Infiltration parameters for furrow irrigation

This paper analyzes four different methods to determine for two furrow sizes (narrow=40 cm and wide=60 cm at the top) the infiltration constants of the Kostiakov model: the two-point method, furrow infiltrometer method, advance method, and one-point method. Based on representative data of conditions in Central Valley, Chillán, Chile, it was found that values of infiltration constants depend on the methodology employed in the measurements. The value for the constant B of the Kostiakov equation does not differ significantly for each method and furrow size. However, the value of A shows certain differences among the methods used, as well as between furrow size. The cumulative infiltration curves for narrow furrows are quite similar, independent on the infiltration technique used, and for wide furrows the cumulative infiltration curves depend on the infiltration method used. Using the Kinematic-wave model and the Kostiakov constants obtained with the advance model, simulate better the advance phase of the water front in the furrow. Additionally, for a wide furrow the two-point method shows the best fit. The poorest results were obtained using the Kostiakov constants determined from one-point method.