Abstract

                                An automatic surge irrigation system was fabricated and field tested to establish its efficacy under on-farm irrigation water management. The system was based on sequential operation. A time switch and an electromagnetic valve were the main components of the system. Field evaluation of this automatic surge irrigation system was carried out at Tamil Nadu Agricultural University, Coimbatore. Efficacy of automatic surge irrigation system over continuous flow system was experimentally evaluated in paired row furrows of 120 cm width in terms of waterfront advance times, infiltration patterns and soil moisture distribution efficiencies. Automatic surge flow was found to make the soil reach its basic infiltration rate much quicker, 35 to 50 percent of the time elapsed in continuous flow. This facilitates quicker waterfront advance resulting in more uniform storage and distribution of soil moisture from head to tail end of the field with minimum losses. Surge flow in 160 m long furrow was found to cause 48 percent reduction in the advance time as taken by the continuous flow and it took 59 percent of the net duration of irrigation to advance to the tail end. Though it is better than continuous flow in saving advance time the greater proportion for its advance time (59%) over the net irrigation time limits its application up to 120 m long furrows only. The longitudinal distribution of soil moisture after irrigation was found to be more uniform in furrows under automatic surge flow compared to continuous flow.

Key words : Automatic surge irrigation, paired row furrow, soil moisture, waterfront advance, cycle time, cycle ratio.