Results 261 to 270 of about 198,007 (304)

Variable Rate Precision Irrigation Technology for Deficit Irrigation of Processing Tomato

Irrigation and Drainage, 2018
AbstractCentre pivot machines, with a variable rate irrigation (VRI) package that provides individual sprinkler control systems (VRI iS), are not common. This research focuses on how uniform the water distribution is under VRI control, and on the size of over‐ and under‐irrigated areas and volumes.
Sándor Takács, Tibor Bíró, Lajos Helyes, Zoltán Pék   +3 more
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The Variable Rate Irrigation Management Challenge

2018
The potential for variable rate irrigation (VRI) is an approach to making better use of scarce water. Intuitively it makes sense to apply irrigation water when and where it will provide the most benefit, but implementing that simple insight is complicated because water control is costly.
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Variable Rate Irrigation 2010 Field Results

2011 Louisville, Kentucky, August 7 - August 10, 2011, 2011
Historically, the center pivot has been used by a farmer/operator to apply a selected depth of water uniformly across the entire field. Changes in technology have occurred that give growers the ability to apply differing amounts of water and products carried in the water to different zones along the pivot and sectors around the field (Perry 2005). This
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Key Performance Indicators for Variable Rate Irrigation Implementation on Variable Soils

2009 Reno, Nevada, June 21 - June 24, 2009, 2009
Decision support tools for precise irrigation scheduling are required to improve the efficiency of irrigation water use globally. This paper presents a method for mapping soil variability and relating it to soil hydraulic properties so that soil management zones for variable rate irrigation can be defined.
null C B Hedley, null I J Yule, null M P Tuohy, null I Vogeler   +3 more
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Analysis of basin irrigation performance with variable inflow rate

Agricultural Water Management, 1982
Abstract Basin irrigation systems were designed for a constant flow rate. The operation of the designed system was simulated using the zero-inertia model of surface irrigation. The performance of the system was obtained for modified design flow rates. Three patterns of flow variation — sinusoidal, initially low then high, and initially high then low —
J.Mohan Reddy, Wayne Clyma
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Performance Evaluation of Constant Versus Variable Rate Irrigation

Irrigation and Drainage, 2017
AbstractVariable rate irrigation (VRI) can increase water use efficiency and productivity by applying water based on site‐specific needs. In this study, the performance of a five‐span centre‐pivot irrigation system (CPIS) retrofitted with a commercial variable‐rate irrigation package was evaluated at constant and variable application depths at the ...
Aghil Yari, Chandra A. Madramootoo, Shelley A. Woods, Viacheslav I. Adamchuk   +3 more
openaire   +1 more source

Hydraulic performance characterisation of variable rate irrigation technology

2021
Variable-rate irrigation (VRI) technology for centre pivots and lateral moves has been commercially available for over three decades, but its uptake has been limited, with growers citing additional capital and operating costs, the detrimental impact on hydraulic and irrigation performance, as key issues.
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Strategy of Energy-saving for Variable-Rate Irrigation Sprinkler

2009 International Conference on Engineering Computation, 2009
The energy requirement for variable-rate irrigation sprinkler was analyzed. Boundary equations for triangular irrigation were set up. The relationships between irrigated angle, flow-rate and wetted diameter were included. Based on them, the relationship between flow-rate and variable pressure head for variable-rate irrigation system was obtained ...
Xingye Zhu, Shouqi Yuan, Junping Liu, Yin Luo   +3 more
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Effects of Variable-Rate Sprinkler Cycling on Irrigation Uniformity

2004, Ottawa, Canada August 1 - 4, 2004, 2004
Field studies with a center pivot (CP) and lateral-move (LM) irrigation systems were conducted to evaluate whether cycling of sprinklers ON and OFF to achieve variable application rates affects the overall application uniformity of an irrigation system. For the CP tests, collector test results showed CUC and DUlq values were 89 or greater with a slight
null Calvin D. Perry, null Michael D. Dukes, null Kerry A. Harrison   +2 more
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Variable-Rate Contour-Controlled Sprinklers for Precision Irrigation

2007 Minneapolis, Minnesota, June 17-20, 2007, 2007
The theoretical relationship between several hydraulic performance parameters of variable-rate contour-controlled sprinklers for high uniformity precision irrigation was researched. The operational equation that describes the internal connection of flow rate, rotating speed and throw distance of the variable-rate contour-controlled sprinkler was ...
null Han Wenting, null Fen Hao, null Wu Pute, null Yang Qing   +3 more
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