- Author: Ben Faber
The Irrigation Training & Research Center (ITRC) of Cal Poly San Luis Obispo tested 28 different pressure-compensating models of microirrigation emitting devices from a total of nine manufacturers in order to compare independent laboratory testing with manufacturer specifications.
The test results indicate that:
The majority of ~0.5 gallon-per-hour emitters (drippers), regardless of manufacturer exhibited:
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Good uniformity of manufacturer
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Had excellent response to pressure variation
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Had consistent flow rates within the nominal operating pressure range
But that the percentage of well-performing products decreased as the designed flow rate increased. Many of the emitters designated as microsprinklers or sprayers, although pressure compensating did not compensate at the normal operating pressures. Often the pressure compensating feature did not start performing until much higher pressures were achieved. Often this occurred when clogging occurred and this clogging often occurred where the pressure diaphragm was located and was not performing. Sediment would get in back of the diaphragm. Effectively the emitters were not pressure compensating. The testing procedure of numerous medium and high flow models also found individual pieces were found to be defective. These faulty emitters had a measurable effect on the evaluation for those models.
Read more at: http://www.itrc.org/reports/pdf/emitters.pdf
- Author: Ben Faber
Sand media filters are commonly used in agricultural microirrigation systems. They have the advantages of simplicity and large capacities and are favored by many farmers and designers over other filtration hardware when there is a lot of organic matter in the water. The Irrigation Training and Research Center (ITRC) at Cal Poly San Luis looked at sand filters to see if it were possible to use lower-than-accepted backflush pressure and thereby reduce the total pressure required for irrigation systems. By lowering backflush pressure it would be possible to design a system that could run at an overall lower pressure and hence cost. The various components of microirrigation systems run at lower pressures than the backflush pressures recommended for most sand media filters.
The conclusions are:
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There are substantial pressure differences amongst different models and designs during backflush and filtration
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The main pressure loss is at the backflush valves
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If designed right large backflush flow rates can be accomplished at low backflush pressures (this is critical for proper detritus removal).
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There are substantial differences among underdrains of various models which affects pressure requirements
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No large intimal high pressure was necessary to break up the media bed, a common practice.
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Different underdrain designs create different patterns of cleaning the media.
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There were substantial differences among models in the amount of sand discharged from the system at backflow rate of 190 GPM. Sand discharge should actually be avoided since it's an indication of preferential flow and poor cleaning.
These are some new ideas, and even though they are meant to reduce pressure and energy use, they are also good management suggestions.
If this strikes your fancy, read more at http://www.itrc.org/reports/mediafilters.htm
- Author: Pamela Kan-Rice
The 2014 Experiment Station Section Excellence in Multistate Research Award presented by the Experiment Station Committee on Organization and Policy on Nov. 2 recognizes the universities' exceptional collaboration on a multistate research project.
Patrick Brown, professor in the Department of Plant Sciences at UC Davis, Jan Hopmans, professor in the Department of Land, Air and Water Resources at UC Davis, Larry Schwankl, UC Cooperative Extension specialist emeritus, and Ken Shackel, professor in the Department of Plant Sciences at UC Davis, are the UC researchers participating in the project “Microirrigation for Sustainable Water Use.”
"The Multistate Research Program is one of the best kept secrets of the land-grant university system, and this award recognizes outstanding interdependent efforts of researchers and extension specialists that have come together to tackle a priority issue that no one institution can address on their own,” said H. Michael Harrington, executive director of the Western Association of Agricultural Experiment Station Directors. “This microirrigation project was selected out of more than 300 multistate projects because, since 1972, the group has made major advances in sustainable agriculture and water conservation.”
Using more precise irrigation management, California growers have increased water use efficiency on processing tomatoes by 54 percent and on almonds by 33 percent since 1990.
Conventional irrigation systems that apply high volumes of water over wide areas can lose a lot of water through runoff, wind, or evaporation. As a result, conventional irrigation systems often over water or under water plants. Instead, microirrigation, or drip, systems use special timers, sensors, and a network of narrow tubes to deliver the right amount of water at the right time.
In the last five years, the group's research has led to new microirrigation equipment and tools that are easier to install, more durable, and more precise. These advances, along with engagement with farmers, have encouraged adoption of microirrigation systems, which has led to significant economic and environmental impacts.
“As director of USDA-NIFA, my goal is to ensure the science we invest in leads to solutions to today's most pressing challenges,” said Sonny Ramaswamy. “One of those challenges is finding ways to feed the growing population while minimally impacting the environment. A safe, reliable supply of water is inextricably linked to food security. The five-fold increase in irrigated acres that took place during the 20th century cannot be repeated in the 21st century — there isn't the space. Instead, we must increase efficiency of the irrigated farmland we have, and that is what this project is doing.”
In addition to UC, other participating land-grant institutions include Auburn University, University of Arizona, Colorado State University, University of Florida, University of Hawaii, University of Idaho, Iowa State University, Kansas State University, Mississippi State University, University of Nebraska, New Mexico State University, Cornell University, Oregon State University, University of Puerto Rico, Texas A&M AgriLife Research, University of the Virgin Islands, Washington State University, and University of Wyoming. The universities collaborated with the USDA's Natural Resources Conservation Service and Agricultural Research Service.
The award was presented by ESCOP chair Bob Shulstad and Ramaswamy at the Association of Public and Land-Grant Universities annual meeting in Orlando, Fla.
The project's name will be added to a plaque at the USDA Waterfront Centre in Washington, D.C., and the group will receive $15,000 to support their ongoing work. The group's continued efforts are more critical than ever as the U.S. continues to experience extreme droughts that threaten water supplies and crops that depend on irrigation.
These efforts are supported, in part, through USDA-NIFA by the Multistate Research Fund, established in 1998 by the Agricultural Research, Extension, and Education Reform Act (an amendment to the Hatch Act of 1888) to encourage and enhance multistate, multidisciplinary agricultural research on critical issues. Additional funds were provided by contracts and grants to participating scientists. For more information about the microirrigation project, visit http://www.cropinfo.net/MI.
- Author: Ben Faber
A microirrigaiton workshop on use and maintainence of systems in Spanish is being held on three successive dates in San Luis Obispo, Ventura and Fallbrook. These are the same workshop held on July 23, 24 and 25 in the respective areas. The workshops are intended for Spanish speaking workers who maintain and use microirrigation systems. The classes are free and no registration is required. These and future workshops are funded by USDA. For more information contact Lesa Scarborough at:
administration@californiaavocadosociety.org
951-225-9102 Office
951-225-9198 FAX
Click on the flyer below for more details
Irrigation flyer