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1
Martin, E. C., R. Wegge, and M. Sheedy. "Effects of High Frequency Irrigation on Irrigation Uniformity II." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/197490.
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Another year of data was collected to determine the effects of high frequency irrigation on irrigation uniformity in cotton production. A field located at the Marana Agricultural Center was split into two treatments. Treatment one was irrigated at approximately 35% depletion of available water in the plant rootzone. Treatment two was irrigated at approximately 65% depletion in the crop rootzone. Increased frequency of irrigation has shown improved yields in many cotton studies. However, these more frequent and lighter irrigation applications may cause problems with irrigation uniformity. Frequent rains during critical time periods made it difficult to ascertain the impact of the irrigation schedule on uniformity. However, the less frequent, heavier application rate did result in a more uniform irrigation.
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Kirnak, Halil. "Developing a Theoretical Basis for Demand Irrigation of Acer Rubrum." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392735898.
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Colaizzi, Paul Dominic. "Ground based remote sensing for irrigation management in precision agriculture." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/280497.
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The relationship between remotely sensed canopy temperature and soil moisture was studied. The objectives were to relate two remotely sensed canopy temperature-based indices, the Crop Water Stress Index (CWSI) and the Water Deficit Index (WDI), to soil moisture through the water stress coefficient, to estimate soil moisture depletion with the CWSI and the WDI, and to develop a remote sensing system aboard a linear move irrigation system that would provide field images of the WDI at one-meter spatial resolution. Studies were conducted in Maricopa, Arizona during the 1998 and 1999 seasons with cotton (Gossypium hirsutum, Delta Pine 90b). In 1998, the field was surface irrigated (low frequency irrigation), and the CWSI was calculated from canopy temperature measurements using stationary infrared thermometers. In 1999, the field was irrigated with a linear move system (high frequency irrigation), and the WDI was calculated using measurements made by the on board remote sensing system. Both the CWSI and the WDI were correlated to soil moisture through the water stress coefficient. Soil moisture depletion could be estimated using the CWSI under low frequency irrigation, but could not be estimated using the WDI under high frequency irrigation. These differences were attributed to the range of soil moisture resulting from infrequent surface irrigation vs. frequent irrigation using the linear move. High spatial resolution images of the WDI could nonetheless monitor water stress throughout the field from partial to full canopy cover, which demonstrated that ground-based remote sensing is feasible for irrigation management in precision agriculture. This application of remote sensing provides an opportunity to improve water use efficiency.
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Martin, E. C., G. Laine, and M. Sheedy. "Effects of High Frequency Irrigation on Irrigation Uniformity III." College of Agriculture, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/211315.
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Data was collected for a third season to determine the effects of high frequency irrigation on irrigation uniformity in cotton production. The past two seasons indicated that high frequency irrigation worked better on sandier soils than soils containing high clay contents. Although no significant differences were found, higher yields were obtained on a site with a relatively high sand content. A field located at the Maricopa Agricultural Center was split into two treatments. Treatment 1 was irrigated at approximately 35% depletion of available water in the plant rootzone. Treatment 2 was irrigated at approximately 50% depletion in the crop rootzone. Although the yield data from Treatment 1 was higher on the average, statistically, there was no difference between the two treatments.
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Kingdon, Lorraine B. "Double Duty for Irrigation Water." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/295634.
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Haberland, Julio Andres. "AgIIS, Agricultural Irrigation Imaging System, design and application." Diss., The University of Arizona, 2001. http://hdl.handle.net/10150/279836.
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Remote sensing is a tool that is increasingly used in agriculture for crop management purposes. A ground-based remote sensing data acquisition system was designed, constructed, and implemented to collect high spatial and temporal resolution data in irrigated agriculture. The system was composed of a rail that mounts on a linear move irrigation machine, and a small cart that runs back and forth on the rail. The cart was equipped with a sensors package that measured reflectance in four discrete wavelengths (550 nm, 660 nm, 720 nm, and 810 nm, all 10 nm bandwidth) and an infrared thermometer. A global positioning system and triggers on the rail indicated cart position. The data was postprocessed in order to generate vegetation maps, N and water status maps and other indices relevant for site-specific crop management. A geographic information system (GIS) was used to generate images of the field on any desired day. The system was named AgIIS (A̲gricultural I̲rrigation I̲maging S̲ystem). This ground based remote sensing acquisition system was developed at the Agricultural and Biosystems Engineering Department at the University of Arizona in conjunction with the U.S. Water Conservation Laboratory in Phoenix, as part of a cooperative study primarily funded by the Idaho National Environmental and Engineering Laboratory. A second phase of the study utilized data acquired with AgIIS during the 1999 cotton growing season to model petiole nitrate (PNO₃⁻) and total leaf N. A latin square experimental design with optimal and low water and optimal and low N was used to evaluate N status under water and no water stress conditions. Multivariable models were generated with neural networks (NN) and multilinear regression (MLR). Single variable models were generated from chlorophyll meter readings (SPAD) and from the Canopy Chlorophyll Content Index (CCCI). All models were evaluated against observed PNO₃⁻ and total leaf N levels. The NN models showed the highest correlation with PNO₃⁻ and total leaf N. AgIIS was a reliable and efficient data acquisition system for research and also showed potential for use in commercial farming systems.
