Yan, X., Wang, Z., Zhao, M. et al. Hydrothermal 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 enhances the photosynthetic efficiency and yield of alfalfa by optimizing soil chemical properties and stimulating the activity of microbial communities. Sci Rep14, 31420 (2024). https://doi.org/10.1038/s41598-024-83098-9

Hydrothermal biochar is gaining attention as a 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 for enhancing crop growth. A recent study explored its effects on alfalfa, a key forage crop, focusing on soil health, photosynthetic performance, and microbial activity.

The study evaluated various biochar application rates (0–50 tons/ha) and identified 10–20 tons/ha as optimal for improving alfalfa growth. Moderate application boosted plant 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, photosynthetic efficiency, and soil fertility. Notably, alfalfa leaf biomass increased by up to 21%, while chlorophyll content and photosystem II efficiency also improved. This was attributed to enhanced soil nutrient availability, particularly phosphorus, and enriched soil organic matter.

Biochar’s benefits extended to soil chemical properties and microbial diversity. It increased total nitrogen, phosphorus, and organic carbon in the soil while reducing 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. These changes created a more favorable environment for bacterial communities, though effects on fungal communities were minimal. Soil enzyme activities, critical for nutrient cycling, were also elevated at moderate biochar levels.

However, excessive biochar (≥30 tons/ha) inhibited plant growth, reduced photosynthetic efficiency, and altered microbial communities, likely due to nutrient imbalances and reduced enzyme activities. These findings highlight the need for balanced biochar application to avoid adverse effects.

This research underscores hydrothermal biochar’s potential for sustainable alfalfa cultivation. Future studies should investigate its long-term impacts across diverse soil types to refine application strategies and maximize benefits.