Davis, Calif., (October 6, 2017) – Belching beef and dairy cows emit a significant amount of methane, sending a potent greenhouse gas into the atmosphere where it can contribute to climate
A steer at UC Davis that is part of the Mootral trial, which aims to reduce greenhouse gas emissions from livestock.
In European studies, supplementation with just 15 grams of a formulation called Mootral, derived from garlic and citrus extracts, killed bacteria in the cow’s gut that produce the gas emitting from the animals’ mouths and nostrils. Methane emission was cut 30 to 50 percent. Kebreab and his staff are feeding the supplement to nine California cows at the UC Davis farm and comparing their emissions with nine cows on identical rations minus Mootral.
UC ANR researcher Ermais Kebreab is leading a trail at UC Davis comparing cattle that received the Mootral supplement with those that did not.
“This research is highly relevant in California,” Kebreab said. “The state is committed to reducing its greenhouse gas emissions to 40 percent of 1990 levels by 2030. We need to reduce the environmental impact of livestock production.”
Davis, Calif., (September 12, 2017) – Innovative cooling technologies tested on dairy cows at the University of California, Davis, are addressing the long-standing challenge of keeping dairy cows cool in heat-stressed California.
Cows cool off at UC Davis. (Paul Fortunato/UC Davis)
Standard livestock cooling methods, such as fans and sprinkling cows with water, require significant amounts of electricity and water. The new technologies, being tested at UC Davis by the Western Cooling Efficiency Center and the Department of Animal Science, are designed to reduce water by up to 86 percent and electricity by up to 38 percent over conventional methods.
Milk production and heat stress
Milk is the most valued agricultural commodity in California, with $9.4 billion in retail sales in 2014. Roughly one in every five dairy cows in the nation lives in California. In addition to disturbing the cow, heat stress is a major cause of diminished milk production in dairy cows, with annual losses directly related to heat stress exceeding $800 million.
“The process of rumination, where cows ferment their food, produces a lot of heat, as does milk production itself,” said Cassandra Tucker, a professor in the Department of Animal Science who focuses on dairy cattle welfare. “When the outside temperatures also rise, it’s a challenge for the animal in how she’s going to try to keep cool. This project is trying to reduce the energy and water use associated with that to help both the cows and the dairy producers.”
How it works – The technologies involve two approaches. The first is conduction cooling, where the bedding area is cooled using heat exchange mats placed where cows lie down. To reduce energy consumption, water flowing through the mats is cooled through a novel evaporative chiller called a Sub-Wet Bulb Evaporative Chiller.
The second approach is targeted convection cooling, which uses fabric ducting to direct cool air onto the cows while they lie down and when they eat. The air is cooled using a high-efficiency direct evaporative cooler.
“This is an exciting research opportunity for UC Davis to combine our expertise in engineering with our expertise in animal science,” said Theresa Pistochini, senior engineer at the Western Cooling Efficiency Center. “There is significant potential to apply existing technologies in a novel way to reduce both energy and water used to cool dairy cows. Through this project we aim to design, test and demonstrate an efficient alternative.”
The project is part of a four-year, $1 million grant from the California Energy Commission to help improve water and energy efficiency in California’s dairy industry. The data being collected now will help determine which technology the team should use to pilot at a commercial dairy in a future phase of the project.
Davis, Calif., (August 30, 2017) – If you grew up in the 1980s or 1990s (or were a child at heart during that era), the famous Powers of Ten film likely left an indelible mark in your mind.
The film starts with a couple lounging on a picnic blanket and zooms out to the outer reaches of the universe, then back in to peer into the microscopic world of the human body: from white blood cells to DNA, and finally down to the proton of a carbon atom.
In its short 9-minute run time, Powers of Ten manages to inflame an existential angst about the size of a single human life while at the same time connecting the viewer to the beauty of the universe and the human body.
As a high school student watching the video, it filled me with the same sense of awe that I felt the first time I heard Carl Sagan’s famous quote that “we are all made of star stuff.”
