[Truncated abstract] Improved irrigation performance can deliver both environmental and economic benefits from the production of irrigated crops. The objective of efficient irrigation design is to increase water application efficiency, distribution uniformity and requirement efficiency, while reducing deep percolation and tail water drainage losses. By improving system efficiency water losses are minimised and crop yields may be increased. Efficient systems also lead to better environmental and economic outcomes for the producer. The Harvey Irrigation Area (HIA) in the southwest of Western Australia is unique in the State because water is provided without pumping costs. Border-check irrigation is currently the main method of water application used in dairy farming to produce grass and has been reported as having a low irrigation efficiency of 50%. Different options to improve irrigation efficiency are available. The objective of these options is to uniformly replenish root zone moisture reserves whilst minimizing water losses via deep percolation below the root zone and tail water drainage from the end of the field. Options to achieve these objectives include increasing inflow rate, reducing field length and selecting the appropriate cut-off time for the input supply of water. These three options can be manipulated simultaneously under conditions of ‘surge’ flow, if soil characteristics are known. This research investigates the effects of two different flow regimes on the performance of border-check irrigation using the Surface IRrigation MODel (SIRMOD) as a design tool. Continuous flow and surge flow were compared in order to provide guidelines for improving the efficiency of border-check irrigation in the Harvey Irrigation Area.
|Publication status||Unpublished - 2011|