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Crossley, Philip Lawrence. "Sub-irrigation and temperature amelioration in chinampa agriculture /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Gonz?alez, Rico Antonio. "Growth characteristics and water demand of three Quercus species under reduced irrigation using a computer-controlled irrigation system /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487843314696831.
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Yuan, Zhixu. "Flow variation in irrigation system components." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/289813.
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This research evaluated flow characteristics in three irrigation system components: Venturi injector, chemigation oil drop generator, and pressurized landscape bubbler. Foliar chemicals are often applied as oils through irrigation systems in order to prevent wash off from leaves. The system application uniformity and efficiency depends on oil drop size distribution. The primary parameters that influence oil drop size are water flow rate and eddy shear stress, interfacial tension and oil viscosity. In this laboratory experiment, the oil-based chemical drop diameter distributions were evaluated over a range of these physical parameters. Drop sizes were in the range of an equation used to predict drop size in turbulent flow; however, there was very little change in drop size with change in physical parameters. The injection flow rate for four chemicals (CAN17, UAN32, soybean oil, and OrchexRTM) and water was measured over a range of pressure differentials between the upstream and downstream side of the Venturi, and over a range of chemical temperatures. The injection flow rate for water, with low viscosity, did not change significantly with temperature. However, the injection rate for the four chemicals was correlated with temperature and viscosity. If the chemical tank temperature variation is 20°C during the day, then the injection flow rate variation would be in the range of 50% for soybean oil, 30% for OrchexRTM, 10% for UAN32, and 5% for CAN17. Five commercial bubbler with flow rate screw adjustments were evaluated: RainbirdRTM, ToroRTM, IrritrolRTM , HunterRTM, and LegoRTM. The coefficient of variation at full flow for the five brands ranged from 8.2% to 20.8%. Bubbler flow rates were measured at 140 and 210 kPa over a range of number of screw turns. Equations were developed for each bubbler based on the emitter flow equation, Q = KHx. Because K and x varied with number of screw turns, equations were developed for K and x for each bubbler based on regression of flow data. Correlation between calculated flow rates with the equations and measured flow rates was in the range of 80% to 90%.
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Knight, Susan M. "Irrigation Projects Could Mean Increased productivity." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/295685.
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Bergeron, Lyne. "Effet de la teneur en eau du sol sur le rendement et la qualité des fruits du bleuet nain /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1995. http://theses.uqac.ca.
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Scherer, T., D. Slack, J. Watson, and F. Fox. "Comparison of Three Irrigation Scheduling Methods and Evaluation of Irrigation Leaching Characteristics." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/204858.
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Three methods were used to schedule irrigations on replicated plots at the Maricopa Ag Center using DPL 90 cotton. The three methods were: a soil water balance model based on historic consumptive use curves, a soil water balance model based on the Modified Penman Equation and daily weather (AZMET), and infrared thermometry using the C.W.S.I. A potassium-bromide conservative tracer was applied at selected sites in the plots to evaluate leaching characteristics. The irrigation scheduling test was duplicated at the Safford Experiment Station and is presented in another report. Results from the 1988 data indicate that there was no significant difference in yield between the 3 methods. There was a significant difference in water applied; the historic consumptive-use curves was the lowest and the Penman equation method was the highest.
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Scherer, T., D. Slack, J. Watson, and F. Fox. "Comparison of Three Irrigation Scheduling Methods and Evaluation of Irrigation Leaching Characteristics." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/208305.
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Three methods were used to schedule irrigations during 1989 on replicated plots at the Maricopa Ag Center using DPL 90 cotton. This is a continuation of the research initiated in 1988 using the same field The three methods were; a soil water balance model based on historic consumptive use curves, a soil water balance model based on the Modified Penman Equation and daily weather (AZMET), and infrared thermometry using the C.W.S.I. A potassium- bromide conservative tracer was applied at selected sites in the plots to evaluate leaching characteristics. The irrigation scheduling test was again duplicated at the Safford Experiment Station and is presented in another report. Results from this years data indicate that there was no significant difference in yield among the three methods. However, as in 1988 there was a significant difference in water applied with historic consumptive use (ERIE) the lowest and the Penman equation method (CHECKBOOK) the highest.
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Scherer, Tom, Don Slack, Jack Watson, and Fred Fox. "Comparison of Three Irrigation Scheduling Methods and Evaluation of Irrigation Leaching Characteristics." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208344.
