Biochar application in agroecosystems: a review of potential benefits and limitations

Biochar (BC), a carbon-rich material produced by pyrolysis, has recently demonstrated promising results for the sustainable management of agroecosystems. It can enhance plant growth and improve soil health. The application of BC can significantly shrink soil's bulk density while improving the porosity, water-holding capacity and aggregation, organic matter, cation exchange capacity, and pH. Additionally, BC addition was a promising method to manage environmental stresses (heavy metals (HMs), drought, salinity, and flooding). On the other hand, several adverse effects of BC application were also observed, such as decreased water-holding capacity, increased soil erosion, and salinization, altered pH, imbalanced nutrients, influenced soil biota, and the addition of HMs. Overall, it can be concluded that although BC has been introduced as an potent approach for improving soil characteristics, further studies should be conducted, particularly on prolonged and large scale, to comprehensively assess the adverse effects of BC. Considering these pros and cons of BC applications, especially in soil systems and for sustainable agriculture, the present review aimed to explore insights into the contribution of BC to improving soil physicochemical properties, mitigating environmental stresses, and promoting plant growth and development. Moreover, drawbacks associated with this approach towards enhancing soil health have also been elucidated.