Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Agricultural Engineering

The effect of water application uniformity on crop yield uniformity (CU yield) from a center pivot irrigation system operating under field conditions was analysed. A field experiment was performed during summer and winter season (2015), located in Elmina, Alexandria and Ismailia (Egypt), in area of 31.3, 30.7 and 63ha, respectively, field irrigated with a center pivot system. The objectives of this paper are to study water application uniformity (CU), run off and wind drift evaporation losses (WDEL) with two types of fixed spray plate sprinklers (FSPS): Senninger (LND-UP3&Inv. wobbler) and Nelson (D3000) both installed at the same height (2 m above the ground). Different predictive equations of WDEL were proposed for combinations of the two irrigation systems and the two operation times. The results show that for two season, Senninger had higher values of CU (80{u2013}85%) than the Nelson (75-80%). In sprinkler irrigation, a CU value of around 80% for each types of sprinklers. The mean value of runoff 29% from water applied, WDEL were significantly higher with nelson than with senningers. The lowest WDEL values were registered ranging from 12.35 to 12.55% under winter and summer operation conditions, respectively. Mean yield for potato and sugar beet was 32.7 and 91.2 ton/ha., respectively. These results were obtained for an average wind speed and air temperature of 4.4 m/s, 3.5 m/s and 31.3C0, 18.3C0 at summer and winter season, respectively

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