Powers of Ten reminds us that looking at the world from different perspectives, from the very tiny to the immensely large, helps create a better understanding of the natural world, our place within it, and how we can impact it for good.
Had Powers of Ten returned from outer space by zooming into a piece of soil rather than a the human body, it would have explored the billions of living creatures in one handful of soil, slowly scaling down from millipedes to earthworms to ants to nematodes to protozoa, and finally down to the soil’s bacteria and fungi that make up the base of the soil food web.
The video might then have looked a lot like the recent workshop at the Russell Ranch Sustainable Agriculture Facility, which served as a science fair for farmers and researchers to learn about the minuscule but powerful soil microbe.
Through hands-on demonstrations using everything from soccer balls to building blocks, sponges, and food coloring as props, graduate students and postdoctoral researchers in UC Davis’ Soil Microbial Ecology Lab lead by soil microbiologist and professor Kate Scow explained the role and importance of these invisible players in soil to the people who depend on direct observation for much of their work: farmers.
While farmers often have a baseline knowledge about soil microbiology and its importance on the farm, “the science is evolving so quickly at this point, that it can be hard to keep up,” said attendee Margaret Lloyd, UC Cooperative Extension advisor who works with small-scale farmers in Yolo and Sacramento counties.
The workshop coupled foundational principles of soil microbiology with practical on-farm management situations, making the case for farmers to actively consider soil bacteria, fungi, and other micro organisms in their decision-making process.
Jessica Chiartas, a fourth-year graduate student in soil microbiology and one of the workshop organizers, is somewhat of a soil science evangelist.
Her hope was to help workshop attendees better understand that “soils are not just physical, chemical systems. A majority of the processes that take place underfoot are biologically driven. Soils are living and breathing bodies and much like us, they need to be fed, covered, and protected from disturbance” in order to function in the long term.
The scale of microbial activity in soil makes it challenging to help farmers dig into just what scientists are talking about when they talk about microbes.
“It’s important to talk about the scale of microbes,” Chiartas said. “So much of what goes on in soils is mediated by microbes and the scale that they operate on is far different than the scale we measure them at. Our typical method of soil sampling and analysis is analogous to harvesting whole fields of crops, chopping them up, throwing them in a heap and then trying to glean information about the individual plants.”
The presenters at the soil health workshop used vivid analogies to translate the abstract results of scientific research and hard-to-imagine scales into concrete, relatable concepts.
A single gram of soil may contain a billion bacteria, and several miles of fungal hyphae, the web-like growth of fungus. Translated into human scale, the numbers are mind boggling.
If a single microbe were a 6-foot-tall person, then a single millimeter of soil would be as tall as the empire state building. A typical soil bacterium contains as many DNA letters in its chromosome as two copies of “War and Peace.” A stack of copies of “War and Peace” equivalent to bacterial DNA from a single teaspoon of soil would be larger than the Great Pyramid of Giza.
The metaphors of scale are a fun thought experiment, and they could provide a jumping-off point for a discussion between farmers and scientists essential for improving our current understanding of soil as a living system. Climate change is expected to amplify the effects of soil erosion, compaction, nutrient leaching and other issues common in our current agricultural systems.
“We need improved management that works with the soil ecosystem to increase crop production while enhancing soil health,” said Radomir Schmidt, a postdoctoral researcher and workshop organizer. ”That’s going to take a concerted effort and open dialog between farmers, scientists, and citizen scientists to discover, test, and implement these methods in the real world.”
We are now in the era of “soil information revolution,” Schmidt said. As our knowledge of the soil microbiome expands, implementing this knowledge in agricultural practice is more and more possible.
Postdoctoral researcher Radomir Schmidt discusses the scale and diversity of microbes in different agricultural management systems
This graduate student cohort is well-positioned to make the necessary connections, learning from farmers while helping them zoom in to see the essential lifeforms that impact their farm, then zoom out to help make decisions that are good for the farmer, good for the crop, and good for the microbe.