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Three methods were used to schedule irrigations during the 1990 growing season on replicated plots at the Maricopa Ag Center using DPL 90 cotton. This is the final report of the research initiated in 1988. The three methods were: a soil water balance model based on historic consumptive use curves (ERIE), a soil water balance model (AZSCHED) based on the Modified Penman Equation and daily weather (AZMET), and infrared thermometry using the Crop Water Stress Index (CWSI). A potassium- bromide conservative tracer was applied at selected sites in the plots to evaluate leaching characteristics. The irrigation scheduling test was again duplicated at the Safford Experiment Station and is presented in another report. Results from this years data indicate that there was no significant difference in yield between the 3 methods. Also, there was no significant difference in the amount of applied irrigation water. The AZSCHED and ERIE methods will be developed into Extension educational tools and released for use by growers.
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Abdulhussain, Mohamed Fidahussain 1964. "Gravity bubbler irrigation systems on steep slopes converted to bench terraces." Thesis, The University of Arizona, 1994. http://hdl.handle.net/10150/278410.
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Gravity bubbler irrigation is a new mode of irrigation activated by the existing pressure in conventional irrigation supply channels. In gravity flow systems on steep slopes, pressure increases in the downstream sections of the pipe and must be dissipated for uniform application. A design procedure for gravity bubbler irrigation systems on inclined steep slopes or converted to bench terrace systems is described in detail. The design is based on the use of orifices as energy dissipating devices. Laboratory tests were conducted to determine graphical relationships and coefficients for estimating the head loss for an orifice made from PVC. The head loss coefficient is a function of the orifice to pipe diameter ratio and can be expressed by an equation of the form Ko = abetab where a and b are constants determined from test data and beta is the ratio of diameters. A prototype gravity bubbler irrigation system was designed and installed.
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Suarez-Rey, Elisa Maria. "Subsurface drip irrigation of bermudagrass turf in Arizona: Benefits and limitations." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280210.
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Subsurface drip irrigation was compared to sprinkler irrigation on bermudagrass turf during three consecutive years using tertiary treated wastewater. Irrigation amount required by each treatment, visual appearance of the grass, shoot biomass production, and soil salinity were measured, and potential management problems were identified. The amount of irrigation water applied via subsurface irrigation was similar or higher than that applied via sprinkler irrigation for a turf of similar quality. Shoot biomass production did not differ between both irrigation methods when similar amounts of water were applied. Soil salinity, measured as electrical conductivity, was monitored at the beginning and end of each season. The changes in electrical conductivity at the end of every irrigation season did not negatively affect the appearance of the turf in any of the years. Emitter clogging by root intrusion was identified as a potential problem in the subsurface drip irrigation system. A series of greenhouse experiments were conducted to evaluate the effect of different herbicides and acids at several concentrations on root intrusion into subsurface drip emitters. The first greenhouse experiment was a study intended to identify chemical concentrations that could inhibit bermudagrass root growth in soil without negatively affecting the visual appearance of the grass. As a result, two herbicides, trifluralin and thiazopyr, and one acid, phosphoric acid, were selected for a second greenhouse experiment. The second greenhouse experiment focused on the effects of the two herbicides and the acid on root intrusion into subsurface drip emitters. Only the emitters treated with thiazopyr at the highest dose were completely clean, root-free emitters.
17
Farr, C. R. "Salinity Distribution Under Drip Irrigation." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204075.
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Roth, R. L., and B. R. Gardner. "Vegetable Research Under Sprinkler Irrigation." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/214110.
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Farr, C. R. "Planting Patterns Under Drip Irrigation." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219749.
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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.Planting pattern 2x1 skip row cotton outyielded variable row 32"x44" per gross field acre under drip irrigation with saline water. Skip row planting in deep water areas appears to be a feasible selection with high water cost, reduced tubing requirement, lowered land rentals and increased yield response.
20
Farr, C. R. "Comparison of Increased Irrigation Frequency." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204486.
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Msuya, Kassim Jumanne. "Applicability of drip irrigation for smallholder farmers: A case study of the horticultural industry in Tanzania." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1469152691.
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Clark, L. J., E. W. Carpenter, T. Scherer, D. Slack, and F. Fox. "Cotton Irrigation Scheduling, Safford Agricultural Center, 1988." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/204840.
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Cotton was grown using historical evapotranspiration data in the Erie method a checkbook method using real-time AZMET weather data, an infrared thermometer, and a faint manager to schedule irrigations. Yields of 4 bales per acre were recorded with no significant differences between the scheduling methods. Differences were seen in the plant growth and maturity. More refining will be done in subsequent investigations.
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Ottman, M. J., and B. R. Tickes. "Alfalfa Irrigation Termination, Yuma." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201407.
