Results 261 to 270 of about 140,482 (308)

Conserving Energy with Low-Pressure Center Pivots

Journal of the Irrigation and Drainage Division, 1980
Reduced-pressure, center-pivot irrigation systems offer the potential of applying irrigation water with significant energy savings. However, lowering the pressure of center-pivot systems may increase runoff and soil erosion, thereby reducing irrigation efficiency, decreasing uniformity of water application, and creating other operational problems.
James R. Gilley, Lloyd B. Mielke
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Friction Correction Factors for Center-Pivots

Journal of Irrigation and Drainage Engineering, 1999
Analytical equations for friction correction factors for center-pivot laterals without end guns are developed. This work illustrates a discrepancy when earlier equations are applied to center-pivots with small numbers of outlets. Earlier equations were also limited to center-pivots with constant outlet spacing.
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Performance of Low Pressure Center Pivot Systems

Transactions of the ASAE, 1984
ABSTRACT A computer simulation model was used to compare the effect of sprinkler spacing and terrain on the theoretical performance of six center pivots. Systems with impact sprinklers and low pressure fixed head spray sprinklers had the highest uniformities for constant spacings of 12 and 1.5 m, respectively.
null L. G. James, null S. K. Blair
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Center Pivot Design Capacities in Eastern Colorado

Journal of the Irrigation and Drainage Division, 1974
Design system capacities were developed for center pivot sprinklers irrigating corn in the Central Great Plains by simulating irrigations for 60 yr of climatic data collected at Akron, CO. The modified Penman equation for estimating potential ET for alfalfa as a reference crop was calibrated with lysimeter and meteorological data collected at the ...
Dale F. Heermann, Hollis H. Shull, Rome H. Mickelson   +2 more
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Power Sources for Center Pivot Irrigation

SAE Technical Paper Series, 1977
<div class="htmlview paragraph">The development of the center pivot irrigation system has allowed a level of process control not previously attainable in commercial agriculture. This form of irrigation now forms the dominant method for new lands going under irrigation.</div> <div class="htmlview paragraph">Consideration of alternative
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Droplet Kinetic Energy from Center-Pivot Sprinklers

5th National Decennial Irrigation Conference Proceedings, 5-8 December 2010, Phoenix Convention Center, Phoenix, Arizona USA, 2010
The kinetic energy of discrete water drops impacting a bare soil surface generally leads to a drastic reduction in water infiltration rate due to formation of a seal on the soil surface. Under center-pivot sprinkler irrigation, kinetic energy transferred to the soil prior to crop canopy development can have a substantial effect on seasonal runoff and ...
null Bradley A King, null David L Bjorneberg   +1 more
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Economic Design of Center-Pivot Sprinkler Laterals

Journal of Irrigation and Drainage Engineering, 2004
Center-pivot laterals are characterized by important friction loss, so therefore the energy consumption is also significant.
John D. Valiantzas, Nicholas Dercas
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Center-pivot uniformity analysis with variable container spacing

Irrigation Science, 2011
Evaluation procedures for determining water application uniformity under center-pivot sprinkler systems have been documented in various technical publications. The so-called “catch cans” (open containers) are placed along one or more radial legs from the center of the field to obtain sample water application measurements, from which standard ...
N. Marjang, G. P. Merkley, M. Shaban
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A Center Pivot Irrigation Simulator for Pesticide Applications

Transactions of the ASAE, 1982
ABSTRACT DROP size distributions & application rates were measured for a center pivot irrigation (CPI) system. A simulator employing eight stationary nozzles in an in-line configuration was designed to duplicate the CPI system performance. Tests showed for drop size distribu-tions and application rates, the simulator values (weighted average) were ...
null F. J. Pickle, null J. L. Chesness
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Demonstration of Intelligent Center Pivot Irrigation Technology

2014 ASABE Annual International Meeting, 2014
Abstract. Center pivot irrigation systems are predominantly designed to apply a relatively uniform amount of water to fields that are often inherently variable due to factors such as different soil types, topography, or multiple crops. This field variability can result in significantly waste of water and energy, runoff, chemical leaching, and ...
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