Optimizing Agricultural Nitrogen Management: Conveying the Nitrogen Cascade to Stakeholders

3 - 6 months

Develop an approach to communicate fertilizer optimization to the farm community, balancing agronomic production, greenhouse gas emissions and water quality.

Nitrogen fertilizers have provided great benefits to agricultural production and human nutrition across the globe.  Yet in many cases, fertilizer application exceeds crop uptake, releasing nitrogen to air and water with costs to human health and the environment that are external to the agricultural economy.  Despite the long history of research on agricultural N management, fertilizer recommendations often do not consider optimization of agronomic and environmental endpoints. 

Over the last few years, EPA has been working with local farmers to measure nitrate leaching from nearly 20 production farm fields in the southern Willamette Valley of Oregon.  This substantial dataset includes information on fertilizer N inputs, crop N uptake and nitrate leaching from each field.  Some fields also have data on N2O emissions and N application gradients through a collaboration with Portland State University.  The cropping systems studied include vegetable crops, peppermint, orchard crops and grass seed.  We also have data on former farms converted to conservation areas to provide an estimate of background N leaching.   Together, these data sets allow us to develop a new approach for estimating the optimal N application rate for several crops in the area. 

Problem:  We propose to use the data collected from 2014-2020 in southern Willamette Valley farm fields to develop a case example of balancing maximum agronomic production with associated nitrogen release to the environment.  We will develop this optimization approach in conjunction with PSU colleagues, Oregon State University extension staff, colleagues from the Oregon Department of Agriculture and staff from local Soil and Water Conservation Districts. 

Scope and Goals:  We are seeking a student to take an active role with the EPA research team including engaging with university and local partners (mentioned above). With EPA mentoring, the student will develop a case example for the optimization effort, likely focused upon grass seed crops. Grass seed is a predominant crop in the region, and we have the most complete data sets associated with this crop. The GRIP student would take the lead for this effort, with guidance from EPA mentor(s) and gain experience in communicating this optimization approach to local stakeholders within the farm community.  The student would lead a publication on this approach, using data from the SWV studies as a case example of an optimization. 

The student will learn about agricultural N management, the nitrogen cascade, and Groundwater Management Areas as an approach to improve drinking water quality in the southern Willamette Valley.  The student would organize meetings with local stakeholders such as staff from Oregon Department of Agriculture and Department of Environmental Quality about the connections between agriculture and water quality in the region.  They would have the opportunity to learn and practice the communication of surrounding the connections between agriculture and the relationship to water quality and other environmental emissions. 

J. Renée Brooks (Brooks.ReneeJ@EPA.gov)