Enhanced rock weathering for improved smallholder farmer welfare: An at-scale case study for rice agriculture in India

Smallholder farmers produce approximately one-third of the world’s food supply, but face persistent challenges from soil degradation, limited access to affordable inputs and growing climate variability. Utilizing enhanced rock weathering (ERW) offers a pathway to address these constraints while generating durable carbon dioxide removal (CDR). Commercial-scale deployments by Mati Carbon during the 2024 summer monsoon rice growing season in Chhattisgarh, India applied basalt on over 2,000 acres ( 810 ha) farmed by more than 600 smallholders. Key agronomic findings from paired field measurements indicate a median yield increase of 22.9%, corresponding to estimated revenue gains of $303 per farmer, or approximately 20% of baseline household income. Inference via a simplified mass-balance model applied to soil geochemical data constrains the first-year weathering extent at τ = 0.27 (68% CI: 0.14–0.39), yielding an initial CDR potential of 1.6 (0.8–2.3) tons CO2 per acre (4.0 (2.1–5.7) t CO2/ha). Together, these results demonstrate that ERW can simultaneously deliver measurable livelihood benefits and climate mitigation under real-world smallholder conditions. Importantly, CDR generates monetizable carbon removal outcomes that are economically separate from on farm productivity gains, enabling climate finance to underwrite the costs of soil restoration without requiring farmer co investment. Combined measurement of CDR potential and yield response provides the empirical foundation for scaling ERW in smallholder systems. Establishing these outcomes demonstrates a replicable pathway for climate-financed agricultural development.