Abstract
Dryland crops are planted in plastic-mulched ridges to suppress weed growth and support early plant emergence because of increased soil temperatures in the ridges. However, effects of plastic-mulched ridges on soil water dynamics in humid areas have not yet well inves-tigated. This study aimed to evaluate soil water flow in a field covered with plastic mulch using the HYDRUS (2D/3D) model. Observed soil water contents in an egg-plant (Solanum melongena L.) filed with plastic-mulched ridges in the summer of 2012 were validated with the wa-ter flow model. Boundary conditions and two parameters of the root water extraction model were investigated for several simulation scenarios. A reasonably good agree-ment between the model-predicted and observed soil wa-ter contents in plastic-mulched ridges was found. Simu-lation results revealed the water flows in plastic-mulched ridges during rainfalls. Soil water contents were higher in ridges without mulch than in ridges with mulch. Moreover, soil water contents fluctuate greater in bare ridges than in mulch covered ridges. We concluded plastic mulch at the soil surface could moderate the water content increase in the soil profile during the rainfall in the humid area.
