Evaluation of Water Management and Water Consumption in a Frequent and Small Amount Irrigated Field

― A case study of the soil water movement simulation for irrigation planning ―

Abstract

The aim of this study is to predict the soil water condition and flux and evaluate applicability of a method to quantify water consumption in a frequent and small amount irrigated field. A numerical model was introduced using HYDRUS 2D/3D to predict the soil water movement under frequent and small amount irrigation. To verify the model accuracy and obtain input data for the numerical model, field measurement was performed in a greenhouse where cherry tomato was cultivated. The simulated result of soil water flux indicated that the downward soil water movement after irrigation occurred in the vicinity of surface layer and drainage of gravitational water did not occurred in deeper layer. The method to quantify the water consumption in one-dimensional crop field could apply to frequent and small amount irrigated field because the horizontal soil water movement was quite small compared to vertical soil water movement.