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Researchers see more overhead irrigation in California’s future

A center-pivot system irrigates small grain winter forage and summer silage corn production in Denair. (Photo: Jeff Mitchell)
Overhead irrigation systems have revolutionized agriculture across the United States and in other parts of the world, using less water than furrow irrigation and requiring significantly less labor and maintenance than drip systems. But in California, the No. 1 agriculture state in the nation, it hasn't gotten off the ground.

That is beginning to change.

UC Cooperative Extension and Fresno State agricultural production scientists researched overhead irrigation at the UC West Side Research and Extension Center for five years, growing wheat, corn, cotton, tomato, onion and broccoli and comparing them with crops produced under furrow and drip irrigation. With all of them except tomato, overhead irrigation led to similar or increased yields, according to the scientists' report published in the current issue of California Agriculture journal.

“Overall, we are very encouraged by these results, and they reflect the experiences that many California farmers have recently been having with overhead irrigation systems,” said lead author Jeff Mitchell, UC Cooperative Extension specialist. “We've confirmed that overhead irrigation systems work in California. We also concluded that there are opportunities to get even better results with more research and experience, particularly when overhead irrigation is coupled with practices that preserve crop residues and rely on reduced tillage.”

The article co-authors are Anil Shrestha, weed scientist at Fresno State; Joy Hollingsworth, UCCE staff research associate; and Dan Munk, Kurt Hembree and Tom Turini, UCCE advisors in Fresno County.

The tomato yields under overhead irrigation were disappointing, particularly since tomatoes have a prominent role in many Central Valley annual crop rotations.

“This isn't a simple process,” Mitchell said. “You can't just turn it on and let it go. It will require focused and dedicated farmer and researcher attention and innovation to solve.”

The authors are working with a team of Central Valley tomato farmers, processors, irrigation experts and research colleagues to improve overhead irrigation management in tomatoes. They are encouraged by the success of Walnut Grove farmer Michael Boparai, who achieved profitable processing tomato yields with overhead irrigation.

Overhead irrigation systems were invented more than 60 years ago. They now irrigate 50 percent of total U.S. farm irrigated acreage. In Nebraska, 87 percent of irrigated land is under overhead systems. By contrast, in California overhead systems irrigate only 150,000 acres, just 2 percent of the state's irrigated farmland.

Mitchell and his co-authors outlined several factors that contributed to its slow rate of adoption in California:

  • Early adopters ran into serious problems, giving the systems an undeserved bad reputation that persists even though in recent years California farmers are using the systems successfully.
  • Center pivot systems typically leave the corners of the field unirrigated, which can reduce production.
  • Purchase and installation cost of the overhead system is substantially higher than furrow irrigation.

However, the UC and Fresno State research has shown many advantages.

  • Overhead irrigation can be managed remotely and automatically.
  • The system can accommodate different terrain and soil types.
  • Overhead systems requires less maintenance than drip systems in terms of avoiding clogging of emitters and repairing leaks.
  • Overhead irrigation may also help with salinity management by uniformly leaching salts from a crop's root zone.
  • Precision irrigation, including overhead systems, are becoming ever more critical with coming groundwater regulations, surface water cuts and the increasing cost of water for farmers in California.

A significant advantage of overhead irrigation is its compatibility with other farm management technologies that optimize the farming system and reduce costly inputs, including water, fuel, labor and fertilizer.

“We're committed to continuing our work on the whole package – reduced tillage, preserving residue, improving water infiltration, improving soil water-holding capacity and increasing productivity uniformity – a system that we refer to as conservation agriculture,” Mitchell said. “We are working to encourage adoption of conservation agriculture in crops where viability of the system is well established, and facilitate the research and innovation needed to optimize conservation agriculture production in additional crops.”

Posted on Thursday, May 26, 2016 at 10:44 AM

New book traces Los Angeles’ transformation from cows to concrete

From Cows to Concrete: The Rise and Fall of Farming in Los Angeles
After thousands of years as a sparsely populated coastal plain, the Los Angeles Basin underwent two dramatic transformations in the last century and a half, first into an agricultural powerhouse and then into mile upon mile of wall-to-wall American dream homes, shopping centers, freeways, businesses and schools.

“We now have food deserts over what was once abundant farmland,” said Rachel Surls, UC Cooperative Extension sustainable food systems advisor. “Although Los Angeles is not unique in this regard, there's something disconcerting about the speed and scale at which Los Angeles lost its ability to produce food.”

