Naji al-Mefleh

Demand and competition for water has increased the desire for water conservation in the world. Drip irrigation, a relatively new and popular irrigation technology, has the potential to increase conservation of valuable water resources in irrigated agriculture. A field evaluation of a Green-Ampt based, drip irrigation theory (Chu, 1994) was conducted on a Renshaw sandy loam, a Brandt silty clay loam and an Estelline clay loam soil near Brookings, South Dakota. Field data consisting of wetted radii and maximum wetted depths under surface emitter discharges of 1, 2, 3, and 4 L/h were used to define soil wetted patterns. Undisturbed soil water samples were used to estimate saturated hydraulic conductivity, bulk density and initial water contents. The field and laboratory data sets in conjunction with Chu\u27s theory were used to obtain field estimates of two Green-Ampt soil parameters, the water content parameter (M) and the pressure potential parameter (H). Initial soil water contents were near field capacity values because of unusual rainfall prior to the tests. Thus, the field tests were conducted under soil water conditions wetter than normally associated with irrigation events. Water content parameter (M) values were not affected by emitter discharge but were influenced by soil type where the Brandt silty clay loam produced the highest value and the Renshaw sandy loam the lowest value. Likewise, pressure potential (H) values were not affected by emitter discharge but were affected by soil type where the Brandt silty clay loam and the Estelline clay loam values were similar to each other but were higher than the Renshaw sandy loam value. Soil type had minimal affect [sic] on the change of wetted radii versus time in the field. However, emitter discharge had a pronounced impact on wetted radii versus time relationships with the smallest radii associated with the smallest discharge at a given time after irrigation initiation. Ratios of maximum wetted depths and radii were not affected by emitter discharge but were affected by the soil type. The Renshaw sandy loam had the highest wetted depth to wetted radius ratio of the three soils while the Brandt silty clay loam had the lowest. A ratio of 1.38 for the Renshaw sandy loam soil indicated that the wetted depth was 1.38 times larger than the wetted radius. In contrast, a representative ratio of 0.88 for the Brandt silty clay loam indicated that the wetted depth is only 0.88 of the wetted radius value. Comparison of field and theoretical (Chu\u27 s model) results were interesting. Chu\u27 s model produced good agreement (5 % representative coefficient of variation, cv, value) between measured and estimated radii for the Estelline clay loam, fair agreement (10 % cv value) for the Renshaw sandy loam and poor agreement (15 % cv value) for the Brandt silty clay loam soil. The model produced estimated maximum wetted depths that were about 20% less than the field depths for the Renshaw sandy loam soil, about 5% less for the Estelline clay loam soil and about 25% more for the Brandt silty clay loam soil

This study investigated the influence of treated greywater on growth and protein content of multipurpose (forage and ornamental) transplants, Prosopis juliflora L., Prosopis tamarugo L., and Albizia lebbeck L. Transplants of tested species were irrigated with treated greywater, diluted greywater (grey + distilled water, 1:1/by volume), and distilled water (control) for seven months. Water quality analysis showed that the concentrations of nutrients and heavy metals found in the greywater were within the acceptable range compared with Jordan Institution for Standard and Metrology (JISM) and the World Health Organization (WHO) thresholds for safe use of greywater. Escherichia coli found in the greywater were lower compared to JISM and WHO guidelines for the safe use of greywater. Irrigation with treated greywater increased shoot fresh weight by 24–39% and dry weight by 34–40% compared to diluted greywater and control. No significant difference in crude protein was noticed between wate...

The evaluation of non-conventional water resources on seed germination and seedling growth performance at early growth stages is still in progress especially in forage crops. This study was designed to test the effect of four types of water qualities (treated wastewater (TWW), industrial water (IW), grey water (GW), and Distilled water (DW)) on germination and early seedling vigor of Leucaena leucocephala. The results showed that the germination was not significantly affected by the different water qualities. Seed germination reached maximum after 17, 14, 14, and 21 days under GW, IW, TWW, and DW treatments, respectively. The highest mean of shoot length was scored under the GW treatment. And, the highest mean of root length was scored under DW which was not significant from GW treatment. The means of shoot fresh was the highest under the TWW. The means of root fresh weight was not significantly different from each other's under different treatments. The growth performance was i...

Vetch is a forage crop that is widely grown in high rainfall areas in Jordan for forage production and grazing. Growing vetch species out of the season will need irrigation, which is very expensive. In here, we propose application of wastewater or olive mill wastewater as alternative to the fresh water. An experiment was carried out to evaluate the effect of diluting the industrial water (IND) with olive mill wastewater (OMWW) on the vetch germination (GR) and early seedling growth under controlled conditions. The water treatments consisted of T1 (pure IND100%), T2 (mix of IND75% + OMWW25%), T3 (IND50% + OMWW50%), T4 (IND25% + OMWW75%) and T5 (pure OMWW100%) and tap water (control). This experiment was designed in a CRD with three replications for each treatment. Several measurements on the morphological and biochemical analysis were taken during this study such as seed germination (GR), as well as the seedlings fresh weight of shoot (FWS), dry weight of shoot (DWS), fresh weight of...

