In a recent study published in Geoderma, Xu et al., explored the use of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More interlayers to improve saline wastelands. Biochar, a carbon-rich material, has been recognized for its agricultural benefits, but its application as an interlayer in saline soils remains understudied. The research focused on how biochar interlayers affect water and salt movement in soils cultivated with Suaeda salsa, a salt-tolerant plant, over both growth and non-growth periods.  

The study revealed that biochar interlayers can significantly reduce soil salinity. During the non-growth period, these interlayers decreased groundwater evaporation and surface salt accumulation, leading to a 13.14% to 49.62% reduction in soil salinity in the top 40 cm of soil. In the growth period, biochar enhanced water retention and further decreased salinity, with water content increasing by 0.14% to 18.92% and salt content decreasing by 24.51% to 36.64% in the top 40 cm.  

Moreover, the roots of S. salsa effectively used water and salt from the biochar interlayer, increasing salt content in the plant and improving yield by 22.12% to 65.92%. The salt absorption efficiency of the plant also increased significantly, by 30.62% to 85.03%. However, the authors cautioned that excessive biochar use could hinder surface soil desalination and potentially cause secondary salinization. The study suggests that a moderate application rate of 45 Mg/ha of biochar is optimal for balancing water retention and salt suppression in saline wastelands.  

This research offers valuable insights for the sustainable use of saline wasteland, particularly in arid regions where salinity poses a significant challenge to agriculture.  

SOURCE: Xu, Q., Xu, Y., Xia, H., Han, H., Li, M., Gong, P., Wang, C., Li, Y., Li, P., & Liu, H. (2025). Mitigation of soil salinity by biochar and halophytes. Geoderma, 454, 117191.