SEMIEMPIRICAL INFILTRATION EQUATION FOR FURROW IRRIGATION SYSTEMS

A semiempirical equation for cumulative infiltration in a furrow irrigation system was developed using an empirical wetting front advance equation and a volume balance technique. This equation was verified using the field data obtained in a Yolo loam soil (Typic Xerorthents) planted with a furrow irrigated tomato crop. Two distinct cases were considered: (1) furrows with deposional crusts at the bottom (uncultivated); and (2) furrows in which a crust breaking device was used to remove the deposional crust (cultivated). The semiempirical equation for cumulative infiltration correlated to the measured cumulative infiltration very well for both the calibration and the prediction data set. The coefficient of multiple determination was 0.997 for the cultivated furrows and 0.998 for the uncultivated furrows. Simulation studies were conducted to determine the possible use of this equation in furrow irrigation management.