Posts Tagged: Desert Research and Extension Center

Drip irrigation in arid regions can cut greenhouse gas emissions, improve air quality

Study at Desert Research and Extension Center highlights agriculture's sustainability role

Under the blistering sun of Southern California's Imperial Valley, it's not surprising that subsurface drip irrigation is more effective and efficient than furrow (or flood) irrigation, a practice in which up to 50% of water is lost to evaporation.

But a recent study also concludes that drip irrigation can dramatically reduce greenhouse gas emissions from soil – which contribute to climate change and unhealthy air quality in the region – without sacrificing yields of forage crops alfalfa and sudangrass.

“It was really exciting to see,” said lead author Holly Andrews, a National Science Foundation postdoctoral fellow at the University of Arizona. “The crop yield was at least maintained and in some cases increased, but the water use and gaseous emissions were especially decreased under drip irrigation.”

Desert REC crucial to collecting data

Andrews and her colleagues gathered data from field studies at University of California Agriculture and Natural Resources' Desert Research and Extension Center, a crucial hub of desert agriculture research for more than 100 years. Studies in that context are increasingly important, as much of California and the Southwest becomes hotter and drier.

“We already have this history of looking at drip irrigation at this site, so our study was trying to build on that,” said Andrews, who lauded Desert REC's facilities and staff.

In their study published in Agriculture, Ecosystems & Environment, researchers found that – in comparison to furrow irrigation – drip irrigation in alfalfa slashed per-yield soil carbon dioxide emissions by 59%, nitrous oxide by 38% and nitric oxide by 20%.

Nitrous oxide is a greenhouse gas with nearly 300 times more warming potential as carbon dioxide, and nitric oxide is a precursor to ozone and major contributor to air pollution.

While drip irrigation only decreased water demand 1% in alfalfa, the practice led to a substantial 49% decrease in irrigation for sudangrass. For more fertilizer-intensive sudangrass, drip irrigation also reduced soil emissions of nitrous oxide by 59% and nitric oxide by 49% – the result of drip irrigation making those fertilizers more efficient.

Water management can help mitigate climate change

Studying alfalfa and sudangrass – forage crops with very different fertilizer requirements – was a strategic choice by the researchers. They are number one and number three on the list of most widely grown crops by acreage in the Imperial Valley (Bermudagrass, another forage crop, is number two).

With so much land dedicated to producing these crops, the adoption of drip irrigation at scale could deliver significant benefits to residents' health and quality of life.

“The thought that saving water can increase yields while lowering the emission of trace gases that affect regional air quality and Earth's climate is quite encouraging,” said Pete Homyak, an assistant professor of environmental sciences at UC Riverside who contributed to the study. “This is especially true for the Imperial Valley, an arid region where water is a limited resource and where residents are exposed to bad air quality.”

Homyak, who is affiliated with UC ANR through UC Riverside's Agricultural Experiment Station, said that this study illustrates how changes in water management can substantially mitigate agricultural impacts on the environment.

The study findings should encourage growers to replace furrow irrigation systems with drip irrigation infrastructure – especially in combination with financial incentives from the state, such as cap-and-trade and carbon credit programs, that can help defray high installation costs.

“It really is worthwhile if you're thinking sustainability and environmental activism in how agriculture can actually support climate change mitigation,” Andrews explained. “These practices might be a way that we can start to change that picture a little bit – and make agriculture more sustainable by tailoring irrigation management to local climate conditions.”

In addition to Andrews and Homyak, the other study authors are Patty Oikawa, California State University, East Bay; Jun Wang, University of Iowa; and Darrel Jenerette, UC Riverside.

Drone technology on display at UC research center

The UC Desert Research and Extension Center hosted a workshop for employees and local stakeholders on potential uses for drone technology in agriculture, reported Edwin Delgado in the Imperial Valley Press. 

“The intent of this workshop is to start bringing the knowledge about unmanned aerial systems to the University of California Agricultural and Natural Resources division and the public at large,” said Sean Hogan, coordinator of Informatics Geographic Information Systems for UC ANR. “There is so much curiosity about it right now, it's a growing industry and there is a lot of concern and controversy about the misuses on it.”

