ELUCIDATING GROUNDWATER PROCESSES IN 3D FOR TARGETED MANAGEMENT OF AGRICULTURAL NITROGEN

The overall goal of this project is to evaluate the extent to which geological heterogeneity influences spatial patterns of nitrate reduction.The following objectives will be pursued:1. Co-develop a field investigation program with stakeholders (crop producers, landowners, Natural Resource Districts, industry representatives, etc.) using rust staining on center-pivot irrigation systems derived from aquifer waters as a guide to subsurface biogeochemical and hydrologic conditions.2. Build high-resolution, 3D framework models of vadose zone and aquifer properties at selected sites and interpret depositional environments (buried valleys and lakes, wind-blown silts and sands, etc.).3. Quantify nitrate reduction in the vadose zone and aquifer associated with various geological deposits and materials and predict fluxes with a 3D physics-based transport model.4. Co-develop a roadmap with stakeholders that will enable irrigation managers and crop producers to expand and implement targeted NO3-N management outside the immediate study areas.