In a study published in the journal Scientific Reports, researchers Ghulam Murtaza and his colleagues investigated how 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 made from banana peels can help soybean plants withstand salt stress. The experiment, which took place in a greenhouse in Bahawalpur, Pakistan, involved exposing soybean plants to different levels of salinity and biochar. Their findings suggest that biochar can protect soybean plants from the damaging effects of high salt concentrations by reducing oxidative stress and enhancing overall plant health.

Salt stress is a major problem for crop production globally, as it inhibits plant growth by disrupting osmotic balance and ion homeostasis. When exposed to salt, plants produce excessive reactive oxygen species (ROS), which can damage proteins, lipids, and nucleic acids. To combat this, plants activate antioxidant defense systems, producing enzymes like superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) to mitigate the damage. Additionally, they accumulate osmolytes such as soluble proteins, sugars, and proline to maintain cellular water content and turgor pressure.

The study found that without biochar, salt stress reduced soybean root and shoot dry weight by 17% and 21%, respectively. It also significantly increased the levels of damaging compounds like hydrogen peroxide (H2​O2​), oxygen radicals (O2​⋅−), and malondialdehyde (MDA) by up to 2.3-fold, 1.4-fold, and 2.2-fold, respectively. The plants’ defense systems were clearly activated, with antioxidant enzyme activities rising substantially. For example, SOD activity increased by 3.1-fold, PPO by 1.8-fold, POD by 3.1-fold, APX by 2.8-fold, and CAT by 4.4-fold. Osmolytes like soluble protein and proline also became more concentrated to help the plant cope.

However, when biochar was added to the soil, the negative effects of salinity were significantly reduced. Biochar, especially at a concentration of 25%, enhanced the dry weight of both roots and shoots by 47% and 53%, respectively, when compared to plants grown without biochar. The addition of biochar also led to a notable decrease in harmful substances. It reduced hydrogen peroxide (H2​O2​) by 27%, oxygen radicals (O2​⋅−) by 19%, and MDA by 22%. This reduction in oxidative damage was associated with a decrease in the activity of antioxidant enzymes and the accumulation of osmolytes, suggesting that the biochar helped the plants avoid the initial stress response.

The researchers conclude that biochar’s beneficial effects are likely due to its ability to improve soil properties, increase nutrient availability, and reduce soil salinity. By temporarily binding to sodium ions and improving soil moisture, biochar lessens the stress on the plant, allowing it to grow and thrive even in saline conditions. This study demonstrates that biochar, specifically from banana peels, can be a low-cost, effective, and environmentally friendly way to combat soil degradation and enhance crop production in salt-affected areas.

Source: Murtaza, G., Rizwan, M., Usman, M., Ahmed, Z., Iqbal, J., Ahmad, S., Alwahibi, M.S., Rizwana, H., Iqbal, R., Deng, G., & Lackner, M. (2025). Physiological and biochemical alterations in soybean by banana peel biochar under different degrees of salt stress. Scientific Reports, 15(30532).