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Alfalfa irrigation is often withheld as a water conservation measure in Arizona. The objective of this research was to test the hypothesis that alfalfa yield and stand can be permanently damaged by withholding irrigation water. Irrigation was terminated during the summer (July through October) or winter (November through February) on a Superstition sand in Yuma. Summer irrigation termination reduced plant density from 4 to 1.5 plants per square foot and reduced hay yield from 0.76 to 0.27 tons per acre per cutting after irrigation was resumed. Winter irrigation termination had no residual effect on yield or plant density. Termination of alfalfa irrigation can permanently damage stands and reduce yield on sandy soil.
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Ottman, M. J., and R. L. Roth. "Alfalfa Irrigation Termination, Maricopa." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/201408.
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Alfalfa irrigation is often withheld as a water conservation measure in Arizona. The objective of this research was to test the hypothesis that alfalfa can be permanently damaged by withholding irrigation water. Irrigation was terminated during the summer (July or August through September) or summer through winter (July or August through mid -March) on a Casa Grande sandy loam at Maricopa. Irrigation termination at Maricopa was not detrimental to stand although hay yields were depressed from 1.47 to 1.28 tons per acre following the second cycle of summer irrigation termination and from 1.57 to 1.23 tons per acre per cutting following summer through winter irrigation termination. Alfalfa water use was reduced by irrigation termination even after irrigation was resumed. Total nonstructural carbohydrates in the roots were never less than the control during irrigation termination but decreased relative to normally irrigated alfalfa when irrigation resumed.
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Young, Lauren. "Irrigation Methods and Their Effects on Irrigation Water Efficiency in High Tunnels." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1609101/.
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Improving water efficiency is and will continue to be a top concern to meet the world food production demands for a growing population. By having a clear understanding of water efficiencies, communities will be able to address these concerns from an economic standpoint and use more productive methods to grow food and limit water consumption. This study examines the water efficiencies of three irrigation methods over a single growing season in southeastern Oklahoma. Two crops, tomatoes and cucumbers, were grown using drip irrigation, a self-wicking container, and a non-circulating hydroponics barrel. Results at the end of the season showed the drip irrigation method had the highest water efficiency in terms of yield of product over water applied for both crops. The drip irrigation method also had the lowest associated set up costs and second lowest time requirements after the hydroponics method. These results were found to be consistent with other studies that compared drip irrigation to other irrigation methods and showed drip to have the highest water efficiencies.
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Simons, Juli, and Juli Simons. "Self-Sterilizing Harvesting Materials and Irrigation Pipelines." Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/626710.
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Food production is a growing industry in Arizona making safe and sustainable practices for irrigating crops of the utmost importance. Harvesting materials such as knives, packing crates, plastic pallets and processing tables are constantly exposed to soil and other bacteria- laden environments presenting the risk for contamination. Irrigation pipelines are assembled using rubber gaskets to make a watertight seal. The gasket pipeline interface is a warm, moist environment that is subject to biofilm accumulation. Therefore, a long-term sanitization treatment of these materials would be greatly beneficial to the farms of Yuma, Arizona. Quaternary ammonium compounds and chlorine dioxide have proven to be sufficient household cleaning products. Our work examined the efficiency of these products as well as others in long- term sanitization of harvesting materials and irrigation systems. Treating materials with these compounds did not inhibit microbial growth or prevent biofilm accumulation in irrigation systems. The first study treated of harvesting materials (knives) with sanitization treatments. Samples were qualitatively analyzing the presence of Escherichia coli (E. coli) as an indicator bacteria and its ability to survive on the equipment after the equipment goes through three different treatments; water (as a control), QACs and bleach. The second study determined the efficacy of these treatments on packing materials such as wood, plastic and metal. Both studies found the treatment, given the contamination levels present in the study, was not an effective microbial control. The third study will quantified the presence of heterotrophic bacteria, E. coli and Salmonella as indicators of biofilm accumulation on irrigation pipeline gaskets. The same treatment methods were used for the gaskets that hold the irrigation pipelines together. The study determined that treating the gaskets did not inhibit the growth of biofilms and that pretreatment was not an effective microbial control. A field study determined that treatment residues did not
affect the growth of spinach. The present research provides preliminary data to assist in the development of future studies.
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Wissuwa, Matthias 1964. "Improvement of tolerance to summer irrigation termination in alfalfa." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282135.