Farmers in the Davis area will have another opportunity to learn soil health fundamentals at a workshop this fall hosted by the UC Sustainable Agriculture Research and Education Program and Russell Ranch Sustainable Agriculture Facility. Details about the workshop will be posted here.
Davis, Calif., (July 24, 2017) – Kurt Kornbluth and Elizabeth Mitcham are the recipients of UC Davis’ inaugural Chancellor’s International Engagement Achievement Awards, while Alan Bennett received an honorable mention.
The award recipients: Elizabeth Mitcham, second from left; Kurt Kornbluth, center; and Alan Bennett, second from right. They are flanked by Ralph J. Hexter, interim chancellor, and Joanna Regulska, vice provost and associate chancellor of Global Affairs. (Chanae Allred/UC Davis photo)
Interim Chancellor Ralph J. Hexter presented the awards during a ceremony in the multipurpose room of the new International Center.
“Our tendency to form strong global connections and think beyond borders is one of the reasons why the Times Higher Education rankings this year rated us the fourth most international public university in the nation,” Hexter said.
Joanna Regulska, vice provost and associate chancellor of Global Affairs, said the new awards program — open to all full-time faculty and staff — aligns with her unit’s efforts to:
“Interconnect all at UC Davis by inspiring global curiosity, understanding and engagement.”
“Develop and support the capacity of all members of the UC Davis community — faculty, students, scholars, staff and alumni — to successfully engage in building and sustaining partnerships, collaborative research initiatives, and academic and teaching programs with international peer institutions, partners and colleagues.
“Expand upon the impactthat UC Davis is making toward solving global problems, educating an interculturally competent citizenry and engaging in world-class research.”
Kurt Kornbluth
He is an adjunct assistant professor in the Department of Biological and Agricultural Engineering in the College of Engineering, and founding director of the Program for International Energy Technologies, which, through its D-Lab courses, involves students in solving real-life energy problems in developing countries.
His nominator, Jean VanderGheynst, professor, Department of Biological and Agricultural Engineering, said: “In an era of food, water, energy and climatic uncertainty, it is critical to acknowledge the faculty leaders who are developing roadmaps to climate neutrality, engaging students and scholars in problem-oriented, client focused learning, and sharing ideas and resources with faculty and researchers from UC Davis, the UC and universities abroad.”
Indeed, she said, Kornbluth “has initiated substantial international teaching, research and service efforts in climate neutrality, and for this reason is an ideal candidate for the Chancellor’s International Engagement award.”
She cited as an example the Kornbluth-led Lighting the Way Zambia project. “The economic, health and environmental costs of kerosene, candles and other fuel-based lighting are well documented,” VanderGheynst said. So, with funding from the World Bank, PIET designed, manufactured and distributed portable solar lights.
“The lab advances fruit and vegetable research to support the needs of smallholder farmers in developing countries,” Dillard wrote. “As part of this initiative, the Horticulture Innovation Lab has collaborated with more than 18 U.S. universities and 200 organizations in Latin America, Africa and Asia with projects spanning the horticultural value chain.”
“Over the years, many of the projects led by UC Davis faculty with UC Davis graduate students and researchers, have led to national and international collaborations with other universities and research organizations.”
Mitcham has been a faculty member and Cooperative Extension postharvest specialist since 1992. Through her long affiliation with the university’s Postharvest Technology Center (she’s a former director), she has trained agricultural professionals from more than 40 countries.
“She has contributed to long-lasting horticultural science as a way to improve health and nutrition globally, while enhancing the role of women in developing countries,” Dillard wrote. “She has been an inspiration for many students, staff, and faculty for her commitment to international development activities.”
“Throughout his career, Dr. Bennett has consistently demonstrated his vision and dedication in driving international programs for domestic and global academic institutions,” wrote his nominator, Pablo Zamora, associate director of the UC Davis-Chile Life Sciences Innovation Center.
“By working closely with 60 universities and the Rockefeller Foundation, he was able to structure a public initiative (PIPRA) to drive patented agricultural technologies for international development. … Furthermore, he used this platform, with the support of the UC Davis School of Law, to found the Licensing Academy whose successful, ongoing mission is to train technology managers in more than 50 developing countries.”
