Effect and viability of Guadua angustifolia Kunth biochar on soil conditions and the development of Zea mays L.

Global demand for food has led to an increase in the use of fertilisers, which have negative environmental impacts on soil, water and air. In this context, biochar is proposed as a sustainable alternative to improve soil health and reduce dependence on agricultural inputs. This study evaluated the environmental, productive, and economic viability of biochar made from Guadua angustifolia Kunth in Zea mays L. plants in Pitalito, Huila (Colombia). Five treatments were applied: T1 (conventional synthetic fertilisation), T2 and T3 (synthetic fertilisation with 80 and 160 g of biochar per plant), T4 and T5 (80 and 160 g of biochar per plant), using a completely randomised design and three replicates. The results showed that T2 (equivalent to 5 t/ha of biochar) presented a ~10% increase in above-ground biomass compared to T1, improved soil parameters such as pH, cation exchange capacity and reduction of exchangeable aluminium (~63%). Biochar also showed a carbon capture potential of 2 135–2 155 kg CO₂eq/t, with the possibility of generating removal certificates (CORCs). The production cost per tonne was estimated at USD 303, and total application cost per hectare was estimated at USD 1 816 at a dose of 5 t/ha.