Performance and Irrigation Scheduling Of Center Pivot Systems in River Nile States Sudan

Abstract

This study was conducted at Atbra Farm of the Arab Company for Crop Production where center pivots are used for producing alfalfa as a forage crop for export. The experiments were run during the summer of 2007. The field work included analysis of soil physical and chemical properties, evaluation of the performance of center pivot irrigation system, the irrigation scheduling practiced in the farm and crop water requirement. The results showed that the soil suits the application of center pivot irrigation system. The low levels of both macro and micronutrients suggest the need for addition of nitrogenous phosphatic and potassic fertilizers together with foliar spray of micronutrients. The results also showed that the uniformity coefficient using Christiansen (Cu) and Heirman and Hein (CuHH) methods was relatively low and was found to be 84.14% and 85.32% respectively, which were relatively lower than the accepted 90%. The distribution uniformity (Du) was found to be 80% at 50% speed which is considered below the acceptable value. The results also showed that the application efficiency is 76.71%. For proper irrigation scheduling a recent innovation having a trade name (watermark) coupled with a special resistance digital meter were used for monitoring the soil moisture and the results were exhibited in graphical form. It was evident from these results that when appropriate scheduling programs are followed as by using the watermark three to four irrigations can be eliminated which will reduce the fuel cost and finally the total cost of operation of the center pivot irrigation system.