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Withholding irrigation to alfalfa (Medicago sativa L.) during summer, a management strategy referred to as summer irrigation termination (SIT), has been suggested as a way to conserve water in desert environments. SIT may decrease productivity of alfalfa stands, although such negative effects may be reduced if cultivars with improved tolerance to SIT could be developed. This research was undertaken to determine how improved tolerance to SIT could be achieved through plant breeding. Single spaced plants of an extremely nondormant alfalfa population were grown in a field trial in Tucson, AZ and exposed to SIT in 1994 and 1995. These plants were used to identify traits associated with tolerance to SIT and represented parental material in a selection experiment. Direct selection for minimal reduction of forage yield following SIT was conducted under two stress intensities (lengths of SIT) and compared to indirect selection for characteristics potentially associated with dehydration avoidance. None of these selection criteria improved post-SIT forage yield relative to a random sample of plants from the parental population. This lack of response from selection was attributed to stress intensities that were not sufficiently high to fully expose genetic variation for yield following SIT. Physiological studies showed that high concentrations of total nonstructural carbohydrates (TNC) in crown tissue are positively associated with tolerance to SIT. Using TNC concentrations as an indirect selection criterion may therefore represent a more promising approach in improving tolerance to SIT than direct selection for post-SIT yield. Crown tissue was shown to die if the tissue moisture content fell below about 42%. This threshold value was used to predict whole-plant mortality of alfalfa grown in solid-seeded plots comparable to commercial fields. Crown samples were taken at five locations within the field along a soil gradient that caused whole-plant mortality to vary from 0.5 ± 0.5 to 48.7 ± 4.1%. Predicted values closely followed this change in observed mortality rates (r² = 0.97*) but tended to overestimate actual mortality on average by 4.2%. Alfalfa growers may be able to minimize mortality using this simple method to predict mortality during SIT and to reschedule irrigation accordingly.
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Kivumbi, Dorian. "Decision support system for improved irrigation water management." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301207.
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Jaria, Felix. "Irrigation scheduling strategies for tomato production in Southwestern Ontario." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116875.
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Precision irrigation scheduling is critical to improving irrigation efficiency. It is a combined technical and managerial tool that determines accurately when, how much and how often irrigation is applied to meet optimum crop response. This is particularly challenging in humid regions such as Southwestern Ontario, where soil moisture is often influenced by periodic rainfalls. The overarching goal of this three year research project was to investigate different irrigation scheduling strategies for tomato production in Leamingtion, Ontario. There were four specific objectives. The first sought to develop an optimum irrigation schedule for intensive cultivation of processing tomatoes by examining different irrigation trigger levels. Moisture triggers were expressed as a fraction of field capacity and soil tension, which are also related to soil available water content (AWC). Triggers with moisture depletion levels of ≤ 40 % (AWC) produced the higher yields. However, the best yields were obtained from the tension treatment with an upper and lower moisture threshold of -10 kPa and -30 kPa, which represented 20 to 24% depletion in AWC.The second objective sought to develop a robust protocol for implementing an irrigation scheduling. Three different types of soil moisture sensors were evaluated. The tension based senor emerged with the highest evaluation score. However, all three sensors could be used to effect irrigation scheduling. The sensor based irrigation data was subsequently compared with the Peman-Monteith model. It was found that the soil moisture treatments with a moisture depletion level of ≤ 40 % soil available water content (AWC) adequately met crop water requirements throughout the season.The third objective examined the spatio-temporal variability of soil moisture under drip irrigation in a controlled greenhouse environment. The study indicated that soil moisture content was not uniformly distributed prior to or after an irrigation event. For double row planting of tomatoes with a central drip line, a row spacing of 50 cm was adequate for planting of seedlings, due to the higher soil moisture contents within that zone. Further, due to the lack of uniform distribution of moisture in the soil profile, paired sensors (with one either side of the drip line) can provide a better estimate of soil moisture depletion for sensor based irrigation scheduling.The fourth objective investigated the nutrient dynamics along the soil profile over the growing season. Soil nutrients (P and N) were monitored at three different levels of the profile (0 to 30, 30 to 50 and 50 to 70 cm) and at the pre-planting, mid-season and end of season stages. Statistical significance in Olsen P and NO3-N was obtained both across the season and along the profile for each of the three years. The variability among treatments was not significant. The P and N concentrations at the 50 to 70 cm depths were found to be high, with the potential of being leached through the subsurface drainage system. A modification in the application of P and N can help reduce leaching of nutrients below the rooting zone. This would necessitate a split application of P and more frequent application of liquid N in smaller quantities.La planification précise de l'irrigation est critique à l'amélioration de son rendement. C'est un outil technique et de gestion qui permet d'évaluer avec précision la quantité et la fréquence d'application de l'irrigation afin de répondre à la demande pour une croissance optimale des cultures. Cette planification est particulièrement difficile dans les régions humides, comme celles du sud-ouest