Develop bio-asphalt-based controlled release nitrogen fertilizers for improving nitrogen use efficiency

摘要

One of the major reasons causing current low nitrogen use efficiency (NUE) in crop production is poor synchronization between fertilizer application and demand of crop growth. Crop like corn has different nitrogen (N) demand during different growing stages. The goal of this study is to develop a bio-asphalt-based controlled release nitrogenous fertilizer (BCRNF) to control N release to synchronize with N demand of corn growth in different stages. The bio-asphalt produced from hydrothermal liquefication of agricultural wastes such as corn stover was used as N carrier in fabrication of BCRNF. Granular ammonium sulfate was either mixed or coated with bio-asphalt to control N release. Different BCRNF samples were tested to examine their N release patterns in water. The results showed that the N release patterns of BCRNF were significant affected by the fabrication conditions. The bio-asphalt melting temperature significantly affected the N releasing time of BCRNF in water. The releasing time of 80% N for the BCRNF sample prepared at 230 °C was more than 20 days. The performance of other BCRNF samples also demonstrated the concept of controllable N release if ammonium sulfate were properly mixing or coating with bio-asphalt. Although further researchis needed, the BCRNF has shown very promising potential in the control release fertilizer market for corn production.