Opportunities and challenges of applying biochar to boost agricultural output and repair salt-damaged soils

Abstract

Soil salinization is recognized as a serious form of soil degradation, affecting crop production and compromising food security. It is crucial to remediate the negative impacts of soil salinization to improve the associated soil functions. Biochar amendments are used to reclaim the salt-affected lands. Therefore, the main objective of the present paper was to review and discuss the recent studies investigating a role of biochar in improving soil properties and plant growth in salt-affected soils. Recently, biochar (solid carbonaceous residue, produced under oxygen-free or oxygen-limited conditions at temperatures ranging from 300 to 1000 C) has attracted considerable attention as a soil amendment. An emerging pool of knowledge shows that biochar addition is effective in improving physical, chemical and biological properties of salt-affected soils. Biochar amendments improve not soil properties but also support plant growth and ameliorate soil problems. However, some studies have also found an increase in soil salinity with biochar application at high rates. Further, the high cost associated with production of biochar and high application rates remains a significant challenge to its widespread use in areas affected by salinity. Therefore, the underlying mechanisms of such beneficial effects provided by biochar amendment of soils are highly complex. Therefore, more in-depth studies are needed to understand biochar interactions with soil organisms under extreme environments, which would help achieve maximum benefits of biochar under saline soil conditions.