Channa Rajanayaka, Hamish McEwan and Bradley Monahan, in collaboration with Dr. Edmund Brown of the Waikato Regional Council, have successfully completed a three-year irrigation efficiency, water use and verification study in the Waikato region. During the first phase of the project, Draft Irrigation Guidelines for the region were developed using the irrigation simulation model, IRRICALC. The second phase of the project was dedicated to verifying the model against fieldbased measurements. These field investigations were conducted at six irrigated sites, which included four vegetable and two pasture sites. These sites cover a range of typical irrigation systems and management regimes, climate and crop types in the region. Production response due to irrigation at the field scale was also measured. The results from six farms over the three years showed the IRRICALC model was capable of accurately simulating the measured soil-water contents under a range of soil, climate and management conditions. This result also confirmed that the crop coefficients and parameters used in the modelling exercise for determining the irrigation guidelines were appropriate. Based on these findings, Aqualinc recommended that the Draft Guidelines values developed are appropriate for determining reasonable water allocation limits for irrigation in the Waikato Region.
展开▼
