More efficient water application is generally achieved when the design parameters match actual field conditions. On four sites, Kostiakov infiltration functions were derived from cylinder and blocked furrow infiltrometers and SCS (Soil Conservation Service) intake families according to soil type. An infiltration function was also developed using a hydrodynamic computer model to adjust equation parameters to fit field data. Computer simulations of level furrow irrigation, using each Kostiakov infiltration function, were compared to actual field data. Excluding those functions fit to the field data, Kostiakov infiltration functions obtained from blocked furrow infiltrometers generally provided the most consistent input for level furrow irrigation design and evaluation.

Field data were taken on furrow irrigations and compared with a hydrodynamic model (SRFR) which was used to predict irrigation performance. The field data were the furrow shape and slope, the infiltration characteristics of the furrow, the initial and final moisture content of the furrow, the rate and time of inflow, and the advance and recession trajectories. The hydrodynamic model predicted well the advance trajectories. It predicted recession trajectories which coincided with those of the field measurements for the upper end of the furrow but varied from the field measurements for the lower end. On the average, the uniformities calculated from observed data were higher than those predicted by the model. On the average, irrigation efficiencies calculated from field measurements were higher than those calculated with the model. Storage efficiencies for the observed data were all 100 percent because all irrigations completely met the requirement.

The comparative effectiveness of 7 different combinations of cooling techniques were tested in the summer of 1986 of Tucson, Arizona. Cooling techniques include premilking holding pen fanned-sprinkling, evaporative cooled milking parlors, exit water spray, as well as shade access in postmilking area. Ten Holstein cows were selected by different hair color predominately. Mean body temperature drops due to 7 different combinations of cooling techniques are presented. Twenty one planned comparisons between any 2 of the 7 different combinations are made. Sixteen comparisons showed significant (0.05) differences. Hair colors are of null effects on either body temperature drops or the stressed body temperatures. Body temperature patterns of the 7 different combinations during the milking time are graphically presented.

The effort to improve furrow irrigation design and management by use of mathematical models is hampered by the difficulty of obtaining infiltration parameters that adequately describe the infiltration process in furrows. This difficulty is related to the effect on infiltration of the variability of wetted width of a furrow with depth. Detailed field measurements of twelve furrow irrigations were used to develop infiltration parameters based on three different assumptions regarding the variation of wetted width with depth. These infiltration parameters were used as input into a mathematical model of furrow irrigation, SRFR. Comparison of measured advance times, water surface elevations and volume of water infiltrated with these values computed by SRFR indicates that SRFR gives consistent results based on the input parameters.

Water conservation in metropolitan areas of Arizona is critical if limited water resources are to meet current and future demands. Timer controlled landscape irrigation systems contribute to a large portion of municipal water use, and there is currently a great potential for water savings when deficit irrigation is practiced. Such systems tend to forfeit deficit irrigation by overwatering vegetation; however, deficit irrigation may be improved if the number of irrigation cycles are reduced based on sensing soil water in the plant root zone. A patent pending electronic circuit, called the overwatering controller, has been developed and tested for this purpose. Test results show the overwatering controller has great potential as a water conservation and deficit irrigation management tool.

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Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3629. Adviser: Kent D. Rausch. Includes bibliographical references (leaves 131-143) Available on microfilm from Pro Quest Information and Learning.