The dramatic conversions of Los Angeles are traced and explained in a new book by Surls and Los Angeles farm and garden authority and UC Master Gardener volunteer Judith Gerber. From Cows to Concrete: The Rise and Fall of Farming in Los Angeles, published by Angel City Press, is available on the publisher's website and from other booksellers.

Though hard to imagine when trapped in a traffic jam on the Santa Ana Freeway, under the pavement, parking lots and buildings are acres of once-productive farmland. Los Angeles County, with more than 10 million residents, now houses a quarter of California's population. But in the first half of the 20th century, Los Angeles was the top farm county in the United States.

In her role with UCCE, Surls works to encourage the newly active school, home, community and urban agricultural community in Los Angeles. She was intrigued to discover that the county now best known for Hollywood, high-rises, and luxurious homes, as well as grinding poverty and homelessness, was once a bucolic farming community. The knowledge sparked research that resulted in her seven-year collaboration with Gerber on the book.

Rachel Surls
LA's transition began when Spanish invaders came to the shore of Southern California to claim the fertile land for Spain. The Native Americans who were hunting, gathering and managing the countryside were folded, often against their will, into missions bent on civilizing the local tribes. Native Americans served as the mission's workforce. Farming at the early missions was successful.

Spanish land grants spawned vast ranchos in colonial Los Angeles that ran thousands of cattle and grew rice, corn, beans, melons and other fruit and vegetables. When Mexico won its independence from Spain, the missions' power declined and the rancheros gained influence. Many communities in Southern California bear the early ranchos' names, such as San Pedro, La Puente and Los Cerritos.

A series of developments led to Los Angeles County's designation as the No. 1 ag country in the nation by 1909. Among them were:

Judith Gerber

  • Successful grape production that was started by the missions to make sacramental wine.
  • A casual experiment by a grape farmer to plant orange trees, which exploded into a citrus growing empire.
  • The arrival of the Southern Pacific railroad expanded the market for LA's perishable produce.
  • The LA Chamber of Commerce led a transition of farming into an organized, sophisticated industry.
  • The discovery of local oil provided affordable fuel to expand production of canned fruits and vegetables, and made irrigation with groundwater possible for more farmers.

Growth of marketing cooperatives, ag research by UC Cooperative Extension, and irrigation and market infrastructure would allow Los Angeles to hold its position as the nation's top farm country for four decades. Los Angeles led the nation in production of walnuts, lemons, strawberries, cauliflower, cabbage, lettuce, tomatoes, corn and hay. 

An aerial view of orange groves near Covina during World War II.
There was a tremendous focus on food production during World War II, but when the war ended, a flood of Americans, including many GIs with low-interest home loans, moved into the region for jobs in burgeoning industries. Between 1940 and 1960, Los Angeles completed its transition from cow-county to sprawling metropolis.

But agriculture has not disappeared, say the authors of From Cows to Concrete. There are small pockets of agricultural land in the urban landscape, such as Richland Farms in Compton, where many people have large lots and keep horses and livestock. The new farm-to-fork movement is prompting families to cultivate vegetables in their backyards and community groups to find vacant space to produce food. LA allows residents to keep honey bees and some residents are raising backyard chickens.

“In a place where poverty is entrenched, with fruits and vegetables neither affordable nor accessible, why not use backyards, vacant lots, and other open spaces to grow healthy food, right in the neighborhoods that need them,” the authors ask. “The story of agriculture in California and Los Angeles is still unfolding.”

Posted on Friday, May 13, 2016 at 11:04 AM
Tags: Rachel Surls (1)

Fire devoured chaparral plots at UC facility to set up a research project

Fire consumes a dense chaparral research plot at UC Hopland Research and Extension Center. (Photo: Evett Kilmartin)
Firefighters set two hillsides ablaze at the UC Hopland Research and Extension Center (HREC) in April, sending flames 50 feet into the air while dense, chest-high chaparral was reduced to a moonscape – all in the name of science.

The prescribed burn was carefully orchestrated by CalFire. Wide swaths of vegetation had been cleared around the 7-acre and 9-acre study areas and the weather carefully monitored before a truck-mounted “terra torch” sent streams of flammable gel into the brush, igniting a raging fire.

The fires at Hopland set up a study for a UC Berkeley doctoral student researching post-fire nitrogen cycling, provided a training ground for new CalFire recruits who will be battling blazes in the summer, and launched a new partnership between HREC and CalFire.

Chaparral shrublands, which cover about 7 percent of California natural lands, are vital California ecosystems. Chaparral contains 25 percent of the state's endemic plant and animal diversity. Nature and Native Americans burned chaparral at regular intervals for millennia, providing fresh new growth for foraging animals.