Bennett founded the UC Davis-Chile Life Sciences Innovation Center in 2015, collaborating with the Chilean government in its intent to cultivate international climate through technology and innovation.
“UC Davis-Chile has had profound impact and continues to be a pioneer in the internationalization of UC Davis in Latin America. These highlighted contributions exemplify Alan’s continuous efforts to achieve the university’s land-grant mission at home and abroad.”
Davis, Calif., (June 30, 2017) – When the UC Davis Fire Department trained with campus experts this spring on how to corral loose animals and load horses into trailers, the firefighters likely had no idea they’d be putting their new skills to use so soon.
On June 19, they did just that, evacuating a barn full of goats, chickens and a young calf as a grass fire barreled toward it. And thank goodness they did, because the wind-stoked flames eventually consumed the barn.
“Instead of futily attempting to save the barn, my decision was to direct the crew to evacuate the animals as quickly as possible and protect the adjoining house,” Acting Capt. Ben Rizzo said.
The incident began as a car fire that spread to the grass on a property near Dixon. Authorities called in reinforcements — and that brought out the campus Fire Department.
“Rizzo and his crew were able to immediately draw on their recent animal handling and rescue trainingprovided by the UC Davis School of Veterinary Medicine and Department of Animal Science,” according to a report on the veterinary medicine website.
“Their hands-on experience allowed them to prioritize the animal life risk and understand what was needed to move them. The firefighters were able to get the animals from a place of immediate danger to a safe refuge. Swift actions and a good understanding of animal behavior and handling certainly saved numerous lives that evening.”
UC Davis Fire Capt. Nathan Potter was one of the firefighters who trained with large animals this spring.
In conjunction with the UC Davis Horse Barn, Green developed a risk-based approach to situations in which firefighters encounter animals that need to be rescued or safely moved from harm’s way.
“Firefighters and other responders have to take very different actions in response to the presence of animals at any incident they attend compared to our typical calls for service,” Green said. “Risks range from a domestic pet protecting its environment at home, to defending its owner in a car crash, to a wildland fire where trapped and scared large animals require evacuation.”
UC Davis’ collaboration with Green will extend to the Incidents Involving Animals Conference, Oct. 21-22, hosted by the School of Veterinary Medicine in Partnership with the British Animal Rescue and Trauma Care Association.
Cody Kitaura and Rob Warren contributed to this report.
With the early season rains and floods, many growers have wondered what kind of impact that might have had on rodent populations on the farm, and want to know how to manage them moving forward. Check out California Ag Network’s video interview with Wildlife Specialist Roger Baldwin from UC Davis to find the answers.
Davis, Calif., (June 21, 2017) – The University of California, Davis, has purchased an anaerobic biodigester that has operated on campus since 2014 and plans to open an adjacent composting facility to create a more comprehensive waste-management strategy. The purchase will allow UC Davis to maintain an active research program on anaerobic digester technology and potentially expand research opportunities in compost application for healthy soils and carbon sequestration.
UC Davis ownership will also allow the campus to develop a comprehensive organic waste disposal program that meets the newest state requirements, reduces vehicle trips carrying waste to off-campus sites, and provides better control over current and future costs.
“The digester has helped demonstrate feasibility of the technology in a medium-sized plant, which was an important reason behind construction of the plant on the UC Davis campus,” said Camille Kirk, director of sustainability at UC Davis. “Looking forward, we’re combining leading-edge research with a comprehensive approach to managing organic waste on campus.”
Opened in April 2014, the campus biodigester was built, owned and operated by CleanWorld, with a ground lease from UC Davis. The commercial-scale biodigester is designed to generate electricity from methane gas formed from the digestion of organic wastes. It uses technology invented by Professor Ruihong Zhang at UC Davis and licensed to CleanWorld by UC Davis. The facility was launched with support of grants from the U.S. Department of Energy and the California Energy Commission.
