PERFORMANCE OF TRAVELLING GUN IRRIGATION MACHINES

A large proportion of the Australian sugar crop is irrigated by travelling gun irrigation machines, including approximately 60% of the crop in the Bundaberg district. However, little is known of their performance in the field. To redress this deficiency, trials were conducted in the Bundaberg region to determine the performance of travelling irrigators under various conditions and to enable assessment of the opportunities for improving performance. Depths of water applied by one pass of the machines were measured using a linear array of catch cans in a single leg test. The Christiansen uniformity coefficient (CU) was used to benchmark the performance. The influence of wind speed and direction (relative to the travel direction of the machine), operating pressure, and nozzle size and type were determined. In all cases tested, the uniformity of applications was sub-optimal. Optimum lane spacings were calculated.