Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms.

In this work, biodegradable polymers were melt compounded with urea phosphate to fabricate "smart fertilizers" for sustainable agriculture. Urea phosphate (UP) is typically applied as a water-soluble fertilizer to treat phosphorus deficiency in high pH soils. Due to the low diffusion rate of phosphate through slow-release fertilizer coatings, phosphate supply has been considered the "bottleneck" for nitrogen-phosphorous-potassium (NPK) nutrients supply.