A three-year study was conducted from 2016 to 2018 to assess the water quality effects of high fertilization rates on maize. The study was conducted in a 1.44 ha field located on the University of Georgia’s (UGA) Tifton Campus, in the southeastern Coastal Plain of Georgia, USA. Two fertilizer treatments were applied based on the University of Georgia Extension Service (CE) and the Georgia maize growers (CG) recommendations for achieving high yields. Conventional tillage was used in 2016 while conservation tillage was used during the following two years. Throughout the course of the study, groundwater and surface runoff samples were collected. Implementation of conservation tillage in the second and third growing seasons resulted in reduced surface runoff and increased infiltration. Statistically higher NO3-N concentrations in groundwater resulted from the CG treatment and NO3-N concentrations in groundwater increased over time. The data collected from the field study were used in to simulate the water flow and solute transport with the HYDRUS-1D model. Groundwater data from 2018 were used to calibrate the model while the data from 2016 and 2017 were used for evaluating the model. In general, the correspondence between simulated and observed data was good especially in 2016 and 2018. Additionally, after HYDRUS-1D was successfully calibrated and evaluated, it was used in parallel with the DSSAT CERES Maize model to evaluate three maize irrigation scenarios. The scenarios were the University of Georgia Checkbook Method, a sensor-based method, and rainfed production. The simulation results indicated that the sensor-based scheduling method could achieve higher maize yields along with lower water and NO3-N leaching.