The Discover Sustainability journal recently published a review by Abdulrahman Maina Zubairu, Jana Marjanović, Mustapha Abdulkadir, and colleagues examining conceptual frameworks for restoring soil fertility in Borno State, Nigeria. The researchers explored how utilizing locally available agricultural wastes for biochar production can address the severe climatic challenges of this arid region, such as frequent droughts and poor soil structure. Their synthesis suggests that transitioning from traditional residue burning to controlled pyrolysis represents an environmentally responsible way to transform waste into valuable soil amendments. By focusing on locally adapted technologies like modified drum kilns, the study provides a roadmap for sustainable agriculture that aligns with post-conflict restoration goals in northern Nigeria.

The findings indicate that several feedstocks available in Borno State are highly suitable for biochar production. Cereal residues such as maize stems, sorghum husks, and millet stalks are abundant and easy to process, yielding biochar with high porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More that is ideal for improving water retention in sandy soils. Leguminous wastes like cowpea husks provide higher nitrogen content, which is critical for addressing the severe nutrient deficiencies common in the region’s soil. Furthermore, invasive species like Prosopis juliflora and tree litter from Neem trees can be converted into highly stable biochar with long-term carbon sequestration potential. These materials, which are often burned or left as a nuisance, can instead be used to build a lasting soil organic matter base.

Applying biochar to Borno’s arid soils offers multiple physical and chemical benefits over direct residue use. Unlike raw manure or crop residues that decay rapidly in high temperatures, biochar provides a stable, porous matrix that retains nutrients and prevents them from leachingLeaching is the process where nutrients are dissolved and carried away from the soil by water. This can lead to nutrient depletion and environmental pollution. Biochar can help reduce leaching by improving nutrient retention in the soil.   More during unpredictable rainfall. It significantly enhances soil physical properties by reducing bulk density and increasing porosity, which facilitates better root growth and water infiltration. Studies from other arid regions demonstrate that biochar can increase crop yields by 10% to 30%, specifically aiding staples like wheat and maize. Additionally, biochar can help mitigate soil salinity—a common issue in Borno—by reducing electrical conductivity and improving conditions for plant development.

Economic analysis shows that adopting biochar technology is a viable path for smallholder farmers to increase their livelihoods. Using simple, low-cost technologies such as a 200-liter drum kiln requires a modest initial investment of approximately 26,249 NGN. Because most smallholder systems in the region rely on family labor, there is often no additional operational labor cost. When the average yield improvement of 17.56% is applied to baseline farm profits, a household could see a net additional earning of over 517,000 NGN annually. This value-added approach to waste management far exceeds the minimal income currently derived from informal waste reuse.

However, successful implementation requires a coordinated strategy to overcome socio-cultural and technical hurdles. Many local farmers are currently unaware of biochar’s potential or may view it as an exotic, risky technology compared to ancestral farming methods. Effective extension services and participatory strategies involving community leaders are essential to foster adoption. The study recommends establishing a localized system-based approach, including hands-on farmer training in local languages like Kanuri and Hausa. By integrating biochar into established regional agricultural goals and providing technical aid for cheap, local kiln distribution, Borno State can achieve sustainable soil restoration and enhanced food security.

Source: Zubairu, A. M., Marjanović, J., Abdulkadir, M., Eldawwy, N., Takács, A., Ocansey, C. M., & Gulyás, M. (2025). Conceptual framework for restoring soil fertility in arid Borno state, Nigeria with biochar from agricultural wastes. Discover Sustainability.