Selection and Development of Suitable Mathematical Model for Evaluation and Improvement of Furrow Irrigation

Abstract

Water infiltration and storage under surface irrigation are evaluated, based on the initial soil water content and inflow rate as well as on the irrigation parameters and efficiencies. For that purpose a field experiment was conducted at demonstration Farm College of agricultural Studies – Sudan university of Science and Technology in clay soil. To improve the application efficiency of furrow irrigation system by using cut back technique. The experiment was conducted at field with length of 85m and width of 50 m and the spacing between furrows was 1.5 m. using parshal flume to applied three flow rate (8.16, 7.72, and 6.37 L/s)with different slops (26%, 17%, 15%). Under field condition were evaluated and improving the water management. From the results indicated that for conventional irrigation without cut back high rate of application efficiency (53.66%) was obtained under the flow rate and slope 8.16 l/s and 12% respectively. To evaluate the filed performance for conventional irrigation system using the data collected from the filed entered to a computer program including Muskingum, Skogerboe and Clemmence Models the results show that the data obtained from the field compared to the three computer models give application efficiency value similar to the Muskingum models model. To improve the application efficiency using the cutback irrigation method under the same condition of conventional irrigation system by reduce the flow rate at half when reached 3/4 of the furrow length. The flow rate and the slope which were archived high application efficiency were 12 % and flow 6.37 L/sec was higher that obtained at the 35% conventional irrigation system by cut-back. Compare the actual field data for cut back irrigation method by entered to the a computer program including Muskingum and Skogerboe model, the results show that the field data was to be similar to Skogerboe model. In this study developed and built extension of computer program for cut back irrigation method at Muskingum model. To validate the new computer model built at the basis of storage equation compare the actual field data for cut back irrigation method to a computer program including Muskingum, Skogerboe and clement model , the new computer model give high application efficiency more the two computer model it is worth to be mentioned Skogerboe , model is closest. Key words: furrow irrigation, cutback, application efficiency, simulation model