“After a chaparral fire, you typically get a flush of ephemeral wildflowers, some of which are very rare, which you haven't seen for 30 years or since the last fire,” said Lindsey Hendricks-Franco, a doctoral student at UC Berkeley who is conducting research at Hopland. “The amazing thing about these plants is their seeds can survive in the seedbank for decades. Then heat or smoke or an open canopy can stimulate them to germinate. It can be beautiful.”

The most abundant plant in Hopland chaparral, chamise, is barely fazed by fire. The plant's underground burl will soon sprout after a fire, and chamise seeds readily germinate in ash-enriched soil.

CalFire battalion chief Mike Maynard, left, discusses the controlled burn with researcher Lindsey Hendricks-Franco. (Photo: Evett Kilmartin)
“What I expect to see in the coming months is resprouting adults and thousands of tiny little seedlings,” Hendricks-Franco said.

To understand the role of nitrogen cycling in the post-fire chaparral ecosystem, Hendricks-Franco and her research staff clambered over dense brush before the fire to collect soil samples and place ingenious heat sensors that document the burn temperature. After the fire, she returned to each site to collect post-treatment soil samples and heat sensors.

“It's a challenge to put sensors in a fire this hot. Most heat sensors are destroyed by the intense heat,” Hendricks-Franco said. “I painted four- by four-inch tiles with a variety of heat-sensitive paints. The paints change color at different temperatures. When I collect the tiles, they will give me an idea about the temperatures reached in the fire.”

The controlled burn at Hopland was the first step in rebuilding a partnership with CalFire, said Kim Rodrigues, who has served as the facility's director since 2014. The areas burned in April were previously burned by CalFire for fire research in the 1990s.

“We've been here since 1951 offering applied and relevant research,” Rodrigues said. “It's primarily research on ecosystem management in oak woodlands, grassland and chaparral. Fire on the landscape is a management tool.”

The 5,800-acre research facility is one of nine such centers managed by UC Agriculture and Natural Resources in a variety of California ecosystems, from high desert near the Oregon border, low desert in the Imperial Valley, Sierra Nevada forests and San Joaquin Valley farmland. Hopland is also home to 500 sheep.

Hopland CalFire battalion chief Michael Maynard was the incident commander at the April controlled burns, which he said also fulfilled CalFire objectives.

“It's good to be back here to join up with the University of California,” Maynard said. “The fire falls into our realm of training and expertise and we're helping their realm of expertise, which is research. There are 10 plots on this specific research project, so we'll be back soon.”

Maynard brought in newly hired firefighters for training on setting and controlling a prescribed burn.

“It's important that we brush up on our skills. We have seasonal employees that have hired on early and are participating. So the all-around training value is incredible and pays off later in the summer,” Maynard said.

CalFire will be back at Hopland in the fall to implement another chaparral burn so Hendricks-Franco can compare the fate of nitrogen in areas that burn before the hot, dry summer season to areas that burn in the fall and are followed by rain.

View scenes from the controlled burn in the video below:

Posted on Thursday, May 5, 2016 at 9:00 AM

IPM and pesticide safety a desperate need in Myanmar

Myanmar (formerly Burma) is located in Southeast Asia, bordered by Bangladesh, India, China, Laos and Thailand. I was asked by the United States Agency for International Development (U.S. AID) to travel to Myanmar to use my training and experience as an academic advisor affiliated with the UC Statewide Integrated Pest Management Program and UC Cooperative Extension in Riverside County to share information about basic IPM and pesticide safety.

Myanmar temple grounds.
Myanmar is 261,227 square miles in size, a little smaller than the state of Nevada. About 15 percent of the land is under cultivation. Agriculture makes up 60 to 80 percent of Myanmar's gross domestic product, with the vast majority of agricultural production devoted to rice. Most of the farms are under 20 acres.

With the use of small tractors and other mechanized farm equipment, agricultural development is slightly more advanced in Myanmar than Bangladesh, which I visited in September 2015. Chemical pesticide use in Myanmar is intensive with little regulation or guidance. Chemical contamination of agricultural crops is widespread and mass poisoning does occur.

U.S. AID works to end global poverty and help societies become more independent. One way they do that is by helping countries like Myanmar improve their agricultural development. U.S. AID and Winrock International's Value Chain Project sent me to Myanmar as part of an ongoing effort in Asia to instruct growers in basic IPM and the safe and effective use of pesticides.

An unprotected agricultural worker spraying pesticide.
One of my goals was to try to help growers make a connection between health and the safe use of pesticides. When I first arrived in Myanmar, I found that growers had virtually no pest management information available to them and were unaware of how IPM could be used on their farms. The use of an IPM program focuses on the long-term management of pests by integrating various methods to manage problems. Pesticides are a tool in the IPM “toolbox” and used only when needed and sometimes in combination with other methods.

