Copper-contaminated soils from mining activities pose a major challenge for plant growth and soil remediation. A recent study examined the combined 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 and microbial inoculants to address these issues, focusing on sunflower cultivation as a phytoremediationThis is a technique that uses plants to clean up contaminated soil or water. Biochar can enhance phytoremediation by improving soil conditions and promoting plant growth, allowing plants to absorb and break down pollutants more effectively.   More strategy.

The study revealed that while biochar amendments (at 2.5% and 5%) improved copper availability in the soil, this also led to increased copper accumulation in sunflower roots, reducing both shoot and root 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. Biochar’s effects highlight its potential risks, as copper-induced toxicity negatively affected plant development.

Conversely, microbial inoculants, particularly a combination of Pseudomonas reactans EDP28 and Rhizophagus irregularis, demonstrated significant benefits. These inoculants enhanced sunflower growth, improving chlorophyll content, nutrient use efficiencyNutrient use efficiency refers to how effectively plants can take up and utilize nutrients from the soil. Biochar can improve nutrient use efficiency by enhancing nutrient availability and retention in the soil.   More, and overall biomass production. Even in biochar-amended soils, microbial treatments mitigated some adverse effects, though growth reductions remained.

The findings underscore the importance of careful biochar application to balance copper bioavailability and minimize toxicity. At the same time, microbial inoculants show promise for improving plant resilience and boosting phytoremediation efficiency. The synergistic use of these approaches requires further optimization to ensure sustainable soil management in contaminated mining regions.

Future research should refine application rates of biochar and inoculants while assessing their cost-effectiveness and potential for large-scale implementation. This could help transform degraded soils into productive ecosystems, aligning with sustainable land management goals.

Godinho, et al (2025) Microbial inoculants alleviate the adverse effects of Cu-contaminated soils amended with biochar on sunflower growth. Soil Advances. https://doi.org/10.1016/j.soilad.2024.100029