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Abstract
Emitter clogging is the main problem in the use of wastewaters in drip irrigation systems which reduces the emitter discharge, emission uniformity, irrigation efficiency and increases maintenance costs. Aquaculture effluents contain appropriate nutrients (nitrogen and phosphorus) that can be used by ...
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Emitter clogging is the main problem in the use of wastewaters in drip irrigation systems which reduces the emitter discharge, emission uniformity, irrigation efficiency and increases maintenance costs. Aquaculture effluents contain appropriate nutrients (nitrogen and phosphorus) that can be used by plants. Hence, the aim of this study was to evaluate the effects of aquaculture effluent on hydraulic performance of Netafim and Microflopper emitters with different discharges. For this purpose, two drip irrigation systems were established to use inflow water and wastewater of a fish farm in Kurdistan province. Also, adding a management treatment, the effect of drip irrigation laterals discharge at the end of each irrigation event was studied when using this type of waste. The relative discharge, emission uniformity, Christiansen Uniformity Coefficient, statistical uniformity and discharge reduction rate were used to compare the hydraulic performance of the emitters. The results showed that in both fresh water and wastewater cases, the hydraulic performance of Netafim 4 l/hr and Netafim 8 l/hr emitters were better than the Microflopper 4 l/hr, Microflopper 8 l/hr and Netafim 12 l/hr emitters, respectively. Also, Netafim 4 l/hr emitters had the least dependence and sensitivity to water quality and irrigation management compared to the other studied emitters. In addition, the use of management treatment, for lateral pipe flushout, has a great impact on improving the performance of Netafim 12 l/hr and Microflopper 8 l/hr emitters.
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Abstract
Distribution uniformity of water is one of the most important parameters for evaluation of irrigation systems. Numerous equations have been developed to calculate distribution uniformity coefficient in sprinkler irrigation systems. The provided equations do not necessarily yield the same results in calculation ...
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Distribution uniformity of water is one of the most important parameters for evaluation of irrigation systems. Numerous equations have been developed to calculate distribution uniformity coefficient in sprinkler irrigation systems. The provided equations do not necessarily yield the same results in calculation of uniformity coefficient for one specific farm in a particular condition. The aims of this study were the evaluation of various equations proposed by different researchers, investigation of the effects of different field conditions on the results, investigation of the existing relationships among outcomes of the equations, and feasibility of using these equations. For this purpose, distribution uniformity coefficients were calculated using the equations presented by Christiansen, Hawaiian Cane Society Specialists Hart and Reynolds, Wilcox and Swailes, Karmeli, Criddle et al, Benami and Hore, and Beale and Howell, for 10 sprinkler irrigation systems in Shahrekord fields. Data analysis was performed using Statistical Analysis System (SAS) Software in a randomized complete block design. The results indicated that there were significant differences (P< 0.05) between the aforesaid coefficients and some of these equations estimated a negative number or a number larger than 100% for coefficient of uniformity in some specific conditions of sprinkler irrigation. Furthermore, in all cases, beta distribution could estimate the water distribution uniformity coefficient (CU) better than the normal and uniform distributions. In all three beta, normal, and uniform distributions, minimum agreement between predicted and measured values was related to equations by Karmeli, Beall and Howell, and Benami and Hore; and the most agreement, particularly in the beta and normal distribution, was related to the Christiansen equation. The results conclusively indicated that a number of coefficients of uniformity such as Benami and Hore, Karmeli, and, to some extent, Beal and Howell coefficients are strongly dependent on specific field conditions and are not applicable under other field conditions.