| 1. |
- Aboulila, Tarek Selim, et al.
(författare)
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Assessment of inter-plant emitter distance and effects of irrigation water salinity on APRDI using Hydrus-2D
- 2011
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Ingår i: European Journal of Scientific Research. - 1450-216X. ; 58, s. 266-277
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedModern irrigation techniques are becoming increasingly important in water-scarce countries. In this study, a two-dimensional water and solute transport model, Hydrus-2D, was used to assess the impact of inter-plant emitter distance (IPED) and irrigation water salinity on soil moisture and salinity distribution as well as on water balance components under alternate partial root-zone surface drip irrigation (APRDI) of tomato growing in loamy sand soil. Three IPED (20, 30, and 40 cm) and three irrigation water salinity levels (0, 1, and 2 dS/m) were used to execute different simulation scenarios. Simulation results indicated that the fluctuations in water content within the root zone were more pronounced in case of 20 cm IPED. The root water uptake increased as the IPED decreased. Using brackish irrigation water in APRDI caused significant augmentation in soil salinity in the top soil layer especially at the location of plant. The impact of irrigation water salinity on root water uptake increased as the IPED increased. As irrigation water salinity increased the root water uptake decreased. At plant location, soil salinity reached its highest values at the top soil layer in case of 30 and 40 cm IPED with brackish irrigation water. However, high soil salinity values were observed between the 40 and 65 cm depths in case of 20 cm IPED. Based on the results, it appears that APRDI with non-saline irrigation water is more effective with short IPED considering that approximately half of the root system was exposed to drying cycle. In addition, short IPED is recommended in APRDI when using brackish irrigation water especially for plants with shallow root system taking into account crop salinity tolerance.
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| 2. |
- Aboulila, Tarek Selim
(författare)
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Evaluation of Modern Irrigation Techniques with Brackish Water
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern irrigation techniques are becoming increasingly important in water-scarce countries especially in arid and semiarid regions. Higher crop production and better water use efficiency are usually achieved by drip irrigation as compared to other irrigation methods. Furthermore, by using drip irrigation simultaneously with brackish irrigation water, some of the water stress due to shortage of fresh water resources can be managed. The objective of the current study was to investigate the influence of geometric design, soil type, irrigation regime and amount, and salinity of irrigation water on soil water and salinity distribution as well as irrigation efficiency using drip irrigation techniques in Egypt and Tunisia. Field and laboratory experiments as well as numerical simulations were used to achieve these objectives. Two field experiments were conducted at two different sites and soil types in Tunisia. The first experiment was conducted to explore the effect of different drip irrigation treatment (i.e., surface drip irrigation with and without plastic mulch and subsurface drip irrigation) and regime (i.e., daily and bi-weekly) on soil water and salinity distribution as well as contaminant transport for sandy loam soil. The second experiment was carried out to investigate the mobility of different tracers (bromide and dye) under surface drip irrigation in loamy sand soil. Lab experiments using soil samples collected in Egypt and Tunisia were made to estimate soil hydraulic properties, soil texture, and soil moisture content. Numerical simulations for surface and subsurface drip irrigation and alternate partial root-zone surface and subsurface drip irrigation with brackish irrigation water were executed to investigate the effect of geometric design, irrigation regime and amount, and salinity of irrigation water on soil water and salinity distribution as well as irrigation efficiency for different soil types in El-Salam Canal project region, Egypt. Field experiments showed that maximum dye penetration depth during daily and bi-weekly irrigation occurred for subsurface drip irrigation. Also, during the bi-weekly irrigation, dye depth was not only larger but also occupied a larger soil volume than for the daily irrigation. Thus, bi-weekly irrigation increases the risk for groundwater contamination. Also, higher soil moisture content within the flow domain occurred with mulching treatment and daily irrigation. Simulations displayed a very close agreement with observed soil wetting. Multiple tracer experiments revealed that the bromide moved faster than dye. Therefore, fertilizers transport deeper than organic pollutants under surface drip irrigation in initially dry loamy sand soil. Numerical simulations verified this. On the other hand, numerical simulations for surface drip irrigation in El-Salam Canal cultivate land showed that soil hydraulic properties govern the shape of the wetted zone. The wetted depth was larger in sand while the wetted radius was lower as compared to loamy sand and sandy loam. Simulation results for subsurface drip irrigation (SDI) showed that deeper emitter depth increases the potential groundwater contamination risk and fertilizer leaching especially in sandy soil and shallow rooted plants. Also, it is preferable to control the wetted volume of any soil type by regulating the amount of irrigation water according to soil hydraulic properties. Simulation results also revealed that higher moisture content values within the flow domain and higher root water uptake rates occurred in case of short inter-plant emitter distances (IPED) under alternate partial root-zone surface and subsurface drip irrigation (APRDI and APRSDI, respectively). Therefore, Short IPED is preferable especially for root systems with limited lateral extension. Salinity results showed that as the salinity of irrigation water increased, the salinity levels at the soil surface at the location of the plant trunk under APRSDI increased. Therefore, APRSDI is more suitable with non-saline irrigation water, especially for shallow rooted plants. However, in case of using brackish irrigation water, short IPED and shallow emitter depth are recommended for reducing soil salinity below the plant trunk.
