Use of natural and biobased materials for controlled-release of urea in water: Environmental applications

Authors: Bilbao-Sainz, Cristina; Imam, Syed; Franquivillanueva, Diana; Wood, Delilah - De; Chiou, Bor-Sen; Orts, William

Submitted to: Basic Research Journal of Soil and Environmental Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2013
Publication Date: 7/30/2013
Citation: Bilbao-Sainz, C., Imam, S.H., Franquivillanueva, D.M., Wood, D.F., Chiou, B., Orts, W.J. 2013. Use of natural and biobased materials for controlled-release of urea in water: Environmental applications. Basic Research Journal of Soil and Environmental Science. 1(3):23-30.

Interpretive Summary: Approximately 30%-70% of nitrogen fertilizer applied to agricultural crops is lost. Consequently, multiple applications are required to compensate for this loss, which lead to increased cost and environmental damage. To reduce fertilizer loss, we developed bio-based matrices containing clay, lignin, beeswax, and latex that can release nitrogen-containing urea over multiple weeks. The release rates can be controlled by varying the proportions of the bio-based components. These matrices lead to a more efficient and economical method for applying nitrogen fertilizers to crops.

Technical Abstract: Urea pearls were encapsulated in cloisite-based matrices using different natural materials (lignin, beeswax and latex) to control the release of urea over time. It was found that all cloisite-based fertilizer tablets showed better release profiles than neat urea tablets. The best release profile was obtained when latex and wax were added to the cloisite matrix (cloisite:wax:latex ratio of 4:1:1). This composite had the highest work value and also showed low porosity values. The increase in firmness of the sample was an indication of the good compatibility between these materials suggesting an extended availability and efficient utilization of the applied urea in fields.