Idaho W-128 Micro Irrigation Report, 2003

Progress Report on Microirrigation in Idaho, 2003.

Progress Report on Microirrigation in Idaho
W-128 Regional Research Committee
Howard Neibling
Biological and Agricultural Engineering
University of Idaho

January 1, 2003 to December 31, 2003

Publications:

Qureshi, Z.A. 2003. Impact of Late-Season Irrigation Management on Malting Barley Yield and Quality. Ph.D. Dissertation. Biological and Agricultural Engineering Department, University of Idaho. Moscow, ID. 220pp.

Neibling, W.H., M. Colt, S. Bell, J. Robbins. 2003. Watering Home Lawns and Landscapes. University of Idaho Current information Series #1098. 8pp.

Presentations:

Urban programs discussing microirrigation applications and irrigation scheduling:

· Neibling, W.H. "Irrigation management in the home lawn and garden". Presented at the master gardener training, Hailey, ID.

· Neibling, W.H. "Irrigation management in the home lawn and garden". Presented at the master gardener training, Jerome, ID.

· Neibling, W.H. "Irrigation management in the home lawn and garden". Presented at the master gardener training, Twin Falls, ID.

· Neibling, W.H. "Types of equipment and irrigation strategies for roses". Presented at the Twin Falls Rose Society meeting, 6/12/03.

Agricultural programs discussing irrigation scheduling tools:

· Neibling, W.H. "Plant and soil properties important to irrigation system design and management". Presented to irrigation equipment dealer employees at the annual dealer employee workshop at the Idaho Irrigation Equipment Association Show.

· Qureshi, Z and W.H. Neibling. "Coordination of irrigation and harvest of alfalfa to minimize drying time without sacrificing yield. Presented at the 2003 Idaho Irrigation Equipment Association Show, Idaho Falls on both January 8th and 9th.

· Neibling, W.H. "Using Hansen meter output to schedule irrigation on potatoes in different soils". Presented at the IDWR / UI Irrigation field day, Rexburg, ID, 6/17/03.

· Neibling, W.H. and W. Weihing. "How much water do you really need?" Presented at the UI / IDWR irrigation workshop, Montpelier, ID.

· Neibling, W.H. "Alfalfa water use efficiency and management: the risks of deficit irrigation" Presented at the general session of the Western Alfalfa and Forage Conference, Reno, NV. About 600 attended

· Neibling, W.H. "Managing center pivot systems in forage production" Presented as a breakout session at the Western Alfalfa and Forage Conference, Reno, NV. About 120 and 70 attended the two sessions.

· Neibling, W.H. "The risks of deficit irrigation in alfalfa production" Presented at the 2003 Washington Hay Growers annual meeting, Pasco, WA. About 200 attended

· Neibling, W.H. "Managing center pivot systems in forage production". Presented at the 2003 Washington Hay Growers Meeting, Pasco, WA. About 200 attended.

· Neibling, W.H. "Alfalfa Water Use Efficiency and Management". Presented at the 2003 Oregon Hay Growers meeting, Christmas Valley and Burns, OR. About 20 and 50 attended.

· Neibling, W.H. "Managing center pivot irrigation". Presented at the 2003 Oregon Hay Growers Meeting, Christmas Valley and Burns, OR. About 20 and 50 attended.

· Neibling, W.H. "Management of alfalfa under water-short conditions, and late season irrigation of malting barley". Presented at the 2003 San Luis Valley Haygrowers Meeting, Monte Vista, CO. About 150 attended.

· Neibling, W.H. "Irrigating alfalfa under water-short conditions". Presented at the Blaine/Camas Alfalfa School, Fairfield, ID. About 20 attended.

· Neibling, W.H. "Managing alfalfa irrigation during water-short periods". Presented at the Eastern Idaho Hay Growers Meeting, Rexburg, ID. About 30 attended.