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| 3. |
- Aboulila, Tarek Selim, et al.
(författare)
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Field experiment and numerical simulation of point source irrigation with multiple tracers.
- 2013
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Ingår i: International Journal of Sustainable Water and Environmental Systems. - 1923-7545.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, three plots in sandy soil in northern Tunisia were irrigated by a single irrigation dripper with a solution containing dye and bromide for three successive hours. Fifteen hours after ceasing of infiltration, horizontal 5 cm trenches were dug. Dye pattern, bromide concentration, and water content were recorded. Indication of preferential flow due to water repellency of initial dry soil was found during the early stages of infiltration. However no deep preferential flow occurred. This enables the use of drip irrigation to improve the sustainability of irrigation systems. Numerical simulation using Hydrus-2D was conducted for the field experiment. It was found that in both field experiments and numerical simulation the mobility of the bromide is different from the mobility of dye; the dye was retarded approximately twice by volume compared to bromide. The simulation results support the use of Hydrus-2D as a roughly, rapid and labor saving tool for investigation tracers’ mobility in sandy soil under point source irrigation.
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| 4. |
- Aboulila, Tarek Selim, et al.
(författare)
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Influence of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water on soil moisture and salinity distribution
- 2012
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Ingår i: Agricultural Water Management. - : Elsevier BV. - 1873-2283 .- 0378-3774. ; 103, s. 182-190
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Tidskriftsartikel (refereegranskat)abstract
- In alternate partial root-zone irrigation (APRI) a significant amount of irrigation water can be saved without considerable yield reduction. In this paper, Hydrus-2D/3D was used to investigate the impact of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water for growing tomato on soil moisture and salinity distribution. Three inter-plant emitter distances (IPED; 20, 30, and 40 cm), two emitter depths (10 and 20 cm), and three irrigation water salinity levels (0, 1, and 2 dS m-1) were used to implement the proposed simulation scenarios in loamy sand soil during a 40-day simulation period. The simulation results showed that higher soil moisture content was found beneath the plant trunk in case of 20 cm (short IPED) and near the domain border in case of 30 and 40 cm IPED. Short IPED guarantees more water in the maximum root density zone. A deeper wetting front occurred for deep emitter depth, while the wetting front reached the soil surface for shallow emitter depth. Salinity results revealed that as irrigation water salinity increased, the salinity in the top soil increased. In addition, the salinity at the soil surface increased as IPED and emitter depth increased. Higher root water uptake rates were recorded in the case of 20 cm IPED while the emitter depth did not show any considerable effect on root water uptake rates. Moreover, the applied irrigation water was fully consumed by the plant in case of short IPED. Emitter depth and salinity of irrigation water had negligible effect on amount of irrigation water extracted by plant roots and percolated amount below the bottom boundary of the flow domain. Overall, short IPED is recommended in APRSDI with or without brackish irrigation water regardless of the emitter depth.
