m n; b gh; b b
Abstract
Aloe Vera (Aloe Vera L.) is a medicinal plant adaptable to arid and warm climates as well as water limited conditions and can be introduced in cropping pattern of southern region of Iran. A field experiment was carried out during two years (2010-2011) in Bushehr, Iran, to investigate the effects of irrigation ...
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Aloe Vera (Aloe Vera L.) is a medicinal plant adaptable to arid and warm climates as well as water limited conditions and can be introduced in cropping pattern of southern region of Iran. A field experiment was carried out during two years (2010-2011) in Bushehr, Iran, to investigate the effects of irrigation interval and amount of irrigation water on yield and water use efficiency (WUE) of Aloe Vera. The treatments were arranged in a split plot design based on randomized complete blocks with three replications. Three irrigation intervals including 2, 4 and 6 days were allocated to the main plots. Also, 4 irrigation amounts, calculated based on four coefficients of class A pan i.e. 0.2, 0.4, 0.6, and 0.8 were allocated to the subplots. The results showed that increasing irrigation interval from 2 to 6 days had no significant effects on yield and WUE of Aloe Vera. The least yield, number of leaves per plant, height of bosk was related to the coefficient of 0.2, and there were no significant difference between coefficients 0.6 and 0.8. Also, by decreasing irrigation amounts, WUE increased significantly. The least WUE related to coefficient 0.8, while the maximum belonged to coefficient 0.2. Generally, to achieve the maximum yield (5.7 kg/plant) and WUE (15.5 g/lit), respectively, the coefficients 0.6 (equivalent to 656 mm water for the whole growing season) and 0.2 (equivalent to 219 mm water/season), and for the ease of management, irrigation interval of 6 days are recommended.
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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.
Sonia Zebardast; Hasan Tabatabi; Behzad Ghorbani
Abstract
Furrow irrigation is one of the common surface irrigation methods whose hydraulic behavior is under the influence of the inflow hydrograph. Accurate prediction of the advance phase is very important for design, management, and evaluation of this kind of surface irrigation system. In this study, the advance ...
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Furrow irrigation is one of the common surface irrigation methods whose hydraulic behavior is under the influence of the inflow hydrograph. Accurate prediction of the advance phase is very important for design, management, and evaluation of this kind of surface irrigation system. In this study, the advance phase was simulated for six different hydrograph conditions of continuous and cutback inflows to furrow by using surface irrigation mathematical models. Field experiments were performed in Aboureihan campus, located in the southeast of Tehran province. The field data collected included inflow and outflow hydrographs, advance and recession data, cross sectional area and geometry of furrow, field slope, and infiltrated water depth along the furrows. The results showed that the least value of root mean square error(RMSE) (with an average of 6.32) and the highest value of the model efficiency factor (average 0.95) were related to the cutback hydrograph whose flow was reduced to 0.75 of the initial inflow after 60% of the cutoff time. The highest value of the RMSE (with an average of 12.30) and the least value of the model efficiency factor (with an average of 0.83) belonged to the continuous hydrograph whose discharge was reduced to 0.25 of the total discharge and irrigation continued for the entire time of irrigation. The results also showed that in cutback inflows section, the hydrodynamic, zero-inertia, and kinematic wave models were not applicable for reduction of flow in any lengths or any times. The selection of mathematical model for simulation of the advance of flow in the furrow depends on the amount of inflow and cut off time.