· Neibling, W.H. "Using soil moisture sensing equipment for water management in alfalfa production". Presented at the UI Forage Field Day, Kimberly, ID. About 60 attended.

Graduate students:

Zahid A. Qureshi, Ph.D. Biological and Agricultural Engineering (graduated May 2003)

Progress of Work and Principal Accomplishments:

Objective 1: To evaluate and refine microirrigation management strategies to promote natural resource protection and optimal crop production. (including irrigation scheduling tools)

A project was developed in 2002 to demonstrate Watermark soil moisture sensors and a Hansen data logger as a tool for improved irrigation scheduling. One aspect of the project was to compare water use and crop yield and quality on a portion of each field managed by the farmer with that managed with soil sensors. On January 6, 2003, an extension of the project was approved through December 31, 2003. Five grower fields were selected and irrigation scheduling modified during the 2003 growing season based on soil moisture sensor readings. Because of the record high temperatures during this year, modifications in the growers irrigation scheduling were not as pronounced as would be expected during a normal season.

Fieldwork has only been completed within the last week and results are now being compiled and analyzed. The report will be completed by the December 31, 2003. The major education thrust will be made at the Snake River Sugarbeet Conference scheduled for January 15-16, 2004, at the Nampa Civic Center, Nampa, Idaho. Three growers who have been using these recording meters and soil moisture sensors for irrigation scheduling have agreed to participate in the Conference and share their experiences and the increased return they've calculated as a result of this program. These are growers who have worked with several team members in this project in past years and have adopted the practice in their operations.

Cooperative work was also initiated with Dave Ellison (agronomist) and Jeff Skow (fieldman) for Amalgamated Sugar to set up comparisons between watermark / Hansen logger scheduled areas and farmer - scheduled areas of two fields in the Rupert area. They were anxious to see if these devices would be useful to recommend to growers for irrigation scheduling. Except for a few cut wires, the systems worked well.

Cooperative work with Lance Brower, Fremont Co. involved a one-day irrigation workshop and additional work with Lance on technical support, evaluation and data interpretation for Watermarks / Hansen meters on 10 grower potato fields. One of the major keys to grower usage was a set of laminated cards developed by Howard Neibling. These cards show remaining usable soil water in inches and as % available, and the water depth required to refill each foot of soil to field capacity for a range of watermark readings for 4 soil textural classes.

Objective 2: To improve, modify, and evaluate microirrigation system design and components for natural resource protection and optimal production.

Widening the spacing between adjacent tapes can reduce cost. Maximum spacing is a function of crop, spacing and discharge of emitters along each tape and soil capillarity. One cooperator in Custer County wanted to use SDI to water the entire soil surface for establishment and maintenance of native grasses and other near-stream vegetation. Maximum effective spacing for that soil type and native grasses and shrubs was unknown so tests were performed to evaluate several tape spacings. The soil profile was about 6-8 inches of silt loam soil, underlain by a number of layers of silt/gravel. Based on tests, a spacing of 30 inches along the tape and 42 inches between tapes when buried 6-8 inches deep gave acceptable performance. About 90 acres of tape were installed. Wetting fronts at the surface were separated by about a 6- 10-inch dry soil strip. The dry strip was narrower at the tape depth. Winter precipitation should germinate grass seed in this area and water from the drip system will be sufficiently close to support grass growth in this initially dry zone. This site can now be used as a demonstration site for those interested in a similar application.

Tape spacing was also evaluated at a second site on a Portneuf silt loam near Twin Falls. Tape spacings for irrigated pasture were 24 and 48 inches. After about 7 days of run time, the initially very dry soil was completely wetted at the surface for the 24-inch spacing. On the second portion of the area, near complete wetting on the 24-inch spacing was achieved in 3 days with a 12 hour on- 12 hour off cycle. The wetting fronts are still far apart at the surface on the 48-inch spacing .

Objective 4: To promote appropriate microirrigation technologies through formal and informal educational activities.

