Effects of drip irrigation circuit design and lateral line lengths: I—On pressure and friction loss

Abstract

Laboratory tests were conducted at the Irriga-tion Devices and Equipment's Test Laboratory, The ex-perimental design of laboratory experiments was split in randomized complete block design with three replicates. Laboratory tests carried out on three irrigation lateral lines of 40, 60, 80 m under the following three drip irrigation circuit (DIC) designs; 1) one manifold for lateral lines or closed circuits with one manifold of drip irriga-tion system (CM 1 DIS); 2) closed circuits with two manifolds for lateral lines (CM 2 DIS), and 3) tradi-tional drip irrigation system (TDIS) as a control. The aims of the work were to study the effect of drip irrigation circuits (DIC) and lateral lines lengths (LLL; where): (LLL 1 = 40 m, LLL 2 = 60 m, and LLL 3 = 80 m) on pressure head (PH) and friction loss (FL). Regarding to LLL and accord-ing to PH values, DIC designs could be ranked in the following ascending order: TDIS < CM 1 DIS < CM 2 DIS. The differences in PH among DIC de-signs were significant at the 1% level. The de-pressive effects of LLL on PH could be ranked in the following ascending order: LLL 1 CM 1 DIS > CM 2 DIS and LLL 1 > LLL 2 > LLL 3 . The differences in FL among DIC and LLL were significant and the effects of interactions among DIC × LLL on FL were sig-nificant at the 1% level. The maximum and mi-nimum values of FL were obtained in the inter-actions: TDIS × LLL 3 and CM 2 DIS × LLL1, re-spectively. Therefore, the CM 2 DIS system is recommended for use where technically feasi-ble.