Predicting Water Distribution and Optimizing Irrigation Scheduling in Turfgrass Management Using HYDRUS-2D

The increasing reliance on water resources has necessitated improvements in turfgrass irrigation efficiency. This study aimed to compare measured field data with predicted data on irrigation water distribution in turfgrass rootzones to verify and enhance the accuracy of the HYDRUS-2D simulation model. Data were collected under controlled greenhouse conditions across unvegetated plots with two- and three-layered rootzone construction methods, each receiving 10 L m−2 h−1 of water for 1 h via subsurface drip irrigation (SDI) or sprinkler (SPR). Water content was monitored at various depths and time intervals. The hydraulic soil parameters required for the simulation model were determined through laboratory analysis. To improve model performance, sensitivity analysis, and model calibrations were conducted. The results indicated pronounced effects of the rootzone construction method and associated irrigation system on model quality performance. The calibrated models demonstrated good agreement with measured data, achieving model efficiency values (NSEs) up to 0.81 for SDI variants and 0.75 for sprinkler-irrigated variants. The findings suggest that HYDRUS-2D has potential as a cost-effective and efficient tool for evaluating irrigation strategies in turfgrass areas, although further refinement may be necessary for specific rootzone/irrigation combinations. This modeling approach can contribute to the optimization of irrigation scheduling and water use efficiency in turfgrass management.