Significant activities this last year included:

· Work with Lance Brower (potatoes), Cindy Kinder (alfalfa), Joel Packham (alfalfa), Matt Schuster (beets) and Stan Gortsema (beets) in a supporting role for their demonstration field activities with Watermark sensors and Hansen data loggers. This typically involved answering questions about sensor installation, data logger installation, interpretation of readings, and general equipment troubleshooting. Useful data were obtained from almost all sites and growers were generally happy and willing to use the equipment again.

· A cooperative study with Jason Ellsworth and Brad Brown on optimization of irrigation / fertility variables was conducted at Kimberly and Parma. Crop yield and quality data, soil moisture data and soil fertility data were collected from each field. Irrigation method was surface drip irrigation. Results will be presented this winter.

Urban Water Management Demonstration Projects: Information on improved water management and water-saving opportunities for the use of microirrigation must be delivered to individual homeowners. To affect a change in irrigation management, each individual must be motivated by desire to conserve and protect the environment, or by potential water cost savings. Educational materials will be developed cooperatively with interested county extension faculty to address both aspects. Two major barriers to technology transfer are 1) the ability to deliver the information to the target audience, and 2) the ability to convince the audience that the desired change is beneficial and worthwhile. Portions of the project approach are designed to address each barrier. Public service announcements highlighting various aspects of water conservation will be developed by a joint UI / media effort. Another possibility is a daily water use graphic in the local TV weather segment.

Demonstration projects are required to show that suggested management changes can save water and yet produce the desired lawn appearance. Proposed sites are in Twin Falls at the KMVT lawn and two homeowner sites and a cooperative effort with the city of Twin Falls in a city park. In addition, three sites in Jerome will be established. A commercially available soil moisture sensor / sprinkler control device will be installed at each site to allow sprinkler to operate only when water is really needed. At each site, measurements to be made include: daily metered water applied on conventional and improved management areas, soil moisture monitoring at 1, 2 and 3 foot depths using Watermark sensors and Hansen data loggers, weekly soil moisture monitoring by neutron probe (if cooperators approve), and evaluation of lawn appearance. Historical water use per unit ET and measured current water use per unit ET will be used to evaluate water savings on project sites. Information generated from demonstration sites on water savings, lawn appearance and the success of alternative irrigation system controls will be made available on the web site for public access, and will be used as the basis of water conservation educational efforts during late summer 2003, spring 2004 and summer 2004.

An initial version of a lawn and tree irrigation web site was developed using water-quality related funding. The site is CD-based and is currently being tested by a number of interested county faculty. It will be enlarged and improved as a part of the new urban water conservation project that received funding in September.

Usefulness of Findings:

Objective 1:

Outcomes of research and educational activities with Lance Brower, Fremont Co.:

· Growers were pleased with the equipment and most did change irrigation practices
· Tuber quality was better than last year with less water
· Minimum revenue improvement was $130/ac, with a maximum of about $400/ac.
· Potatoes on one field were unmarketable except for low-grade processing last year. This year with better water management, potatoes were very good for processing. Income difference was about $1,000,000, had last years crop been able to be stored and marketed last winter.
· The potato packer involved with these fields ordered equipment for every field that supplies his packing house this year.

Outcomes of work with county extension faculty and alfalfa growers:

· A farmer in Fairfield, used Watermarks and Hansen meters installed and left in place last winter to evaluate when to turn on irrigation water this spring. On the portion of the field where he started "early", yield was nearly 0.5 T/ac higher than where irrigation was started at a more "normal" time.

· One grower in Bear Lake County reported that after using the Watermarks and Hansen meter, he had completely changed the way he irrigated alfalfa. He could see that he had been irrigating too infrequently and applying too much water. He changed from 24 to 12-h sets and observed better crop production.

· Another grower in Bear Lake County adjusted the management of his center pivot based on Watermark and Hansen meter information.

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