A field study evaluating wetted radius (Wr), downward depth (Dd), and upward movement (Um) under different emitter discharges and lateral depths was conducted. Four emitter discharges (2, 4, 8, and 16 L/h) and four lateral depths (0, 10, 20, and 30 cm) were tested in a clay loam soil. Relationships were found between the emitter discharge and lateral depth versus Wr, Dd, and Um. Wetting area at the surface occurs under different emitter discharges and lateral depths except at 30 cm lateral depth. At lateral depth of 0 and 10 cm, Wr and emitter discharge were positively correlated. The Dd was not affected by emitter discharge except for laterals installed at 20 cm depth. At 30 cm lateral depth, the correlations between each of Wr, Um, and Dd with emitter discharge were poor. The ratios of Wr/Dd and Um/Dd, with respect to emitter position, were less than unity over different emitter discharges and lateral depths. These results shed some light on the design of subsurface drip irrigatio...

The evaluation of non-conventional water resources on seed germination and seedling growth performance at early growth stages is still in progress especially in forage crops. This study was designed to test the effect of four types of water qualities (treated wastewater (TWW), industrial water (IW), grey water (GW), and Distilled water (DW)) on germination and early seedling vigor of Leucaena leucocephala. The results showed that the germination was not significantly affected by the different water qualities. Seed germination reached maximum after 17, 14, 14, and 21 days under GW, IW, TWW, and DW treatments, respectively. The highest mean of shoot length was scored under the GW treatment. And, the highest mean of root length was scored under DW which was not significant from GW treatment. The means of shoot fresh was the highest under the TWW. The means of root fresh weight was not significantly different from each other's under different treatments. The growth performance was i...

This study aims to investigate existing water management problems and potential solutions in the Al-Mafraq Governorate of Jordan, and to examine public awareness of water demand management at the household level. A questionnaire survey captured residents' perceptions of water quantity and quality. Results showed that 71% of respondents find the water pumped from the public system to be insufficient, and 40.9% find that water laws and regulations are implemented ineffectively. The study also showed that 85% of respondents are dependent upon groundwater wells, and 42.5% of respondents have suffered water contamination. Water quality is degraded due to pollution caused by solid waste and liquids, and salinity is increased due to the over-pumping and depletion of groundwater resources. The study recommends that the government incentivize residents to harvest water to deal with water shortages, religious motivations be explored in water conservation efforts, and water authorities sho...

Water harvesting techniques have shown promising outcomes in mitigating risks, increasing yields and delivering positive influences on other ecosystems. A field study was conducted in Northern Jordan to assess the influence of combined in-situ water harvesting techniques, micro-catchment and mulching on soil moisture content, plant morphology, gas exchange [photosynthesis (Pn), transpiration (E), and stomatal conductance (gs)] and midday stem water potential (Ψsmd) of young pistachio (Pistacia vera cv. Ashori) trees. Four mulching treatments [straw, vertical gravel, horizontal gravel and control (no mulching)] and three micro-catchment areas (36, 64 and 100 m2) were used. Pistachio trees were grown under rainfed conditions for two growing seasons. Gravel mulching (vertical and horizontal) and 36 m2 micro-catchment had the highest percentage increase in plant height compared with other treatments. In addition, 36 m2 micro-catchment significantly increased gas exchange variables (Pn, ...

A field study was carried to determine the impact of the land application of polyacrylamide (PAM) on the runoff used for supplemental irrigation. Five treatments were investigated: PAM A-130, PAM A-836, PAM Aerotil, plastic mulch, and natural (no PAM no mulch). Runoff was collected in barrels placed at the downstream end of fifteen plots and then used for the irrigation of acacia trees planted in an experimental site in Jordan. The growth characteristics of the acacia were monitored over a two-year period from 2009 to 2010. The total runoff volumes were significantly different over PAM A-836, PAM Aerotil, and plastic mulch compared to the natural. The results showed that supplemental irrigation of acacia with water collected from PAM plots significantly increased the acacia height and number of leaves compared to the natural and rainfed treatments. The use of PAM-treated runoff also slightly increased the number of branches of the acacia, but the increase was only significant in the...

This study aims to investigate the influence of treated wastewater (TWW) on the hydraulic performance of drip irrigation emitters. A field experiment was conducted in order to test two types of online emitters, a low pressure (LP) and a standard pressure (SP), at different working pressures (0.25 bar, 0.50 bar, and 1.00 bar) using TWW. The emitters were initially evaluated in the laboratory and the field for the discharge exponent (X), discharge coefficient (Kd), average emitter discharge (Qavg), coefficient of variation (CV), distribution uniformity (DU), the mean discharge ratio (Dra), and the main degree of clogging (DC). The main effect of the emitters on the hydraulic parameters of irrigation performance was not significant, while the operational pressure and operational time of irrigation had a significant effect. For the LP emitter, the average emitter discharge was 7.6, 7.7, and 7.8 Lh−1 at 0.25, 0.50, and 1.00 bar, respectively. For the SP emitter, the average emitter disch...

