This project utilizes simulation modeling combined with experimental data to better understand the fate of nitrogen in agroecosytems. The goal is to more efficiently use nitrogen (N), reduce N losses to the environment, and maintain or increase farm profitability. There are three subprojects: 1) Development of tools for growers to better manage fertilizer and manure N inputs for maize production. Current N recommendations do not account for the dynamic, variable soil N supply that is partly a consequence of a variable climate. We are using a dynamic simulation model to account for this variability and adjust fertilizer N recommendations accordingly. This is part of the Computational Agriculture Initiative and the Agricultural Ecology Program at Cornell; 2) We are using the model as an N assessment tool to better understand the sources of N loading in the upper Susquehanna Basin (as part of the Agricultural Ecosystems Program). We are also using the model to investigate the impact of alternative N management practices on N loading; 3) Apply the model to identify the potential for biofuels production (coppiced willow, switchgrass and reed canary grass) by ranking potential sites according to growing degree days, N availability (through mineralization of soil organic matter) and susceptibility to growth-limiting soil water deficits. This is a Hatch-funded project with Dr. Susan Riha as the lead researcher.

Economically and environmentally sound nitrogen management has become increasingly important to New York crop and dairy operations. Large increases in the price of nitrogen fertilizers, together with increasingly strict environmental regulations, make it critical that growers optimize N fertilizer use. As a result, New York growers and field crop extension staff have been requesting additional information and assistance with nitrogen recommendations for crop production. Our project is in response to these needs and has grown out of a substantial body of research done at Cornell. We are developing a tool to better assist growers with on-farm nitrogen management for crop production.
In addition, New York State is mandated to reduce N loading to the upper Susquehanna River Basin by almost 50 percent by 2010 in order to meet an EPA mandate to improve water quality in the Chesapeake Bay. To do this, there is a need for research into the sources of N losses (largely agricultural) and how to reduce those losses.
Finally, there is increasing interest in biofuels due to dwindling fossil fuels and global climate change. It is critical to identify the most productive areas where biofuels can be grown. New York State has significant land that could be converted to biofuel production. We will be assessing that land for potential productivity in order to maximize resources and return from investment.

We have developed a simulation model to track changes in soil nitrogen due to climate, management practices, crop, and soil type. Model simulations have been used since 2004 to provide recommended adjustments to the sidedress N recommendations for maize to field crop extension staff. A web-based version of the model will be available in 2008 where growers receive a recommended sidedress nitrogen rate via the web. We are also developing a new, more dynamic nitrate leaching index for better nitrogen management.
The model has been applied to selected areas in the upper Susquehanna River Basin to estimate current N losses from maize fields. Simulations were done and several growers practices were identified that could be altered to reduce nitrogen losses with little impact on maize yield. These data will be used to inform the basin-wide models currently under development and provide a more accurate picture of current N loading in the upper Susquehanna River Basin.
We are assessing potential biofuel production in St. Lawrence County as a prototype for a similar statewide assessment. Model input files have been developed for locations in the county and we have modified the model to simulate coppiced willow growth with N uptake. Willow biomass production under optimum nitrogen/water and the current estimated production will be assessed. The differences will be used to estimate site productivity and the nitrogen addition necessary for optimum biomass production.

We have received many requests to present our work at extension/growers meetings. We have also received specific requests from individual field crop extension staff for model simulations for the range of nitrogen management practices in their regions. The purpose is to use the results of the simulations to better educate growers in best management practices for nitrogen in the face of an increasingly variable climate. We have also been involved with Natural Resources Conservation Service, the Agricultural Research Service and colleagues at other land grant institutions to help develop a new nitrogen leaching index for different regions in the United States. We are assessing potential biofuel production in St. Lawrence County as a prototype for a similar statewide assessment. Model input files have been developed for locations in the county and we have modified the model to simulate coppiced willow growth with N uptake.