A multifunctional eco-friendly fertilizer used keratin-based superabsorbent as coatings for slow-release urea and remediation of contaminated soil

Development of an eco-friendly slow-release fertilizer based on waste has great significance in modern agriculture on account of expensive, incomplete degradation and restrictions of sourcing materials of traditional slow-release fertilizers. In this study, the extracted keratin from waste bovine hair reacted with AA (Acrylic acid), MBA (N,N-methylenebis acrylamide) to form keratin-based superabsorbent (KSA). Then KSA was used as outer coating material, ethyl cellulose as the inner layer for the fertilizer core, which used lignin powder to wrap urea particles. This would be a multifunctional eco-friendly fertilizer (MEF) for slow-release urea and remediation soil. The performance of MEF was studied. The results demonstrated that the KSA could improve water-retention of soil. It could also improve the utilization rate of fertilizers by slowing down release of nutrients. The cumulative urea release rate was 81.32 % when MEF was soaked in deionized water for 180 min. About 90.80 % of Cr (?) in the soil could be inhibited by the leaching experiment, which indicated that MEF has a remediation effect on soil polluted by heavy metals. The growth experiments showed that the MEF had a positive role in wheat growth. Therefore MEF has broad industrial and green agricultural applications.

Automated summary

The study developed an eco-friendly slow-release fertilizer based on waste, which can improve soil water retention, slow down nutrient release, and remediate heavy metal contaminated soil, while also exerting a positive effect on wheat growth.