A recent study by Xin Tang and colleagues, published in Industrial Crops & Products, introduces an innovative approach to controlled-release fertilizers (CRFs) by combining 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 bio-based polyurethane. This method not only recycles agricultural waste but also addresses critical issues of fertilizer inefficiency and environmental impact.

The team developed bio-based double-coated controlled-release fertilizers (BDCRFs) using biochar from materials like tobacco stems and a polyurethane coating made from liquefied tobacco stems and castor oil. These fertilizers demonstrate improved nutrient release control compared to conventional options, with the release rate lasting up to 124 days depending on the coating thickness. The researchers found that biochar’s hydrophobic and lipophilic properties significantly enhance the coating’s effectiveness.

Field trials on tobacco crops showed promising results: BDCRFs with a 5% coating performed best, matching nutrient release to the plant’s growth cycle. This reduced labor costs by eliminating the need for repeated applications, a common drawback with traditional fertilizers. Additionally, the economic analysis revealed production costs for these fertilizers were lower than many commercial CRFs.

The study underscores the potential of BDCRFs in promoting circular agriculture by turning waste into value-added products. While the current focus is on tobacco crops, further research could explore broader applications across other farming systems. The findings offer a sustainable pathway to enhance agricultural productivity while minimizing environmental harm.

This innovative approach signals a step forward in aligning agricultural practices with sustainability goals.

SOURCE: Tang, et al (2025) Agricultural sustainability: Biochar and bio-based polyurethane coupling coating to prepare novel controlled-release fertilizers. Industrial Crops and Products. https://doi.org/10.1016/j.indcrop.2024.120296