Preparation and Properties of Starch-Based Polymer Coated Urea Granules

A new type of controlled release fertilizers was prepared with the bio-based polyurethane from liquefied starch as a biodegradable coating materials. We studied the nitrogen release characteristics of the polymer-coated urea (PCU) applied in both water and soil. The morphology and chemical structure of PCU coating materials was investigated by SEM, AFM and FTIR. The biodegradability of PCU coating after buried in soil was studied. The results showed that PCU coating more effectively reduced nitrogen release rate than starch coating. The PCU coating materials can biodegrade in soil. This indicated that the low cost PCU products from the liquefied starch are expected to be used in agricultural and horticultural applications.