Author(s)

K. L. Khatri & R. J. Smith

Abstract

A simple real-time control system for furrow irrigation is proposed that predicts the infiltration characteristic of the soil in real time using data measured during an irrigation event, simulates the irrigation and determines the optimum time to cut-off for that irrigation. The basis of the system is a new method for estimating the soil infiltration characteristic under furrow irrigation, developed previously by the authors, that uses a model infiltration curve, and a scaling process to predict the infiltration characteristic for each furrow and each irrigation event. Using this method, infiltration parameters were calculated for two different fields. The SIRMOD simulation model was then used to simulate irrigation performance under different model strategies, framed to assess the feasibility of the real time control strategy. The simulation results showed that the system is feasible and that the scaled infiltration is suitable for use in real-time control. The results further indicated that under simple real time control the irrigation performance for the two fields could be improved greatly with substantial reductions in the total volume of water applied. Keywords: surface irrigation, real-time control, simulation, optimisation, application efficiency, infiltration scaling. 1 Introduction The performance of surface irrigation is a function of the field design, infiltration characteristic of the soil, and the irrigation management practice. However, the complexity of the interactions makes it difficult for irrigators to identify optimal design or management practices. The infiltration characteristic of the soil is the

Keywords

surface irrigation, real-time control, simulation, optimisation, application efficiency, infiltration scaling.