Is Global Crop Yield Enhancement and Emissions Mitigation by Biochar Application Feasible from a Biochar Resource Availability Perspective?

Evaluating biochar’s potential for reducing greenhouse gas (GHG) emissions and increasing crop yields globally is essential to addressing climate change challenges. Analysis of 2140 data pairs from controlled field trials and global livestock manure and crop straw raster layers across diverse soils, climates, and management practices revealed an average global biochar production potential of 1.89 t/ha. Biochar application (BA) increased crop yields by 38% and reduced GHG emissions by an average of 23%. Specifically, biochar management with rotary tilling and deep application (20–50 cm) shows promise, reducing GHG emissions by 27% and boosting yields by 33%. In terms of biochar production technologies, the application of woody biochar and manure biochar to the deeper soil layer (20–50 cm) with large particle size (> 3 mm) and low pyrolysis temperature (200–400°C) can significantly improve crop yield by 42.6% ( p  < 0.05). High pyrolysis temperature (800–1000°C) and small particle size (< 3 mm) of surface (0–20 cm) applied by straw biochar significantly reduces GHG emissions by 20.5% ( p  < 0.05). However, in 32.52% of global areas there are limitations of biochar feedstock resources for practical applications, which could make its widespread adoption challenging. Sustainable biochar use can support agricultural carbon neutrality, but realizing its full benefit will require region-specific policies and management based on local biomass availability.