ontarien, où l'humidité des sols est influencée par des pluies périodiques. Le but fondamental de ce projet de recherche de trois ans était d'étudier les différentes stratégies de planification de l'irrigation pour la production de tomates à Leamington, Ontario. Il y a eu quatre objectifs spécifiques. Le premier a visé à développer une planification optimale de l'irrigation pour des conditions intensives de culture de la tomate destinée à la transformation en examinant différents facteurs déclencheurs pour l'irrigation. Le taux d'humidité, comme élément déclencheur, a été exprimé par une fraction de la capacité au champ et de la succion du sol, qui sont reliés à la réserve utile (RU) d'eau du sol. Le dispositif de déclenchement avec un appauvrissement en eau de ≤ 40% (RU) a produit les meilleurs rendements. Les meilleurs rendements ont été obtenus lors d'une tension entre les seuils critiques supérieur et inférieur d'humidité de -10 kPa et -30 kPa, ce qui représentait un appauvrissement de 20 à 24% de la RU. Le second objectif a visé le développement d'un protocole robuste pour la mise en opération d'une planification du calendrier d'irrigation. Trois différents types de capteurs de l'humidité du sol ont été évalués. Le capteur basé sur la mesure de succion est sorti gagnant avec la plus haute note d'évaluation. Cependant, les trois capteurs peuvent être utilisés avec succès pour le contrôle du calendrier d'irrigation. Les données obtenues lors de l'irrigation contrôlée par les capteurs ont été comparées avec le modèle de Peman-Monteith. Il a été démontré que les niveaux d'humidité du sol qui ont assuré un appauvrissement en eau de ≤ 40% de la réserve utile (RU) du sol en eau ont permis de remplir les besoins en eau des cultures tout au long de la saison. Le troisième objectif a examiné la variabilité spatio-temporelle de l'humidité du sol lors de l'irrigation au goutte-à-goutte dans une serre à environnement contrôlé. L'étude a montré que l'humidité du sol n'était pas distribuée uniformément et ce avant, comme après l'irrigation. Dans le cas des tomates de champ avec une ligne centrale de goutte-à-goutte, un espacement de rangée double de 50 cm fut adéquat pour le semis des jeunes pousses, grâce au plus haut taux d'humidité du sol dans cette zone. De plus, avec le manque d'uniformité de la distribution de l'humidité dans le sol, des capteurs jumelés (placés de chaque côté de la ligne goutte-à-goutte) pourraient donner une meilleure estimation de l'appauvrissement en eau du sol pour une meilleure programmation de l'irrigation contrôlée par capteur. Le quatrième objectif a étudié la cinétique des éléments nutritifs à travers le profil du sol tout au long de la saison de culture. Les éléments nutritifs du sol (P et N) ont été surveillés à différents niveaux du profil (0 à 30, 30 à 50 et 50 à 70 cm) et au moment précédant le semis, en mi-saison et en fin de saison. La signification statistique de P et N a été obtenue tout au long de la saison et selon le profil du sol et ce pour les trois années de l'étude. La variabilité entre les traitements n'a pas été significative. Les concentrations en P et N aux profondeurs de 50 et 70 cm se sont avérées élevées, avec un potentiel d'être emportées par le système de drainage souterrain. Une modification de l'application de P et N peut aider à réduire le lessivage du sol sous la zone racinaire.
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Farr, C. R. "Irrigation Termination Effect on Upland Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204076.
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Martin, E. C., S. Husman, R. Wegener, P. Brown, K. Johnson, and L. Schnakenberg. "Determining Soil Moisture for Irrigation Management." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210311.
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One key component in good irrigation management is the measurement of soil moisture to help determine when to irrigate. In this study, resistance blocks and tensiometers were compared to neutron probe readings to assess how well these devices followed soil moisture and whether the resistance blocks and /or tensiometers could be used to schedule irrigation in cotton production. The resistance blocks were placed at 6, 18, and 30 inches. Tensiometers were placed at 18 and 30 inches. The readings from the resistance blocks and tensiometers were compared to neutron probe readings taken at 6, 18, and 30 inches. The resistance blocks compared well with the neutron probe readings at the 6 inch and 30 inch depth. At the 18 inch depth, there was much scatter in the data. The tensiometers also showed good comparisons at 30 inches and poor comparisons at 18 inches.
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Gardner, B. R., and R. L. Roth. "Asparagus Production Under Sprinkler Irrigation." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/214133.
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Bai, Dan Molnar Joseph J. "Irrigation, income distribution, and industrialized agriculture in the Southeast United States." Auburn, Ala, 2008. http://hdl.handle.net/10415/1407.
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Nazzal, Yasser Kamal. "Systematic Framework for Evaluating Treated Wastewater Usage in Agricultural Irrigation." DigitalCommons@USU, 2005. https://digitalcommons.usu.edu/etd/6867.
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A general systematic framework with several sub-frameworks was developed to help managers make informed decisions related to the reuse of treated wastewater in agricultural irrigation. The framework involves the identification and evaluation of the short- and long-term effects of using treated wastewater with some common constituents of concern ( e.g. salts and some specific ions, nutrients, heavy metals, organic compounds, and microorganisms) on the environmental elements ( crop , soils, surface water, and groundwater), and on the public health. Local and/ or international standards, criteria, and guidelines related to agricultural reuse are applied to the evaluation of the effects. Based on the evaluation results, decisions are made and management alternatives are proposed. The management alternatives include improving the wastewater treatment level , blending treated wastewater with good-quality water, using an appropriate irrigation method, using different reuse schemes, and zero discharging from specific industries.
