New Controlled Release Fertilizer Systems Derived from Biomass

Studies have shown that up to 70 percent of conventionally applied fertilizer goes unutilized by plants and becomes a contaminant of surface and ground (drinking) water. Fertilizer run-off in surface water leads to oxygen depletion of streams, lakes, and other bodies of water. Without oxygen, the water becomes uninhabitable for fish and other aquatic organisms. In addition to the negative environmental impacts, fertilizer waste through leaching increases farm expenditures for fertilizer materials, labor, and fuel due to the need for multiple applications of fertilizer. As the costs of traditional fertilizers continue to rise and environmental regulations become more stringent, more attention will be directed toward developing efficient fertilizer technology. Cost competitive fertilizer materials with greater efficiency in nutrient delivery would be environmentally and economically advantageous, providing significant savings to American farmers. Controlled-release fertilizers, capable of delivering plant nutrients in a controlled manner over time, are the most promising fertilizer technology. However, controlled-release fertilizers currently command a 3x to 10x premium over traditional fertilizers, making them too expensive for most crop applications. Therefore, new technology is needed to make controlled-release fertilizers cost competitive with conventional fertilization strategies. This Phase I project outlines new controlled-release fertilizer systems which utilize a biodegradable polymer matrix made from renewable resources. The polymers targeted in this project will be derived from xylaric acid which is produced in one chemical oxidation step from xylose (wood sugar), a carbohydrate component of biomass. To demonstrate the feasibility of using xylaric acid-based polyamides as the basis for controlled-release fertilizer systems, this project sets the following objectives a) to optimize a new, low-cost polymerization method for condensing xylaric acid with select commercially-available diamines, b) to develop a protocol for encapsulating conventional fertilizer materials within the xylaric acid-based polyamides, and c) to measure the nutrient release from the polymer encapsulated fertilizers. We expect the results from this project to help bridge the economic gap between conventional and controlled-release fertilizers, making the latter more affordable through the use of a superior polymeric material for encapsulating fertilizer components. At the conclusion of this project we expect to have platform technology for preparing a number of polymer encapsulated fertilizer materials derived from xylaric acid, select diamines, and conventional fertilizers. This will mitigate large expenditures in the fertilization process and curtail environmental impacts associated with conventional fertilizing procedures.