Rapid scale-up, real returns: Potato zero tillage and mulching increases profitability by 16% in Bihar, India

This policy brief presents evidence from a three-year randomized controlled trial and large-scale end-of-project monitoring on potato zero tillage and mulching (PZTM) in Bihar, India. Results show that PZTM increased gross margins by 16%, driven primarily by a 31% reduction in production costs and complemented by yield gains of 5.4%. Adoption expanded rapidly to over 7,700 farmers by 2025, supported by video-based extension delivered through women-led village resource persons. The study demonstrates that regenerative practices can simultaneously improve profitability, climate resilience, and environmental outcomes in smallholder rice–potato systems.