Simulation of a collective solid-set sprinkler irrigation controller for optimum water productivity

Abstract

The modernization of irrigation districts in Spain is based on the construction of collective pressurized networks equipped with remote control systems. In this paper, a simulation approach is used to explore the benefits of introducing a collective solid-set irrigation control software. The controller works in combination with a district management database, real-time evapotranspiration and meteorology information, and a remote control system. Controller decisions are based on the simulation of sprinkler irrigation performance and on crop-water balance. The decision to irrigate a plot can be guided by the use of two simulation parameters: the estimated application efficiency of the irrigation event (heavily affected by wind speed) and a crop-water stress index. Simulation experiments were performed in a district located at the Ebro basin of Spain. The collective controller resulted in water conservation (with respect to the current situation) of 2,234 and 4,664 m3ha-1 for corn and alfalfa, respectively, and in an increase in water productivity of up to 91%. Although additional research is needed to produce a reliable collective controller, these preliminary results are encouraging.