Biochar as Sustainable Solution for Reducing Chemical Inputs and Enhancing Soil Quality Under Agroecological System

Biochar, a carbon‐rich material obtained from the pyrolysis of organic residues, has been used as an innovative, low‐cost, and eco‐friendly approach in agroecological systems in order to increase soil fertility and reduce the use of chemical inputs. In this study, an experiment field was conducted during the 2023–2024 agricultural season to investigate the partial substitution of biochar and chemical fertilizer (DAP) on soil quality and durum wheat yield in the northwest of Tunisia. The experiment included five treatments: A: control, B: soil amended with biochar at a rate of 20 t/ha, C: soil amended with biochar combined with 100% chemical fertilizers (150 kg/ha of DAP), D: soil amended with biochar combined with 50% DAP, and E: soil amended with 100% DAP. Soil physicochemical properties were monitored at different growth stages, along with wheat productivity at maturity. The results showed that biochar application significantly enhanced soil enzymatic activity and improved nutrient availability and uptake. Furthermore, treatments combining biochar with DAP (C and D) increased grain yield relative to straw yield and reduced the mitadinage rate, thereby improving grain quality. Among the five treatments, C proved to be the most profitable, while D represented a more sustainable option by reducing fertilizer input while maintaining high productivity.