New Study Finds 30 Percent Corn Stalk Use Cuts Soil Microplastics by Over 50 Percent

A groundbreaking study by Yangzhou University has introduced an eco-friendly solution that could revolutionize fertilizer use while tackling one of agriculture’s most pressing issues—microplastic pollution from traditional polymer-coated fertilizers. By replacing 30% of castor oil with liquefied corn stalks (LCS) in bio-based polyurethane (PU) coatings, researchers have significantly improved biodegradability without sacrificing the slow-release function of urea fertilizers.

The innovative PU coating combines LCS-derived polyols with glycerol and acrylamide as crosslinkers, alongside castor oil and isocyanates. Using infrared spectroscopy, scanning electron microscopy, and thermal analysis, the study confirmed the hybrid material’s superior structural integrity and enhanced hydrophobicity, both critical for nutrient release control.

While conventional castor oil PU showed the longest nitrogen release duration at 14.58 days, the LCS-enhanced versions achieved nearly the same release window—up to 14.41 days—with improved degradation rates. After 210 days, the LCS-based coatings degraded by up to 7.91%, compared to just 5.86% for their petrochemical-rich counterparts.

More importantly, the presence of microplastics in treated soil dropped dramatically. Soil with traditional PU coatings contained up to 16 particles per 1.5g, while LCS variants reduced this to just 6–7 particles, cutting plastic contamination by more than half. The study also demonstrated that surface morphology improved, reducing cracks and optimizing the fertilizer release process.

This research offers a dual benefit: turning agricultural waste into valuable materials and reducing environmental harm. It sets the stage for broader adoption of biodegradable, plant-based coatings in commercial fertilizer production. With environmental regulations tightening and sustainability gaining urgency, these findings offer both an environmental and economic breakthrough.