Characterization of water application uniformity, runoff and wind drift evaporation losses under center pivot irrigation system [electronic resource]

Includes bibliographic reference

The effect of water distribution uniformity (CU) on crop yield uniformity (CU yield) from a center pivot irrigation system operating under field conditions was analyzed A field experiment was performed during two seasons (2015), located in Elmina, Alexandria and Ismailia (Egypt), in 31.3, 30.7 and 63ha. respectively plot 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-UP3lnv. wobbler) and Nelson (D3000) both installed at the same height (1.5 m above the ground). Different predictive equations of WDEL were proposed for combinations of the two irrigation systems and the two operation times. Most equations use wind speed alone as an independent variable. although some use relative humidity or combinations of both variable plus air temperature. The results show that For two season, Senninger had higher values of CU (80-5%) than the nelson (75-80%). In sprinkler irrigation, a CU value of around 80% for each types of sprinklers can be sufficient to provide good crop yield uniformity, the mean value of run off 29% from water applied, WDEL were significantly higher with nelson (D3000) than with Senninger (LND-UP3-lnv. wobbler). The lowest WDEL values were registered with ranging from 14 to 19% under winter and summer operation conditions. respectively and mean yield for potato and sugar beet 32.7 and 91.2 ton/ha., respectively.
These results were obtained for an average wind speed of 4.4 m/s at summer and 3.5 m/s during the winter and were normally below 5 m/s.

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