The transfer of these assets to UC Davis fulfills CleanWorld’s mission to focus on technology rather than operating facilities, with the added benefit that UC Davis is a world-class institution dedicated to furthering research in the quest to find beneficial uses for organic waste.
As a renowned research institution and leader in environmental sustainability, UC Davis is interested in the research and operational opportunities offered by an on-campus biodigester and composting facility. UC Davis officials therefore decided to purchase and operate the biodigester. The cost of purchasing the equipment is estimated at $600,000 plus $450,000 for facility upgrades and permitting costs.
The university intends to construct a composting facility to manage effluent and waste products from the biodigester, as well as other organic wastes generated by the campus that cannot be fed to the biodigester and instead are currently hauled away. Costs of constructing the proposed composting facility are to be determined.
Davis, Calif., (May 30, 2017) – Seven UC Davis students and alumni are headed to three continents as cultural ambassadors. Three have won prestigious grants, awarded by the Fulbright U.S. Student Program to promote educational and cultural exchange, and will conduct research in Ukraine, Indonesia and India; four others have been awarded the grants to teach English in Malta, Colombia, Malaysia and Germany.
They are:
Jennifer Hoover of Davis, California
Gillian Irwin of Davis, California
Nina Fontana of Davis, California
Ana Skomal of Bonita, California
Joshua Paull of Walnut Creek, California
Amanda Eke of Sacramento, California
April Kersh of Seattle, Washington
The program of the U.S. Department of State awards about 1,900 grants annually to fund airfare, room and board, health insurance and incidental expenses for one academic year of international graduate study, advanced research and teaching in 140 countries. Students and young professionals are selected on the basis of their academic and professional achievement, record of service and leadership.
Jennifer Hoover, India: Jennifer Hoover is back at the UC Davis Craft Center where she fell in love with textile arts. (Gregory Urquiaga/UC Davis)
Hoover, who earned a bachelor’s degree in anthropology from UC Davis in 2000 and soon began work as a teacher, later took classes for personal interest at the Craft Center on campus. Those classes in the textile arts would lead her to enroll in UC Davis graduate studies, do research at sheep-shearing stations in California, earn a master’s degree in textiles in 2016, and make three visits to India. Now Hoover is headed to the Himalayan state of Himachal Pradesh in India. She will examine wool production practices from shearing through weaving to help bridge the gap between shepherds who discard wool or sell it for export and craftspeople who buy synthetic yarns and import wool.
Gillian Irwin, Indonesia: Doctoral student Gillian Irwin practices as part of the UC Davis Gamelan Ensemble, which performs music from Indonesia. (Gregory Urquiaga/UC Davis)
Irwin, who has already studied in Indonesia and taught English there with a Fulbright grant, has received two new Fulbright awards to spend 12 months in Indonesia. Through the Critical Language Enhancement Award, the doctoral student of ethnomusicology will study to improve her already advanced skills in the Indonesian language. Then she will research how the government’s 2013 standardized curriculum, which seeks to develop moral character, has affected music programs in middle and high schools. She will research Indonesian documents in the national archive, conduct interviews and observe music classes. After completing her doctoral degree, Irwin plans to pursue her research through a fellowship and later be a university professor.
Nina Fontana, Ukraine: Doctoral student Nina Fontana will return to her roots to do research in the mountains of Ukraine. (Gregory Urquiaga/UC Davis)
Fontana, a doctoral student of ecology, will live among the Hutsul people of Ukraine’s Carpathian Mountains to explore their traditional ecological knowledge for managing and using nontimber forest products including wild edible plants and mushrooms. Of Ukrainian heritage, she said the region is considered the Amazon of Europe, and its flora species provide key indicators of ecosystem health in response to climate change. Fontana’s aim is to create a database that captures the relationship between the highlanders’ gathering practices and plant productivity to inform land stewardship policy and conservation.
