Qu et al., investigated the effects of biochar-based organic fertilizers on the movement and accumulation of heavy metals in soil and plants. The study, published in Fermentation, focused on the potential 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 to reduce the risk of heavy metal pollution associated with the use of anaerobically digested digestate as organic fertilizer.

Digestate, a byproduct of anaerobic digestion, is rich in nutrients but may also contain heavy metals. These heavy metals can accumulate in the soil and be taken up by plants, posing potential risks to human health through the food chain.  

The researchers found that adding biochar to the digestate helped reduce the mobility of heavy metals in the soil. The biochar promoted the transformation of heavy metals from a weakly acid-extractable state to a more stable residue state, reducing their availability for plant uptake.  

The study also found that the accumulation of heavy metals in cabbage plants was mainly in the below-ground parts (roots). The addition of biochar-based organic fertilizer effectively reduced the mobility and uptake of heavy metals, making it a safer option for recycling biowaste and improving soil health.  

Qu, J.; Wang, F.; Qi, X.; Che, S.; Che, Y.; Li, J.; Wei, Z. Effect of Biochar-Based Organic Fertilizers on the Transport and Accumulation of Heavy Metals in Soil and Plants. Fermentation 2025, 11, 48. https://doi.org/10.3390/fermentation11020048