Spatially-varying infiltration, geometry, and roughness along with spatially- and temporally-varying wetted perimeter effects on furrow advance and application uniformity were investigated. Extensive field-gathered infiltration, geometry, roughness, and advance/recession data was collected and used to calibrate and validate the simulation model.

Model simulation was done for both a single furrow as well as on a field-wide basis. Variable furrow inflow was incorporated into the field-wide analysis. Model simulations were evaluated to determine the importance to irrigation performance of each spatially-varying model input. Flow rate, infiltration function variability, furrow geometry and furrow roughness influence irrigation performance in decreasing order of importance.