Abstract
A field experiment was conducted in Jazeerah Al-Ramadi/Al-Hamidiyah research station (latitude33^o 27^’ 〖 11.9 〗 ^(՚՚)N, longitude 43^o 23^’ ^(՚՚) E (duration 2020. This study was conducted to investigate the effect of pipe types and emitters discharge on performance criteria of surface drip irrigation system. Therefore, a two factorial experiment was set as randomized complete block design with three replications. The first factor included the type of pipes and emitters, namely Turbo, GR and T-Tape. While the second factor involved the emitters discharge which consist of two levels i.e., 4 (D4) and 8 (D8) L.h-1. The irrigation system was initially evaluated in the field before planting by testing three operating pressures (50, 100 and 150 Kpa) to determine the actual discharge of the emitters closed to their design discharge (4 and 8 L.h-1) for each emitter to calculate the manufacturing coefficient of variation (CV), distribution uniformity and the discharge variation ratio at each operating pressure. Results showed that the best discharge (Closed to design discharge of 4 L.h-1) was obtained at the 50 Kpa operating pressure which gave 3.99,3.90 and 3.81 L.h-1 when using the T-Tape pipe and GR and Turbo emitter compare when the discharge of 8L.h-1 has been used which gave 7.96, 7.84 and 7.59 L.h-1 when the former pipe and emitters were used. The best coefficient of variation was observed when the T-Tape pipe and GR and Turbo emitter were used with discharge of 4 L.h-1 up to 0.1300, 0.2200 and 0.2600 compare to 0.1300, 0.2700 and 0.3500 when the same former pipe and emitters were used with discharge of 8L. h-1. Similarly, the best distribution uniformity was obtained when the T-Tape pipe and GR and Turbo emitter has been used with discharge of 4 L.h-1 which gave 94.68, 91.74 and 90%. Likewise, the most acceptable variety discharge ratio was observed when the same prior pipe and emitters were used with discharge of 4 L.h-1 by giving 7.23, 11.90 and 12.19 %.
Multivariate Models for Predicting the Maximal Diameter of the Wetted Area under Surface Drip Irrigation System
