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 Cen ter (ARDEC). This machine will be used for small plot studies emphasiz ing conjunctive management of irrigation water and chemicals for both protection of groundwater quality and for optimizing production from l imited water supplies. It is necessary to control water and chemical a pplications both along the lateral line and in the direction of travel because of the many small plots under the machine. Laboratory tests s howed that electrical solenoid valves can be pulsed as a means of obta ining a wide range of-application rates to plot areas, so long as puls e frequency is less than I min. We concluded that water application un der pulsed conditions was directly proportional to the fraction of tim e the valve was opened, and that the technique is viable for controlli ng applications to research plots.