Exploring the biochar contribution in sustainable agriculture through techno-economic assessment and water impact simulations

In an age shaped by climate change, which is disrupting natural ecosystems’ balances and impacting both human and animal health, society must actively attenuate these changes. From this perspective, innovative and sustainable resources are needed to mitigate water scarcity, ensure food security, and reduce air pollution. Biochar could play a key role in this effort due to its ability to provide benefits for agriculture by reducing water demand, increasing yields, reducing fertilize use and promoting resistance to stress and diseases. It also offers environmental benefits by capturing and storing carbon in the soil for extremely long periods, valorizing bio-waste that is currently lost, and generating economic value through the generation of carbon offsets. Biochar production and its incorporation into soil address twin challenges: supporting farmers and sustaining the environment by transforming waste into a value-added product. This thesis presents a techno-economic evaluation of biochar production, including its physical and chemical characteristics, certification processes, and application methods. Focus is given to a detailed analysis of existing carbon credit systems, the biochar market, and its key stakeholders, which have the potential to generate significant revenue streams. Moreover, this work aims to analyze how applied biochar interacts with agricultural soils, examining all the related physical, chemical and biological modifications and effects. The final section investigates the relationship between biochar-induced soil changes and crop performance, simulating multiple scenarios soils, environments, and crops, using the FAO AquaCrop software, while maintaining a consistently critical perspective on the environmental benefits such as reducing water demand and improving agricultural efficiency. This work is grounded in a thorough literature review, critical analysis and data manipulation, complemented by interviews with leading experts in the field, to gain expert know-how. This work outlines the complexity of the regulatory framework that farmers face when adopting this new resource, which increases skepticism and reduces adoption rates, which in turn promotes economic barriers: this is confirmed by data, showing that 58% of users do not earn income from carbon offsetting. Nevertheless, the sector is continuously growing, with an expected CAGR of 55% and a projected production capacity of 220 t/y for 2025, with Northern European countries leading the EU market. AquaCrop simulations were run focusing on hydraulic changes extracted from Edeh et al. (2020) "A meta-analysis on biochar’s effects on soil water properties". Simulations highlight that in sandy soil results are more relevant, leading up to + 12% of biomass produced and more than 10% in irrigation efficiency, while in clay soil results are quite negligible. However, biochar is considered a great crop stress buffer and enhanced soil water retention. Moreover, the ability to perform multiple simulation runs across diverse environmental conditions, irrigation schedules, and crop types makes it possible to directly investigate the correlation between biochar application and crop biomass production. Scaling biochar technologies will require harmonized certification frameworks that recognize both agronomic and carbon-sequestration services. Embedding biochar within circular bioeconomy strategies offers a scalable pathway to resilient agriculture and tangible climate action storing 3 kg of CO2eq for 1 kg of biochar buried.