Amanda Eke, Malta: UC Davis student Amanda Eke, a musician who manages artists and produces music, hangs out in a downtown Davis record store. (Gregory Urquiaga/UC Davis)
Eke, who expects to graduate in June with a bachelor’s degree in gender, sexuality and women’s studies, will teach English at the University of Malta. A musician who plays six instruments, manages artists and produces music, she plans to incorporate into her lessons hip hop as well as the Maltese music tradition of Ghana, a rhyming, conversational form of ballad or argument. She has presented her research on the artistry of black female musicians and their roles as political activists at Harvard and Purdue universities. She also tutors at the Juvenile Detention Facility and the Yolo County Jail, both in Woodland, California. Eke plans to pursue a doctorate in cultural studies and then, as a university professor, develop courses that enhance cultural knowledge and understanding through different concepts of identity.
Ana Skomal, Malaysia: Ana Skomal, here leading a class at UC Davis, hopes to share her love for yoga in Malaysia. (Tim McConville/UC Davis)
Skomal, who will complete her undergraduate studies in food science and technology this fall, will teach English to schoolchildren in rural Malaysia. Fluent in Spanish and English, she plans to hold yoga classes as part of a women’s health club she will start in her community there. Skomal has done a health internship in India and studied abroad in China. She has been active with the student organization Chicanos in Health Education, served as both a medical volunteer and translator at the Joan Viteri Memorial Clinic in Sacramento and founded the Yoga Club at UC Davis. She plans on attending medical school to become a family or primary care physician.
Joshua Paull, Colombia: Joshua Paull, fluent in English and Spanish, is bound for Colombia. (Karin Higgins/UC Davis)
Paull will teach English in Colombia as he pursues an early career teaching English as a second language in Latin America and eventually to children of American military personnel stationed abroad. A graduating senior with majors in history and international relations, he is fluent in English and Spanish. Paull has studied abroad in Cuba, volunteered with an environmental organization in Guatemala and tutored immigrants through the Solano County Library. Included in his luggage will be his saxophone so he can get involved in cumbia and salsa bands.
April Kersh, Germany: Kersh, who earned a bachelor’s degree in English in 2016, will teach English in Germany.
San Francisco, Calif., (May 25, 2017) – A federal jury has ruled in favor of the University of California in its lawsuit with two former UC Davis strawberry breeders and the private breeding company they created with UC-owned plants. A separate jury is expected to decide issues related to damages at a later time.
These strawberry plants are part of the research collection of some 1,700 strawberry plants managed by the UC Davis Public Strawberry Breeding Program. (Courtesy/UC Davis)
The jurors unanimously decided that Douglas Shaw and Kirk Larson willfully infringed UC patents, breached duties of loyalty and fiduciary duty and used plant material owned by the UC Davis Public Strawberry Breeding Program to develop berries for California Berry Cultivars, or CBC, a corporate breeding firm they established along with several large commercial nurseries and growers.
“This federal jury decision is good news for public strawberry breeding at UC Davis and all strawberry farmers throughout California and the world,” said Helene Dillard, dean of the UC Davis College of Agricultural and Environmental Sciences. “Our revitalized public strawberry breeding program will continue to develop affordable, high-quality varieties and train the next generation of breeders to serve every strawberry farmer, shipper, processor, and consumer.”
During the five-day trial, the jury heard evidence that Larson and Shaw — while still employed by the university — used both patented and unpatented strawberry breeding stock developed by generations of UC strawberry breeders to make crosses in Spain for their private company. Evidence showed they harvested the seeds from those UC varieties and unreleased plant material and sent them back to California to produce pedigree plants without the university’s knowledge or permission.
Shaw and Larson retired from the UC Davis Public Strawberry Breeding Program in 2014 after decades of successful breeding for the university, working with plant material they inherited from university breeders before them. Shaw and Larson sought a license from the university to use the UC varieties in their new business. The university ultimately decided not to grant a license to Shaw and Larson, but the evidence showed that Shaw, Larson and CBC decided to use university varieties and germplasm anyway.
