Simulation of Soil Water Movement in Upland Soils Under Sprinkler and Spray Hose Irrigation Using HYDRUS-1D

PurposeThe simulation of water movement in the soil is an efficient way to obtain information about soil water dynamics. This predicting information is required to irrigate appropriate water to crops at various environmental conditions and growth stages. Fountain irrigation is one of the most common surface irrigation methods. The objective of this study is to validate HYDRUS-1D for modeling water movement in fountain irrigation by evaluating the measured soil water contents from field experiments.MethodsThe HYDRUS model was used for simulating water flow with hydraulic parameters and irrigation amounts. Field experiments were conducted on a sandy loam soil where soybean was grown. To measure the soil water contents, FDR sensors were installed each vertically 10 cm, 20 cm, 30 cm, and 40 cm underneath the soil surface. Precipitation and environmental data were measured using a weather station at the experimental site.ResultsThe predicted values for the whole zone were more accurate at spray hose irrigation (RMSE = 0.023, R2 = 0.623, E (coefficient of efficiency) = 0.597) than at sprinkler irrigation (RMSE = 0.041, R2 = 0.663, E = 0.416). Overall, the predicted and measured values were agreed well in fountain irrigation.ConclusionsThe HYDRUS can be used as a useful tool to simulate soil water movement in upland soils and evaluate irrigation practices. This precision water management could improve the quality and productivity of crops.