Overview of biochar role in remediating soil salinity stress in crops

Summary

This narrative review examines biochar's role in remediating soil salinity stress, a growing challenge in semi-arid and arid regions exacerbated by climate change and seawater intrusion. The analysis emphasises biochar's inherent chemical properties—particularly high cation and anion exchange capacities—which enable salt ion sorption and improve soil conditions for crop growth. The authors conclude that biochar application reduces soil electrical conductivity, enhances water and nutrient availability, and promotes crop performance under saline irrigation, while suggesting future research should explore synergistic effects with complementary soil management practices and nano-biochar development.

Regional applicability

The findings are most directly applicable to semi-arid and arid regions where soil salinity is a primary constraint; however, biochar remediation strategies may have limited relevance to United Kingdom agriculture given the cooler, wetter climate and lower prevalence of salt-affected soils. Transferability to UK contexts would depend on localised salinity problems (e.g., coastal farmland, legacy industrial contamination) and would require evaluation of biochar sourcing and cost-effectiveness relative to conventional drainage or soil amendment approaches.

Key measures

Electrical conductivity (EC, dS/m), cation exchange capacity (CEC), anion exchange capacity (AEC), soil moisture retention, plant K+ availability, soil nutrient content, crop yield and performance under salt stress

Outcomes reported

The review synthesised evidence on biochar's mechanisms in remediating soil salinity, particularly through cation and anion exchange capacities. Key reported effects included reduced soil electrical conductivity, improved plant water uptake, increased nutrient availability, and enhanced crop performance under saline conditions.

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