The Agricultural Ecosysystem Program: Understanding sources and sinks of nutrients and sediment in the upper Susquehanna River basin
CALS Impact Project
We are working closely with the New York State Department of Environmental Conservation, the Chesapeake Bay Program, and the Upper Susquehanna Coalition to ensure that our research program will be useful to the stakeholder community to the largest extent possible. Project Director Robert Howarth represents the State of New York on the Science and Technical Advisory Committee of the Chesapeake Bay Program. During 2006, he gave briefings based in part on the project to the Commissioners of the Chseapeake Bay Commission, to the scientific staff at the White House, and at the National Atmospheric Deposition Program annual meeting.
impact statement issue
Over the past few decades, nitrogen inputs to Chesapeake Bay have severely degraded water quality. In the 1980s, Maryland, Virginia, and Pennsylvania, together with the U.S. Environmental Protection Agency (EPA), agreed to reduce the inputs of nitrogen from controllable sources to the Chesapeake by 40 percent. Despite significant efforts in these states, however, nitrogen inputs remain high, and water quality has improved little, if at all. As a result, the Chesapeake Bay Program, the Chesapeake Bay Commission, and the six states in the watershed of Chesapeake Bay have committed to further, stringent reductions in nitrogen, phosphorus, and sediment to the bay. New York state committed to this goal in March of 2004. The proposed cap for nitrogen fluxes from New York down the Susquehanna (to be reached by 2010) is 5,700 metric tons per year, a 26 percent reduction, according to the estimates of the Chesapeake Bay model. However, there is significant uncertainty in the current flux, as models differ in their estimation of the magnitude, and routine monitoring has only begun in the past year or two. Climate variability and future climate change may also tend to increase nitrogen fluxes in the Susquehanna, making it more difficult to reach the targeted reductions. Failure to meet this goal is likely to result in mandatory nitrogen and phosphorus reductions imposed by the EPA. Our research is designed to help find the most cost-effective way to reduce nutrient fluxes down the Susquehanna from New York.
impact statement response
The project began in the fall of 2005. In the first 1.5 years of the project, we have engaged 18 Cornell faculty and staff members and eight Cornell graduate students (in six departments) through a competitive selection process to begin research and modeling in the upper Susquehanna River basin. We have also expanded research at two core research sites, one agricultural and one for studying atmospheric deposition. Core research foci are the magnitude and fate of atmospheric deposition and the processes that affect nutrient losses from agroecosystems.
impact statement summary
Our goal is to gain a better understanding of the sources and sinks of nitrogen, phosphorus, and sediment in a large rural watershed of mixed land use, including agricultural and forest lands. The geographic focus is the Susquehanna River drainage basin and its tributaries within New York (an area of approximately 19,500 square kilometers), with an emphasis on the nitrogen and phosphorus dynamics of the agricultural and forested landscapes of the region. The Susquehanna is the largest U.S. river east of the Mississippi, the largest tributary of Chesapeake Bay, and the single largest source of nutrients to the main stem of the bay. Thus, better understanding of the sources and sinks of nutrients and sediment in the Susquehanna can lead to better management of nutrient fluxes from the landscape and thus water quality in Chesapeake Bay. The proposed research will also lead to a better understanding of the controls on nutrient pollution – particularly nitrogen pollution – in rural landscapes in general, and to insights on sustaining agriculture in the northeastern U.S. in a manner that best harmonizes with environmental quality. A major subtheme will be how climate variability and climate change influence the fluxes of nitrogen, phosphorus, and sediments from the rural landscape. Nitrogen is the primary focus, both because it is the primary pollution problem in coastal systems such as the Chesapeake Bay and because sources and sinks are more poorly understood for nitrogen than for phosphorus. Nonetheless, much can be gained from simultaneous study of the dynamics of nitrogen, phosphorus, and sediments.