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| 5. |
- Aboulila, Tarek Selim, et al.
(författare)
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Numerical evaluation of subsurface trickle irrigation with brackish water
- 2013
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Ingår i: Irrigation Science. - : Springer Science and Business Media LLC. - 0342-7188 .- 1432-1319. ; 31:5, s. 1125-1137
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Tidskriftsartikel (refereegranskat)abstract
- In this study, an assessment for a proposed irrigation system in the El-Salam Canal cultivated land, Egypt, was conducted. A numerical model (HYDRUS-2D/3D) was applied to investigate the effect of irrigation amount, frequency, and emitter depth on the wetted soil volume, soil salinity levels, and deep percolation under subsurface trickle irrigation (SDI) of tomato growing with brackish irrigation water in three different soil types. The simulations indicated that lower irrigation frequency increased the wetted soil volume without significant increase in water percolate below the plant roots. Deep percolation decreased as the amount of irrigation water and emitter depth decreased. With the same amount of irrigation water, the volume of leached soil was larger at lower irrigation frequency. The salinity of irrigation water under SDI with shallow emitter depth did not show any significant effect on increasing the soil salinity above tomato crop salt tolerance. Based on the results, it appears that the use of SDI with brackish irrigation water is an effective method for growing tomato crop in El-Salam Canal cultivated land especially with shallow emitter depth.
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| 6. |
- Aboulila, Tarek Selim, et al.
(författare)
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Simulation of soil water and salinity distribution under surface drip irrigation
- 2013
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Ingår i: Irrigation and Drainage. - : Wiley. - 1531-0361 .- 1531-0353. ; 62:3, s. 352-362
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Tidskriftsartikel (refereegranskat)abstract
- Higher crop production and higher water use efficiency are usually achieved simultaneously with surface drip irrigation compared to other surface irrigation methods. With increasing competition for fresh water nowadays, there is also a need for greater use of brackish water in agriculture. Effects of soil hydraulic properties, initial soil moisture content ( ), and the irrigation regime on soil water and salinity distribution under surface drip irrigation (DI) with brackish irrigation water for growing tomato in saline soil were investigated using HYDRUS-2D/3D model. Simulation scenarios were conducted including three soil types (sand, loamy sand, and sandy loam), two irrigation regimes (daily and on alternate-day irrigation), and two values. Simulation results revealed that the effect of the irrigation regime on the wetting patterns differed according to the soil’s hydraulic properties while the effect of the initial soil moisture content vanished after a few days. Alternate-day regime is suitable for fine-texture soil. Soil salinity patterns showed that the irrigation regime and value did not show any significant effect on soil salinity distribution under drip irrigation with brackish water. Higher soil salinity values occurred along the soil surface by the end of the simulation period. These higher values were closer to the emitter in sand as compared to loamy sand and sandy loam. Water balance calculations showed that as the initial soil moisture content increased, the free drainage component increased. However, the irrigation regime and initial soil moisture content value did not affect the evaporation rate and root water uptake rate.
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| 7. |
- Aboulila, Tarek Selim, et al.
(författare)
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Soil water and salinity distribution under different treatments of drip irrigation.
- 2013
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Ingår i: Soil Science Society of America Journal. - : Wiley. - 0361-5995. ; 77:4, s. 1144-1156
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, field experiments and numerical simulations for different drip irrigation treatments in a sandy loam soil were conducted to investigate soil water and salinity distribution as well as dye infiltration patterns. Three treatments, surface drip irrigation without and with plastic mulch (T1 and T2, respectively); and subsurface drip irrigation (T3), were used. In addition, daily and bi-weekly irrigation regimes were considered during performing each treatment. After ceasing the designed irrigation schedule of each treatment, horizontal soil sections were dug with 10 cm intervals. Then, dye patterns were captured using a digital camera and soil water and pore water electric conductivity were measured by a WET-sensor. Experiments results revealed that maximum dye infiltration depth and maximum dye coverage volume occurred during the bi-weekly irrigation regime and in T3. Daily irrigation regime kept the top soil layer moist with adequate amount of soil water as compared to bi-weekly regime. Moreover, T2 provided higher soil water content within the soil domain as compared to other treatments. The simulation results also demonstrated that model prediction for soil moisture distribution within the flow domain was excellent. Furthermore, T2 and daily irrigation showed lower salinity levels in the flow domain as compared to other irrigation treatments and regimes. In sum, mulching treatment with daily irrigation regime is recommended for arid areas over other drip irrigation treatments and regimes. In addition, HYDRUS-2D/3D can be used as a fast and cost effective assessment tool for water flow and salt movement for specific sites having similar soil conditions.
