Universities CoUnCil on Water resoUrCes JoUrnal of Contemporary Water researCh & edUCation issUe 139, pages 7-14, april 2008 Understanding Nutrient Cycling and Sediment Sources in the Upper Susquehanna River Basin Peter B. Woodbury 1 , Robert W. Howarth 2 , and Gail Steinhart 3 1 Department of Crop and Soil Sciences, Cornell University, 2 Department of Ecology & Evolutionary Biology, Cornell University, 3 Albert R. Mann Library, Cornell University H uman activity has increased the amount of nitrogen fowing into surface waters and estuaries in the northeastern U.S by 10- fold or more (Howarth et al. 2005). In estuaries such as the Chesapeake Bay, such large increases in nitrogen are severely damaging populations of aquatic plants and animals and also increasing harmful and toxic algal blooms. At global and national scales, agriculture is the major source of nitrogen pollution. However, atmospheric deposition is also a major source in many regions, and it contributes 25 to 50 percent of the nitrogen inputs to the Chesapeake Bay. The Susquehanna is the largest U.S. river draining to the Atlantic, the largest tributary of Chesapeake Bay, and the single largest source of nutrients to the main stem of the Bay. Therefore, better understanding of the sources and sinks of nutrients and sediment in the Susquehanna River watershed will support better management of nutrients and water quality in the Chesapeake Bay. The Agricultural Ecosystems Program is a multidisciplinary program of the College of Agriculture and Life Sciences at Cornell University designed to increase our knowledge of the sources and sinks of nutrients and sediments in the New York portion of the Susquehanna watershed. Such knowledge will beneft not only the Susquehanna River watershed and the Chesapeake Bay, but will be valuable for improving understanding and management of nutrients in many other portions of the U.S. The program is truly multi-disciplinary, with forty participants from seven academic departments of Cornell University as well as Cornell University’s Mann Library, and representatives of six other academic or governmental organizations, including the Upper Susquehanna Coalition, a multi-agency group focused on improving water quality in the Upper Susquehanna River Basin. Program Objectives Our program has the following fve objectives: Improve estimates of the amounts of nitrogen, phosphorus, and sediments moving into the upper Susquehanna River, and ultimately to the impaired Chesapeake Bay. Determine which factors control nutrient pollution in rural landscapes containing a mixture of forest and agricultural land uses. Determine the importance of agricultural sources compared to other sources of nutrient pollution. Determine how climate variability and climate change are affecting nutrient pollution. Gain knowledge, tools, and techniques that will help maintain agricultural productivity and environmental quality throughout the northeastern U.S. and beyond. The following approaches are used to promote creative research across disciplines: Improve knowledge of key nutrient cycling processes by funding innovative feld and laboratory studies via grants to Cornell researchers. Leverage and expand upon a) existing agricultural ecology research at the Harford 1. 2. 3. 4. 5. 1. 2. 7 UCoWr JoURnAL of ContEMpoRARy WAtER RESEARCh & EDUCAtion entire.indd 7 3/17/2008 11:38:54 AM