Driving Sustainable Circular Economy in Agriculture Through Napier Grass Cultivation: The Case of Rural West Bengal, India

This study evaluates the scalability and sustainability impacts of integrating Napier grass cultivation with biofertilizer production and dairy systems in rural West Bengal. Field-level evidence indicates that biofertilizer application and irrigation optimization significantly enhance soil organic carbon (SOC), improving nutrient availability and enabling Napier yields of up to 500 tons/acre on fallow land. A technoeconomic model shows strong economies of scale, with production costs decreasing by 40% when area under cultivation is simulated from 1 acre to 100 acres. Statewide scaling scenarios demonstrate significant development potential. Under 10% adoption of fallow land by 2040, approximately 75 million tons of biomass can be grown annually, benefiting 3.75 million households, doubling under a 20% adoption scenario by 2050. The system enables a 2.5–4× increase in household income while delivering substantial climate co-benefits. Avoided emissions from manure management are estimated at ~40 Mt CO2 annually by 2040, increasing to ~80 Mt CO2 by 2050, alongside additional gains from soil carbon sequestration and reduced high-emission urea-use. Overall, the proposed circular model offers a scalable pathway for achieving multiple Sustainable Development Goals through integrated agricultural transformation.