The article said the UC system now has the green light to begin using drones. Hogan is holding workshops throughout the state to share his expertise with UC ANR employees and members of the community.

Desert Research and Extension Center director Jairo Diaz said the workshop was important because participants were able to see a demonstration of how the technology works and how it can be applied to the projects and research they are currently working on.

“These workshops that give growers and stakeholders can use in the area are very important because tech like this can help in the near future help find out different types of issues on the field like management of nutrients, water and find out to improve management of field,” Diaz said.

At the UC Kearney Agricultural Research and Extension Center last week, technicians tested a drone that will be used throughout the summer to collect growth data on 600 varieties of sorghum begin produced under different irrigation regimens. With imaging and lidar, the drone collects information on leaf area and biomass in half an hour that would take a full day for a person in the field. 

Read more about the sorghum research at Kearney here.

UC's winter FARM SMART program kicks off at Desert facility

Each winter, thousands of "snow birds" land in the Southern California desert to enjoy the warm and dry climate. They are short-term refugees, many of them senior citizens, escaping cold weather in northern states and Canada. Winter visitors also have the opportunity to attend FARM SMART and learn about the food grown in the vicinity and shipped across the nation, reported Krista Daly in the Imperial Valley Press.

FARM SMART is offered in January and February each year. Attendees learn about irrigation and soils, pick vegetables to take home and enjoy a lunch of local produce.

"We want to pass on the message that agriculture is important," said Sam Urie, FARM SMART manager at the UC Desert Research and Extension Center in Holtville.

The tour was eye-opening for visitors Joe and Nadyne Greschner, farmers from Goodsoil, Saskatchewan.

"What surprised me is that there is no rain here," Joe said.

The 2015 FARM SMART program continues through Feb. 26.

Giant King Grass harvested at UC research center

The first crop of Giant King Grass, a hybrid grass with biofuel potential, was harvested at the UC Desert Research and Extension Center in Holtville this month, reported Ethanol Producer Magazine.

Giant King Grass is a fast-growing, high-yield grass that grows under a variety of soil conditions, according to Viaspace Green Energy Inc. It is propagated vegetatively and, with sufficient rain or irrigation, can grow 15 to 18 feet high in six months.

At the UC Desert Rec, scientists compared two planting processes:

• Planting single nodes that grow into individual plants with some space between them.
• Planting whole stalks continuously end to end, which results in a dense row of plants about six inches apart.

Preliminary results showed the whole stalk planting germinated earlier and grew more quickly. The individual plants had a significant number of skips where the nodes failed to germinate.

Two harvesting regimens were tested:

• Harvest when the plant is 6 to 8 feet tall every two months for animal feed and to produce biogas for anaerobic digestion.
• Harvest when the plant is 15 to 18 feet tall for bioenergy applications, such as direct combustion in a power plant, energy pellets or cellulosic biofuels.

"It was 108 degrees when I arrived in Holtville last Monday evening (Sept. 8, 2014) at 6 p.m.," said Carl Kukkonen, CEO of Viaspace. "Giant King Grass is planted in the worst soil at the University of California site, and still the results are good. I am pleased that Giant King Grass grows well in this extremely hot and dry environment."

The 100,000th visitor takes part in UC's 'Farm Smart' program

The 100,000th visitor to the UC Desert Research and Extension Center "Farm Smart" program walked through the gate last Thursday, reported the Imperial Valley Press. The program, which began in October 2001, annually educates local residents and visitors about the importance of agricultural production.

Larry Mallory of Burley, Idaho, was named the 100,000th visitor and his wife, Sheryll, the 100,001st. The couple are "snowbirds," spending their winters in the mild California desert while their home is buried in snow. They were surprised with confetti, balloons, a commemorative bag and refund of their admission fee for being the milestone guests of the program.

"Farm Smart" was conceived and has been managed over the years by Nancy Caywood-Robertson, DREC educational outreach coordinator, reported the Imperial Valley Press. The program was initially designed for school children, but it blossomed into a destination for school field trips and winter visitors. More than 8,000 take part in the program every year.

Nancy Caywood-Robertson jumps off a bale of hay at the UC Desert Research and Extension Center 'Farm Smart' celebration.

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