The framework demonstration includes the data input, information processing, output, evaluation, and decision-making phases. Data related to the plant-soil system (crop, soil, and any other assimilation pathway), and the behavior and fate of treated wastewater constituents are necessary for the identification of the effect on the environmental elements. Jordan was selected as a case study for the demonstration of the general systematic framework. Due to the lack of data related to the different constituents, some of the hazardous heavy metals were considered in the demonstration with the worst condition of accumulating the whole quantity of metals in the soil. The demonstration results showed that, at least for the coming 40 years Jordan can practice the reuse of the treated wastewater for agricultural irrigation without exceeding the maximum allowable limits in the agricultural soils based on the USEPA for biosolid application. With regard to blending and system efficiency, the demo result s also showed that they do not have an effect on the long-term accumulation of the hazardous metals in the soil.
The general systematic framework is a decision tool, which is able to answer questions related to water treatment level and type , when to blend with freshwater, the recommended blending ratio, the recommended irrigation method, selection of the optimum reuse scheme, as well as providing answers to questions related to industrial wastewater constituents.
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McGinley, Susan. "Safer Vegetables: Fewer Pathogens Survive Under Subsurface Drip Irrigation." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/622200.
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Salazar, Moreno Raquel. "Multiple criteria analysis of economic, environmental and water use problems in an irrigation district of Mexico." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/284229.
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The Alto Rio Lerma Irrigation District (ARLID), located in the state of Guanajuato in Mexico, is an agricultural area whose sustainability depends partially upon groundwater withdrawal for crop irrigation. Because of high pumping demands and current land-management practices, water levels in the regional groundwater aquifers have declined severely, resulting in aquifer overdraft. The potential adverse consequences of this overdraft cannot be overstated, as the long-term economic viability and environmental integrity of the region is threatened. In order to analyze this economic, environmental, and water use problems in this region, simulation of the agricultural system was performed and associated water use impacts quantified under different management scenarios. Linear programming identified the 12 optimal cropping patterns, and then multi-criteria decision-making methodologies were applied to rank and identify the best cropping pattern (satisficing solution). The GLEAMS model was used to simulate the amounts of water, nitrate, and pesticides in both runoff and percolation for each cropping pattern. In order to quantify the economic and environmental impacts of aquifer overdraft, two attributes were used; pumping costs and an aquifer exploitation coefficient. Three multiple criteria methods: Q-analysis, ELECTRE II, and the Range of Value Method, were evaluated and the latter method was selected to analyze the payoff matrix for the ARLID, where 12 alternatives, each with 13 attributes, were considered. The results show the best alternative for effectively balancing environmental with economic considerations was the farming practice, consisting of land leveling, growing vegetables such as red tomato, and controlled groundwater withdrawals to preserve aquifer sustainability. Low water availability does not necessarily reduce farmer's profits, if new water saving alternatives are applied, combined with more profitable crops. Given that ROV method only considers full compensation between objectives, this research contemplate an extension for the nonlinear case in order to assess the whole range of values of the objective function. The final findings suggest that the best methodology was to apply L1 in the lower levels and then L2 for the highest level in the hierarchy. In this manner, the partial compensation between objectives is considered and also the decrease in the uncertainty of alternatives selection.
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Kittock, David L., Roger A. Selley, and B. Brooks Taylor. "Comparison of Reduced Irrigation Strategies in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204073.
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Biggs, E. Niel, Lee Clark, and Laura Rose. "Scheduling Cotton Irrigation with the Neutron Probe." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219765.
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Rubeiz, I. G., N. F. Oebker, and J. L. Stroehlein. "Vegetable Crop Response to Subsurface Drip Irrigation." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/214134.
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Drip irrigation lines placed 15 cm (deep) and 5 cm (shallow) below soil surface were compared to furrow irrigation with zucchini squash as a summer crop and cabbage as a winter crop. Both crops were grown on the same drip lines in each treatment. Urea phosphate was injected in drip lines during growing season while the furrow-irrigated plots received preplant application of phosphorus. In squash, deep lines produced higher yields than did shallow. Deep-drip yields were comparable to those with furrow but used half the water and half the fertilizer. In cabbage, deep-drip yielded slightly higher than shallow-drip and furrow. In these studies, deep-drip was superior in applying water and fertilizer.
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Farr, Charles. "The Use of Drip Irrigation in Maricopa County." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/204544.
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Garrot, D. J. Jr, S. Stedman, and D. B. Benedict. "Tierra Prospera Farms CWSI Irrigation Scheduling Demonstration Test." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/204860.
