Presentations

Agricultural practices can affect groundwater most directly by over-drafting aquifers and percolating contaminants. Both of these possibilities are mitigated by irrigation practices. We discuss the role of irrigation system operations and maintenance in the broadly observed contamination of aquifers with agriculturally-source nitrogen. Though rarely addressed in the literature, system maintenance is shown to be pivotal to groundwater quality protection. Benefits of such efforts include substantial economic cost reductions and yield increases. New soil distributed moisture measurement methods are presented which point the way to ever more precise management of irrigated lands. Examples of the issues discussed are drawn from field projects conducted over the past 10 years in Oregon.