Innovations in Nature-Based Systems for Managing Nonpoint Source Nitrogen in Agricultural Ecosystems
A Warren Distinguished Lecture with
Matthew Charles Reid
Civil and Environmental Engineering, Cornell University
ABSTRACT
Runoff and leaching of agricultural nonpoint source nitrogen (N) are major drivers of water quality impairments around the world and are important sources of the greenhouse gas nitrous oxide (N 2 O). Nature-based treatment systems, including constructed wetlands and denitrifying bioreactors, are commonly used as cost-effective and sustainable tools for managing nutrients in agricultural discharges. However, the passive operation of nature-based systems means that treatment efficiencies are highly variable in time and depend on dynamic environmental factors including discharge and temperature. Additionally, there is often a lack of incentives for farmers to install treatment systems, limiting the uptake of these technologies. The first part of this presentation discusses the use of sensor feedback control approaches to stimulate biogeochemical N cycling processes in denitrifying woodchip bioreactors in response to real-time changes in environmental conditions. The second part of this presentation introduces a new initiative in New York State to grow rice in floodplains that had been taken out of agricultural production due to flood risk and the potential for rice paddies to serve as a form of constructed wetland to treat nitrate-contaminated agricultural discharges. This second part will include a discussion of how re-use of nitrate-contaminated water can offset fertilizer needs, suppress methane emissions, and decrease arsenic mobilization in paddy soils, contributing to a circular economy for agricultural nitrogen.
SPEAKER
Matthew Reid is an Assistant Professor in the Department of Civil and Environmental Engineering at Cornell University. He joined the faculty in July 2016. He received his Ph.D. in Civil and Environmental Engineering from Princeton University (2014) and a B.A. in Chemistry from the University of Chicago (2004). From 2004–2006 he taught high school chemistry with the U.S. Peace Corps in Karatu, Tanzania. Upon returning to the United States, he began working in the environmental sciences as a laboratory technician in chemical oceanography at Lamont-Doherty Earth Observatory. From 2014-2016 he worked as a postdoctoral scientist at the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland, on microbially driven arsenic cycling in rice paddy soils.