Saline-alkali soil degradation is a critical and growing threat to global food security. More than 1 billion hectares of land worldwide are affected by high salt and pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More levels, a problem worsened by climate change and unsustainable irrigation. For decades, the primary solutions involved costly, energy-intensive, and environmentally disruptive methods like chemical leachingLeaching is the process where nutrients are dissolved and carried away from the soil by water. This can lead to nutrient depletion and environmental pollution. Biochar can help reduce leaching by improving nutrient retention in the soil.   More and physical drainage. A new comprehensive review by Hu Liu, Jian Wang, and their colleagues , published in EEMIT 2025 , synthesizes the latest advances in biological remediation, offering a far more sustainable and scalable alternative. The research highlights a powerful three-pronged approach: harnessing plant-microbe partnerships, using CRISPR gene editing to create super-resilient crops, and applying engineered biochar to heal the soil itself.

The first strategy leverages the power of the soil microbiome, recognizing that plants do not grow in isolation. The review points to significant progress in using “plant growth-promoting rhizobacteria” (PGPR) to help crops thrive in salty conditions. For example, a 2023 study found that PGPR like Bacillus subtilis can secrete compounds that promote root development, increasing a plant’s biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More by 35%. Even more impressively, inoculating sweet clover with the microbe Sinorhizobium meliloti enhanced nitrogen fixation efficiency by 30% and boosted total soil nitrogen by 15%. Other microbes, such as Novosphingobium sp., work by secreting organic acids, which lower the rhizosphere’s pH and unlock crucial nutrients like phosphorus for the plant.

While microbes help from the outside, CRISPR-Cas9 gene editing is toughening up plants from the inside. This technology allows for precise genetic modifications to rapidly breed crops with elite salt tolerance. The review highlights a breakthrough 2023 study where researchers knocked out a single gene, AT1, in sorghum and rice. The result was a stunning 20% to 27.8% yield increase, even when grown in highly alkaline soil with a pH of 9.1. This edit helps the plant alleviate oxidative damage caused by the stress. In another example, editing the GSSOS1 gene in alfalfa increased its survival rate in saline soils by a remarkable 50%.

The third pillar of this integrated approach is engineered biochar, a charcoal-like soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More that offers a sustainable, carbon-negative solution. The review notes that specialized biochars can have a massive impact; one Ca/Mg-modified biochar was shown to increase soil organic matter content by an incredible 320%. Field studies confirm these strategies work in the real world. Planting hybrid mulberry, for instance, reduced soil sodium by 37% and increased organic matter by 25% in just two years, partly by releasing compounds that attract beneficial salt-tolerant microbes. Similarly, a monoculture of the halophyte (salt-loving plant) Halogeton glomeratus also achieved a 37% reduction in soil sodium.

Ultimately, the authors argue that the future of remediation lies not in any single solution, but in an integrated framework that combines these innovations. By pairing CRISPR-edited crops with tailored microbial communities and amending the soil with engineered biochar, it is possible to restore degraded lands, reduce chemical inputs, and sequester carbon. This multi-scale approach provides a practical roadmap for achieving sustainable agriculture and food security on a planet under increasing environmental stress.

Source: Liu, H., Wang, Q., Wang, J., Li, H., Zhou, H., Xi, W., & Gao, L. (2025). Integrated Strategies for Saline-Alkali Soil Remediation: Advances in Plant-Microbe Interactions, CRISPR-Based Breeding, and Sustainable Biochar Applications. EEMIT 2025.