ECO-CBET: Foliar applied plant-activated nitrogen delivery agents for sustainable crop production.

Agriculture is critical to the economy, health, and national security of the United States (U.S.). Nitrogen fertilizers are widely utilized in agriculture to ensure an abundant and nutritious food supply for consumers and adequate financial returns for farmers. However, current soil nitrogen (N) fertilizer delivery routes and practices are not efficient with crops using less than 50% of the applied fertilizer loads.

This inefficient usage of N fertilizers continues to cause pervasive and vexing environmental problems in the U.S. and worldwide ranging from groundwater contamination, harmful algal blooms, eutrophication to the emission of gaseous N2O pollutants that negatively impact water and air quality. The overall goal of this project is to develop a foliar-based fertilizer delivery process that could efficiently deliver N and other nutrients to crops by applying the to the leaves directly rather than to the soil.

To advance this goal, the Principal Investigators of this project propose to encapsulate N fertilizers into functionalized nanoparticle carriers that deliver the nitrogen directly into the plant. These carriers will be designed to be sprayed onto the plant leaves. Special targeting ligands will be attached onto the surfaces of the N nanoparticle carriers and help guide them to the locations in the plants where they are needed.

The successful completion of this project will benefit society through the development of new fundamental knowledge that could be leveraged to guide the design and deployment of more efficient and sustainble N fertilizer delivery processes. Further benefits to society will be achieved through student education and training including the mentoring of five PhD students, one postdoctoral scholar, and ~18 undergraduate REU students.

Soil-based nitrogen fertilization of cropland has created severe imbalances in the nitrogen (N) cycle with unsustainable environmental consequences. Managing the N cycle is a perennial engineering grand challenge that can only be met by a radical transformation in the way that N fertlizers are applied to crops. The overall goal of this project is to transform the delivery of N and other nutrients to crops by enabling foliar-based application with highly efficient targeted and plant-activated N utilization.

Specific objectives of the project are to 1) Develop biocompatible carrier particles (N-carriers) for efficient N delivery that are derived from agricultural byproducts or earth-abundant minerals; 2) Graft plant-biorecognition molecules onto the N-carriers to enable the targeting of plant chloroplasts to increase N assimilation efficiency; 3) Develop molecular- and multi-scale transport models to predict N-carrier translocation and distribution through the leaf surface, and interactions with internal cell surfaces; and 4) Quantify the life cycle, environmental benefits, and risks of N-carriers relative to soil-applied N fertilizers. To achieve these objectives, the Principal Investigators of this project propose to converge and integrate ideas and tools from various fields/disciplines including nanotechnology, interfacial engineering, particulate and multi-phase transport, plant bioengineering, environmental engineering, and environmental sustainability.

The successful completion of this project has the potential for transformative impact through the development of more efficient and sustainable N fertilizer delivery processes that could advance the goals of an efficient and sustainable management of the N cycle.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.