Research and Application Progress of Biochar in Amelioration of Saline-Alkali Soil

Saline-alkali soils pose a significant global challenge to agricultural productivity, necessitating sustainable remediation strategies to unlock their cultivation potential. Biochar has emerged as a promising soil amendment, exhibiting multifunctional capabilities in pH regulation, contaminant immobilization, carbon sequestration, and nutrient retention. However, the heterogeneous nature of biochar compositions results in inconsistent remediation outcomes, while the mechanistic understanding of its interactions with saline-alkali soils remains incomplete. This chapter provides a comprehensive analysis of the effects of biochar on the physicochemical properties, nutrient availability, and biological characteristics of saline-alkali soils. It summarizes the improvement effects of both biochar and modified biochar on saline-alkali soils, evaluates their impacts on quality and efficiency, and elucidates the potential mechanisms underlying biochar’s role in saline-alkali soil remediation. Furthermore, this chapter outlines future research directions to provide a reference for developing green, efficient, and precise biochar-based technologies tailored to saline-alkali soil remediation, bridging the gap between fundamental research and large-scale agricultural applications.