Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />': ,,-' , <br />~~~~~9 <br />V'__JUJ <br /> <br />Sprinkler Systems - a variety of irrigation application equipment which <br />utilize spraying nozzles or devices to distribute water over the land.* <br /> <br />1. Center pivots - a line of pipe on wheels, usually elevated above <br />potential crop heights, with numerous sprinkler heads along the pipe. <br />The center pivot is fixed at one end (the pivot point) at the water <br />source (well or buried pipe riser), and rotates automatically <br />(electric or hydraulic driven wheels). The most typical center pivot <br />units are quarter-section systems which irrigate about 130 acres. <br />Various devices, end-guns, or other methods have been used to irri- <br />gate the dry corners of center pivot systems, but none have proven <br />very effective. Most center pivots operate at relatively high water <br />pressures (80-100 psi at the pivot) and distribute water in a normal <br />(upward and horizontal) direction with impact spray nozzles. More <br />recent improvements in center pivot designs include low-head (25-50 <br />psi) downward spraying nozzles that require less energy and give <br />improved application efficiencies. Center pivots are also being <br />adapted as modified trickle (non-spray) systems with flexible hoses <br />at each nozzle to place the water directly on the land surface. <br /> <br />2. Hand-move/drag/or tow systems - these are the more conventional <br />sprinkler systems, using portable aluminum pipe directly on the soil <br />surface, with sprinkler heads elevated to various heights by risers <br />at each nozzle spacing. Although the least expensive (equipment <br />costs) of all the systems, these are the most labor intensive and <br />frequently the least efficient (AE). <br /> <br />3. Side-rolls (Wheel-roll) - a system of irrigation pipe mounted on <br />wheels which moves straight across a field or a set, with water <br />source either from portable (or buried) pipe along one side of the <br />set, or from flexible pipe. Sprinkler heads are spaced along the <br />pipe such that a designed overlap is achieved for a good coefficient <br />of uniformity. <br /> <br />* See illustration in Figure 3, page 17. <br /> <br />xv <br />