirm that millets maintain acceptable grain set rates at temperatures exceeding 38°C, a threshold at which rice pollen viability collapses. Green house gas emission intensities of millet systems (0.40–0.52 kg CO₂e kg⁻¹ grain) are five to seven times lower than irrigated paddy systems (2.85 kg CO₂e kg⁻¹ grain), underscoring the mitigation co-benefits of dietary diversification towards millets.

Policy analysis reveals that India's declaration of 2023 as the International Year of Millets, its National Millet Mission, and its integration of millets into public distribution and mid-day meal programmes represent a transformative shift in agricultural policy orientation. However, critical structural barriers — including entrenched Minimum Support Price distortions, fragmented seed systems, and underdeveloped value chains — continue to constrain large-scale adoption. The review concludes with a spatially differentiated policy framework, a structured research agenda prioritising genomics-assisted breeding and AI-driven agronomy, and evidence-based recommendations for realising the full climate resilience potential of millet agriculture at scale.