Optimum Time Ratio for Maximum Application Efficiency in Furrow Irrigation

Time ratio, which is defined as the ratio of the time required for infiltration of net amount of water needed for the rootzone to the time when the water front reaches the end of the run, plays a key role in determining optimum furrow length to achieve maximum irrigation efficiency. In this study, a model was developed to determine optimum time ratio for maximum application efficiency in furrow irrigation. The model was then tested on potatoes grown furrows, 0.75 m wide and 120 m long, with three different slopes 0.5, 1.0 and 1.5% and each slope had three different inflow rates (0.75, 1.0, 1.25 l/s; 0.4, 0.5, 0.6 l/s; 0.3, 0.4, 0.5 l/s, respectively). Stations with 10 m intervals were marked along the furrows to investigate the advance and recession speed of each rate. The attained application efficiency was 64 % for an average soil. It was concluded that when the intake rate was slow the maximum application efficiency could be attained providing that a relatively longer furrow length was chosen or vice versa.