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Harper, Fred. "Bell Pepper Row Cover and Drip Irrigation Test." College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/214257.
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Coons, J., and S. Mendlinger. "Tolerance of Lettuce to Salts in Irrigation Water." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/214483.
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Roupal, R. H., P. N. Wilson, and W. E. Hart. "The Eveonomics of Linear-Move Irrigation: Preliminary Results." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219724.
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Martin, E. C., E. J. Pegelow, and S. Stedman. "Comparison of Irrigation Scheduling Methods in Cotton Production." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210291.
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Three different irrigation scheduling techniques were compared in this study; aerial infrared, hand -held infrared, and neutron moisture gage measurements. There were four treatments with three replications of each. Treatment one was scheduled using aerial infrared imaging and analyzes performed by Agrometrics, Inc. Treatment two was scheduled using a hand -held infrared gun. Irrigations for this treatment were initiated at a crop water stress index value of 0.3. Treatments three and four were scheduled using neutron probe measurements. Treatment three was irrigated at 45% depletion of the available soil water. Treatment four was irrigated at 45% depletion of the available soil water until mid-bloom, when the strategy was changed to irrigate at 35% depletion. Yield results showed no significant difference between the treatments.
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Escurra, Jorge Jose. "Optimal Irrigation Management for Sloping Blocked-End Borders." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/214.
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A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m3/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m). To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase simulation which uses the four-point implicit solution method of the Saint-Venant equations, with an algorithm that changes the spatial and temporal weighting, in addition to an algorithm that handles the water depth profile at the blocked-end downstream boundary upon completion of the advance phase; (2) simultaneous advance-recession-phase calculations using a hybrid algorithm to solve the governing equations; and (3) recession-phase simulation using the four-point implicit method until (and if) divergence occurs, then the volume-method is applied to complete the simulation. The three parts also involve the use of computational grid management algorithms and a parabolic equation which defines the Chezy coefficient as a function of water depth. The model incorporates the downhill simplex optimization method to determine the recommended inflow rate and irrigation cutoff time, maximizing a composite irrigation efficiency (water requirement efficiency and application efficiency). Different optimum values of inflow rate and irrigation cutoff time for a range of longitudinal slopes, border lengths, and soil types were generated. Most of the optimum values are for relatively high inflow rate and rapid cutoff time. In addition, exponential relations were developed, based on the simulation results, to determine the best irrigation time for maximization of the composite irrigation efficiency for specified, non-optimal inflow rates. The exponential relations are particularly useful in practice when it is not feasible to use the optimum inflow rate due to constraints at the water source, or because of irrigation scheduling issues.
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Li, Qionfang. "An investigation of integrated management of irrigation systems for agriculture and aquaculture." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268373.
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Pratt, Tyler. "Urban Agriculture and Small Farm Irrigation: Case Studies from Cache Valley, Utah." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4995.
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The landscape of water in Utah is changing due to population growth, conversion of agricultural land to urban development, and increasing awareness of water scarcity. The Utah Division of Water Resources forecasts that the currently developed water supplies will not be enough to provide for Utah’s future population, and is pursuing conservation and new development to meet the state’s anticipated needs.
Along with the urban growth Utah is experiencing a growing urban and small farm agricultural sector, but knowledge of water use in these operations is limited. Further research in this area aids in understanding the impact of land use change on the state’s hydrology, aids the state water authorities in water use estimates, assists farmers in moving towards wiser water management, and helps Utah State University Extension better meet the needs of small irrigators.
My research creates a clearer picture of urban and small farm agricultural irrigation in Utah. For the 2015 growing season I performed irrigation evaluations for 24 urban and small farms in Cache Valley, and I explore the results from both case study and statistical perspectives. My results show a great degree of heterogeneity with irrigation efficiencies ranging from 6% to 100%. In general, small fields had greater irrigation depths than large fields, and surface irrigated fields applied higher depths than sprinkle and drip irrigated fields. Yet a big influence on efficiency was management, as fields relying on a set schedule had higher depths than fields that were irrigated inconsistently due to other factors. Therefore, water conservation programs focused on reducing irrigated area or providing technological alternatives may not result in true water savings if the effect of management is ignored. In particular, urban and small farmers need increased awareness of how management can result in savings of time and money, and improved knowledge of how to measure application rates, improve application uniformity, and scheduling techniques. With improvements in these areas, water management on urban and small farms can be improved, therein helping the urban and small farm irrigators themselves as well as the state in meeting its future water needs.
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Ismail, El-Sayed El-Shafei. "Computer simulation of crop response to irrigation accounting for salinity." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278807.
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Bush, David B., and William Edwin Martin. "Potential Costs and Benefits to Arizona Agriculture of the Central Arizona Project." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/310777.
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