This study aims to investigate existing water management problems and potential solutions in the Al-Mafraq Governorate of Jordan, and to examine public awareness of water demand management at the household level. A questionnaire survey captured residents' perceptions of water quantity and quality. Results showed that 71% of respondents find the water pumped from the public system to be insufficient, and 40.9% find that water laws and regulations are implemented ineffectively. The study also showed that 85% of respondents are dependent upon groundwater wells, and 42.5% of respondents have suffered water contamination. Water quality is degraded due to pollution caused by solid waste and liquids, and salinity is increased due to the over-pumping and depletion of groundwater resources. The study recommends that the government incentivize residents to harvest water to deal with water shortages, religious motivations be explored in water conservation efforts, and water authorities sho...

Impact of different irrigation levels on the melon fruit characteristics, total fruit yield and water use efficiency (WUE) was studied under field conditions in arid region. Two experiments with three treatment levels of actual evapotranspiration (AET) were tested. These treatments were: 0.50 AET (T1), 0.75 AET (T2) and 1.00 AET (T3). Irrigation levels had a significant effect on length, diameter, weight, Brix, flesh firmness, seeds, fertile seeds and sterile seeds of melon fruit (p<0.05). Increasing the irrigation levels increased the length, diameter, weight, Brix, flesh firmness, seeds, and fertile seeds of melon fruit. In Experiment 1, the means of total fruit yield were 19.3, 23.5, and 21.1 t ha -1 at 0.50 AET, 0.75 AET and 1.00 AET, respectively. In Experiment 2, the means of total fruit yield were 15.6, 19.2, and 21.7 t ha -1 at 0.50 AET, 0.75 AET, and 1.00 AET, respectively. The irrigation levels did not have significant effect on the WUE in Experiment 1 and vice versa in...

Experimental tests are carried out to evaluate the impact of treated wastewater (TWW) on the discharge of five different types of emitters which are commonly used. Two water qualities, fresh water (FW) and treated wastewater, and five types of emitters, GR, Nein (NE), Edin (ED), Corona (CO), and Rain Bird (RB) are tested. The values of chemical properties for FW show mostly low clogging potential on emitter performance. The clogging potential for TWW varied from low to medium. The exception was for pH where there was severe clogging potential for both water types. The performance of emitters was tested by measuring the emitter discharge and estimating the average emitter discharge (Qavg), coefficient of variation (CV), emission uniformity coefficient (EU), and Christiansen uniformity coefficient (CU). The average discharges for different types of emitters were analyzed and compared at P ≤ 0.05. The CO and RB emitter types did not show any signs of clogging whereas the GR, NE, and ED...

Water is considered an important factor in the arid and semi-arid areas because water shortage affects the agricultural production. The current study aimed to investigate the influence of water application level on the dry matter yield, water use efficiency (WUE), and plant water status in Leucaena leucocephala. The treatments consisted of five levels of water applications based on actual evapotranspiration (AET): 0.25, 0.50, 0.75, 1.00 and 1.25 AET respectively. The production was increased from 306.4, 676.3, 724.1, 838.5, to 1172.7 kg/ha as the water application levels increased. The estimated WUE was 2.32, 2.57, 1.83, 1.59 and 1.78 kg/ha/mm for 0.25, 0.50, 0.75, 1.00 and 1.25 AET, respectively. Increasing the water application level did not increase the WUE. Using the irrigation level at 0.50 AET can be used to irrigate Leucaena crop without leaving any significant change in dry matter yield compared with 0.75 and 1.00 AET, respectively. There was no significant effect of water a...

The impact of water quality-fresh water (FW), mixed water (MIX), and treated wastewater (TWW)–and number of harvests–three (H3), two (H2), and one (H1)–during the season on biomass yield and essential oil quantity and quality of lemon verbena(Aloysia triphylla) were studied. The production variables (fresh, air-dry, oven-dry weight, and dry matter percent) of lemon verbena biomass were affected by the harvesting

ABSTRACT A field study evaluating wetted radius (Wr), downward depth (Dd), and upward movement (Um) under different emitter discharges and lateral depths was conducted. Four emitter discharges (2, 4, 8, and 16 L/h) and four lateral depths (0, 10, 20, and 30 cm) were tested in a clay loam soil. Relationships were found between the emitter discharge and lateral depth versus Wr, Dd, and Um. Wetting area at the surface occurs under different emitter discharges and lateral depths except at 30 cm lateral depth. At lateral depth of 0 and 10 cm, Wr and emitter discharge were positively correlated. The Dd was not affected by emitter discharge except for laterals installed at 20 cm depth. At 30 cm lateral depth, the correlations between each of Wr, Um, and Dd with emitter discharge were poor. The ratios of Wr/Dd and Um/Dd, with respect to emitter position, were less than unity over different emitter discharges and lateral depths. These results shed some light on the design of subsurface drip irrigation scheme so that the spacing between emitters should be determined based on the lateral depths and discharge of emitters. Evaporation losses were negligible for the 30-cm-lateral depth since the upward moisture movement has not reached the soil surface area at all discharge rates tested in the study.