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

Mati Carbon uses basalt-based Enhanced Rock Weathering (ERW) to supplement the income of smallholder farmers while promoting climate resilience. In facilitating future participation in carbon markets for smallholder farmers, Mati provides opportunities for agronomic benefits for individual partnered farmers while paving the way towards economically viable, gigaton scale CDR in regions throughout the Global South.    

Currently, Mati operates at scale (100,000 tons of basalt deployable per annum) at centralized locations within Chhattisgarh and Madhya Pradesh. These states of India have a large number of smallholder rice paddy farmers. The regional Indian farming practice involves flooding and vigorous wet tilling of rice paddies, creating homogenized soil ideal for basalt integration. Rice paddies have two primary growing seasons: Rabi (winter, dry season) and Kharif (summer, monsoonal season). 

For each deployment, Mati monitors the crop yield for all enrolled farmers. Many of our partnered farmers do not deploy basalt on all of their fields, which allows for comparison of the crop yield in deployed versus control plots.  Along with biomass measurements and crop density estimations, we conduct detailed farmer surveys to monitor the agricultural practices of each enrolled farmer and the performance of their crops after ERW deployment. Additionally, rice yield estimates from farmers are reported to the Indian government.

In 2024 Mati deployed 22,402 metric tons of basalt with 344 farmers at the Madhya Pradesh site and 49,880 metric tons with 711 farmers in Chhattisgarh.  In 2023 Mati deployed 7,898 metric tons of basalt with 293 farmers in Chhattisgarh.  Here, we compare mean yield changes for rice production across the Kharif (summer monsoonal season).  Combining internally collected survey data and rice yield figures reported to the government, we conduct a meta-analysis of the rice yield data from our partnered farmers. We report significant mean production increases for rice yield.  Throughout the Chhattisgarh Kharif in 2023 the mean increase for rice productivity (kg/ac) was 14.39% (n=162).  In the 2024 Kharif, the mean increase in rice yield at Chhattisgarh was 27.79% (n=44).  In the 2024 Kharif season at Madhya Pradesh, the mean measured yield increase was 18.79% (n=18).  We estimate that partnered smallholder farmers in India benefitted by an integrated income increase of over one million dollars through our 2024 ERW deployments.  This income increase is due to both incremental increases in productivity and reduced input costs.