From field to groundwater: Quantifying crop nitrogen budgets, performance metrics and nitrate leaching in the southern Willamette Valley, OR.

This presentation will cover recent research on nutrient inputs, agricultural management and nitrate concentrations in soil solution and groundwater in the southern Willamette Basin’s Groundwater Management Area.  The primary topics for this presentation will be an analysis of the trends in well water nitrate concentrations from 2006-2018 in the GWMA area, using data from the Oregon Department of Environmental Quality's water sampling program.  The primary finding is that despite a fair amount of attention and effort related to reducing groundwater nitrate contamination, well nitrate concentrations have increased since about 2012.  EPA will also present the results of a RARE project completed at the end of FY21 that measured nitrate leaching from production farmland in order to understand how on the ground practices influence nitrate leaching.   This presentation will allow us to communicate with EPA agricultural advisers and others about the findings, explanations, implications and application for our study results.  

Impact/Purpose

EPA CPHEA's Jana Compton and Julie Weitzman (ORISE Postdoctoral Fellow) were invited to present an update on research ongoing in the Southern Willamette Valley GWMA for the Oregon Department of Environmental Quality (DEQ) Groundwater Technical Advisory Team.  This meeting is for a group of DEQ employees whose work relates to groundwater, which convenes twice a year to get updates.  This group also advises DEQ's Statewide Groundwater Quality Monitoring Program.  DEQ is interested in this work as it relates to the  southern Willamette Valley Groundwater Management Area.  Jana Compton will be presenting on the Partnership to Improve Nutrient Efficiency (PINE) study and some of the results on the nitrate well monitoring data.  Julie Weitzman will be presenting on the related deep soil nitrate leaching project.  The title of their presentation is “From field to groundwater: Quantifying crop nitrogen budgets, performance metrics and nitrate leaching in the southern Willamette Valley, OR”. This work supports SSWR RA6 Product 6.3.2 "Integrated approaches in community nonpoint source nutrient management".  

Citation

Compton, J., J. Weitzman, J. Renee Brooks, A. Henning, S. Pearlstein, R. Coulombe, L. Erban, B. Hatteberg, C. Piscitelli, J. Selker, B. Faulkner, P. Mayer, E. Peachey, W. Rugh, AND S. Hutchins. From field to groundwater: Quantifying crop nitrogen budgets, performance metrics and nitrate leaching in the southern Willamette Valley, OR. Oregon Department of Environmental Quality (DEQ) Groundwater Technical Advisory Team, Corvallis, OR, December 09, 2021.