LABORATORY EVALUATION OF VARIABLE WATER APPLICATION WITH PULSE IRRIGATION

A linear-move irrigation system was recently installed at the Colorado State University Agricultural Research, Development and Education Center (ARDEC). This machine will be used for small plot studies emphasizing conjunctive management of irrigation water and chemicals for both protection of groundwater quality and for optimizing production from limited water supplies. It is necessary to control water and chemical applications both along the lateral line and in the direction of travel because of the many small plots under the machine. Laboratory tests showed that electrical solenoid valves can be pulsed as a means of obtaining a wide range of-application rates to plot areas, so long as pulse frequency is less than I min. We concluded that water application under pulsed conditions was directly proportional to the fraction of time the valve was opened, and that the technique is viable for controlling applications to research plots.