The growers lack of information on using pesticides safely and effectively seemed to be a recurring theme in Southeast Asia. The growers were not given access to pesticide labels or safety data sheets. In fact, the growers are given virtually no information at all on how to use the chemicals they were applying on their farms. The chemical manufacturers are responsible for this.

Farmers would often apply materials multiple times a week (sometimes more frequently), not knowing about the recommended application rate, re-entry or harvest interval. There's a real need for education in Southeast Asia. Ultimately, the growers and the consumers of contaminated agricultural products are the ones suffering.

Pesticide safety training to media group.

Over two weeks, I held four all-day workshops, mostly for growers, with a final workshop with representatives of local media agencies to teach them basic pest management principles and pesticide safety. When I asked workshop participants if any of them knew someone who had gotten sick or had died from pesticide exposure, virtually everyone raised their hands.

Some growers acknowledged that their practices were making them sick, but that they felt they had few options available to them. As a result, the US-based NGO Internews created a public service announcement (PSA) illustrating the use of personal protective equipment when applying pesticides in Myanmar. The PSA is currently being broadcast on Myanmar television and can be seen below.

This opportunity to educate the public on safe pesticide use is not enough. I recommend monthly pesticide tours be set up across the country to emphasize the need for safe and effective use of pesticides. The use of extension outreach is invaluable in situations like this.

Interviewing a tomato farmer on Inle Lake.
Some of the most remarkable farming I have ever witnessed is on Inle Lake, the second largest of Myanmar's lakes. The agricultural population of the lake, which is part of the World Network of Biosphere Reserves, live in stilted homes primarily made of wood and bamboo. The tomato farmers build up dry ground to farm by raking up soil from the lake bottom and amending the lake soil with aquatic plants that they also rake up from the lake bottom. The farmers do all of their work from boats, including spraying pesticides.

The facilitation of the University of California's Global Food Initiative by U.S. AID and Winrock International is extremely useful. The world as we know it is shrinking with globalization of people and products. We need to reach out to others and give them the benefit of our experience. UC IPM is doing that.

Posted on Thursday, May 5, 2016 at 8:30 AM
Tags: IPM (13), Myanmar (1), Vonny Barlow (2)

Fighting drought with soil

Soil is an often overlooked tool to fight drought.
A team of University of California scientists recently received a $1.69 million grant to use several UC agricultural research stations to study an often overlooked tool to fight the drought: soil.

The team, led by Samantha Ying, an assistant professor of environmental sciences at UC Riverside, received the grant from the University of California Office of the President.

The funding will allow for the establishment of the University of California Consortium for Drought and Carbon Management (UC DroCaM), which will design management strategies based on understanding soil carbon, the soil microbiome and their impact on water dynamics in soil.

The researchers will conduct field and lab research on microbiological, biophysical, and geochemical mechanisms controlling soil formation and stability under different row crops (tomatoes, alfalfa, wheat), farming practices (carbon inputs and rotations) and irrigation methods (furrow and flood, microirrigation).

Samantha Ying, an assistant professor of environmental sciences at UC Riverside.
Information on mechanisms will be integrated into a regionally-scalable predictive model to describe soil carbon dynamics and estimate the response of agricultural systems to drought.

Field research will initially be conducted at three UC Research and Extension Centers (Kearney, West Side and Desert) the Russell Ranch Sustainable Agriculture Facility near UC Davis.

Recommendations will then be made for broader monitoring and field experiments throughout the state based on input gained from local growers and citizens at workshops at the agricultural research stations. Ultimately, the hope is to expand and involve all nine research and extension centers from the Oregon border to the Mexican border.

“Having agricultural research stations throughout the state is a huge part of this project,” Ying said. “It is going to help us create one of the best research centers in the country focused on soil and drought.”

There is also a public engagement component. Citizens will be recruited to participate in workshops to learn how to monitor and sample their local soils. Information will then be imputed into an online soils database that will help create a map of the biodiversity of agricultural soils in California.

Ying's collaborators are: Kate Scow and Sanjai Parihk (UC Davis); Eoin Brodie and Margaret Torn (UC Berkeley); Asmeret Berhe and Teamrat Ghezzehei (UC Merced); and Peter Nico and William Riley (Lawrence Berkeley National Laboratory).

The grant is one of four awards totaling more than $4.8 million from University of California President Janet Napolitano's President's Research Catalyst Awards.

Posted on Monday, May 2, 2016 at 12:25 PM

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