Project Summary
This work systematically evaluates the mechanisms and environmental benefits of using duckweed to capture nutrients from agricultural waste sources within the context of the nutrient-impaired Chesapeake Bay Watershed. Rather than nutrient treatment being a burden, this work will demonstrate how leveraging duckweed can generate critical economic value when returned into the agricultural system as a protein-rich feed supplement for dairy cattle or as a soil amendment for crop production. The result of the transdisciplinary effort is the creation of a unique and sustainable N bioeconomy with global relevance.
Intellectual Merit
Non-point source pollution remains a critical cause of impairment to water bodies, despite decades of investment in management strategies. Further, this pollution source is critically linked to providing food to growing populations. There is clearly a need for novel solutions that can effectively address this wicked problem. The massive amounts of nutrients (ex., C, N, and P) that are currently released into the environment as waste have the potential to be recovered and transformed from a liability into an asset through photosynthesis, industry insight, and ecologically-informed engineering design aimed at circularity. Fast growing aquatic plants like duckweed have the potential to enable local communities to simultaneously treat their own polluted water and retain nutrients that underlie the productivity of modern agriculture, reducing farmers’ operating costs and increasing the likelihood of adoption and implementation of these management practices. Producing soil amendments and feed supplements near the point of use reduces energy consumption and greenhouse gas emissions that would otherwise be required for their production and transportation, and the retention of nutrients in soils increases soil fertility, reduces eutrophication, and contributes to global ecosystem health. In this project, a series of interconnected experiments are used to evaluate the mechanisms of nutrient recovery and upcycling via duckweed, as well as explore the best processing and implementation practices for duckweed as an animal feed and soil amendment. Both techno-economic and life cycle analysis are used to evaluate the overall cost efficiency and environmental sustainability of the system. Focus groups and surveys with local stakeholders in the Chesapeake Bay Watershed will ensure feasibility of the approach and prepare for pilot implementation. This circular bioeconomy strategy represents a new paradigm for nutrient management that could help decrease the severity of the looming food-energy-water crisis by making ecological water treatment and regenerative agriculture more practical while simultaneously reducing global warming.
Broader Impacts
This research is particularly relevant to meeting three of the Grand Engineering Challenges for the 21st Century, namely: providing access to clean water, managing the nitrogen cycle, and restoring and improving infrastructure. The proposed work comprehensively demonstrates the feasibility of a new treatment technology for non-point source nutrient pollution as part of a larger nitrogen bioeconomy, providing local solutions to global problems. In this improved bioeconomy, waste nutrients from agricultural runoff are recovered and upcycled into valuable agricultural products, while simultaneously supporting the global critical need to reduce greenhouse gas emissions. Outreach with local farmers, landowners, and extension agents is integrated into the project to both pilot the proposed strategy and ensure the feasibility, acceptance, and appropriate communication of the approach. Teams of undergraduate and graduate researchers will be recruited from diverse backgrounds, and trained in both the science and science communication of transdisciplinary collaboration, empowering them to enter the workforce armed with new approaches and abilities to work across disciplinary boundaries to tackle highly complex food-energy-water nexus challenges.