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| 8. |
- Aboulila, Tarek Selim, et al.
(författare)
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Spatial Analysis of Infiltration Experiment
- 2011
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Ingår i: Australian Journal of Basic and Applied Sciences. - 1991-8178. ; 5:7, s. 729-742
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Tidskriftsartikel (refereegranskat)abstract
- Developing correlations between various soil parameters are considered the major challenge to diminish time and cost associated with field measurements. Soil hydraulic and physical properties were extensively characterized using tension disc infiltrometer and soil sampling in a silty clay agricultural field in Kalaat El-Andalous, Tunisia. Tension disc infiltrometer experiments were conducted at 109 plots with two supply water potentials (-30,-60 mm) at each plot to determine the hydraulic conductivity, sorptivity, capillary length, and matric flux potential. In addition, soil samples were analyzed to determine the soil bulk density, and water content. From the statistical and spatial analysis for the different parameters, it was found that the soil hydraulic parameters had larger variability than bulk density. Sorptivity, capillary length, matric flux potential, and bulk density had lager variance with the distance between the plots. No correlation was found between bulk density and the soil hydraulic parameters, nor could the soil hydraulic parameters be correlated to each other.
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| 9. |
- Aljaradin, Mohammad, et al.
(författare)
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Evaluation of the Cover Effect in Mafraq Landfill –Jordan Using Hydrus-2d Simulation
- 2011
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Ingår i: IWWG. ; 13, s. 581-582
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Konferensbidrag (refereegranskat)abstract
- In this study, a two-dimensional numerical model for water flow and solute transport, Hydrus-2D, was used to investigate the impact of landfill cover thickness and the antecedent water content (Ө) of the soil beneath the landfill on the chloride percolation below the landfill. Series of simulation scenarios were performed using season varying climatic data during a 30-year period including two varying factors; thickness of landfill cover (0, 50, 100 cm) and the antecedent soil water content (0.12 and 0.20 m3m-3). The simulation results showed that maximum chloride concentration for different scenarios at all location within soil profile during the entire simulation period was less than the chloride concentration in the MSW leachate. In addition, as the landfill cover increased the concentration of chloride at a certain location decreased. Meanwhile, the time required to reach this location increased. The simulation results showed also that the impact of antecedent soil water content on chloride concentration reduction increase as the cover thickness increased. Based on the result, it was recommended to use a landfill cover to reduce the chloride concentration. Cover thickness of 50 cm is suitable in case of low antecedent soil water content.
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| 10. |
- Aljaradin, Mohammad, et al.
(författare)
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Evaluation of using grey water as an alternative irrigation source in Jordan
- 2011
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Ingår i: Vatten: tidskrift för vattenvård /Journal of Water Management and research. - 0042-2886. ; 67:2, s. 119-122
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Tidskriftsartikel (refereegranskat)abstract
- One option for coping with wasteful uses of fresh water in landscape irrigation is to use the treated greywater(GW). In the present study, an evaluation of a simple treatment system for reusing GW to irrigate green areas,trees, and ornamentals all over the campus in Tafila Technical University (TTU), Jordan, is presented. After 12 months of using the treatment system, the necessity for using fresh water as irrigation source was reduced. Meanwhile, the area of tree covered land increased from 2.3 ha to 8.4 ha and a 0.5 ha grass areas were introduced in the campus area. In conclusion, the use of a GW as alternative irrigation source is considered an effective method for saving fresh water and increasing green area at the campus.
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