A Review of Biochar Production and Application in the Agroforestry Sector

Abstract

Biochar is produced from the thermo-chemical treatment of biomass. Its quality and yield differ remarkably depending on the thermo-chemical technology and operational parameters deployed, which in turn influence its functionality in the agroforestry sector. In this review, different thermo-chemical technologies for biochar production such as pyrolysis (fast and slow), gasification, and torrefaction were analyzed and compared. It was discovered that biochar yield decreases with increase in heating rate and increase in oxygen amount. The benefits of applying biochar in agroforestry systems were examined. Enhancements in soil health, plant development, carbon sequestration, and mitigation of greenhouse gas emissions were observed in several instances, however, undesirable outcomes were equally discovered. This is an indication that the benefits from biochar application depend particularly on parameters such as the source of biochar, rate of biochar application, types of soil, climatic conditions, and species of plant. Limitations of available studies and recommendations for future investigations on biochar production and applications were also examined. Specifically, the influence of production technologies on biochar properties and its functionality in the agroforestry sector need to be further comprehended.