Shaw, Larson and CBC filed a lawsuit against the University of California, charging the university with “breach of contract, conversion, breach of fiduciary duty, breach of implied covenant of good faith and fair dealing, and unfair competition” by attempting to patent the material rather than license it to CBC.
In a summary judgment decision issued in early May, District Judge Vince Chhabria threw out all but the claim of breach of good faith for the university’s decision to patent the plants. The jury ruled against that one CBC claim.
Especially important was testimony from Stephen Dellaporta, an expert in plant genetics at Yale University, who conducted DNA analysis for CBC plants grown in California from seeds imported from Spain.
“Ninety-nine percent of the genetic diversity of UC Davis patented varieties was captured by CBC’s breeding activity,” said Dellaporta, professor of molecular, cellular and developmental biology at Yale. “Also, CBC’s seedlings contain genetic material from five university-patented varieties that had not been released at the time they were bred, and 19 that had never been released.”
California is a leading producer of both fresh and processed strawberries, providing more than 87 percent of the strawberries consumed in North America. Strawberry varieties developed at UC Davis produce about 60 percent of the strawberries consumed worldwide and generate $2.5 billion a year.
California growers pay lower rates than other farmers for strawberries developed by the UC Davis Public Strawberry Breeding Program and get access to new varieties before growers elsewhere. Fees from licensing strawberry varieties go back to the program to support the research, training and innovation on which the industry relies.
“We appreciate the great varieties the university has produced over the years, and we look to what the future holds,” said Neil Nagata, a third-generation strawberry grower from San Diego County.
Professor Steve Knapp took over the UC Davis Public Strawberry Breeding Program in February 2015 and has several new varieties in the works, focusing on improved strawberry yield, flavor, shelf life, production efficiency and disease resistance.
The case is scheduled to return to court next Wednesday, May 31, when the judge will consider remedies that were not for the jury to decide.
Davis, Calif., (May 18, 2017) – Climate change will likely cause wheat and barley yields to decline by 17 to 33 percent by the end of the century, predicts a new statistical model developed by researchers at the University of California, Davis, and Cornell University.
The study, based on 65 years of weather records and wheat and barley yield data from France, provides some of the first evidence of the negative effects of warming on wheat and barley yields in Western Europe. The findings are reported online in the journal Environmental Research Letters.
The study is of particular importance because wheat is the most widely grown crop in the world and, along with rice, one of the top two sources of calories for human consumption.
“This is not to be interpreted as saying that yield will decrease regardless of any technological improvements that may be made in the future,” said co-author Matthew Gammans, a UC Davis graduate student working with Professor Pierre Mérel in the Department of Agricultural and Resource Economics.
“It does suggest, however, that climate change will lessen the rate of any yield improvements that will be achieved by technological advances,” Gammans said.
New statistical model for climate impacts
The new model, developed by Gammans, Mérel and Cornell economist Ariel Ortiz-Bobea, is one of the first flexible statistical models applied to wheat and other cereal crops. Model flexibility, allowing for extremely high or low temperatures to have very different effects than the average temperature, is important in understanding the true effects of temperatures on yields. This model was developed from data spanning 1950 to 2015.
The newly published study focused on three major crops: winter wheat, winter barley and spring barley, all of which are primarily watered by rainfall, rather than being irrigated. The winter crops are planted in the fall, lying dormant through the winter and then growing during spring and summer. Spring barley is planted in spring and grows through summer.
Key predictions
Based on the historical weather and yield data, the new model predicted that by the end of the century:
Yields are projected to decrease by 21 percent for winter wheat, 17.3 percent for winter barley and 33.6 percent for spring barley under the most severe warming scenario.
The negative impacts of increased heat during climate warming won’t be offset by a decrease in extreme cold temperatures during winter.
Possible increases in rainfall would help mitigate the effects of heat stress but would not be sufficient to offset the negative impacts of warming temperatures.
The model did predict that if technological improvements continue on their current trajectory, they could offset most of the negative effects of climate change. Such improvements could include new heat-tolerant crop varieties and improved farming methods.
“We now want to explore what role adaptation to climate change will play in mitigating negative impacts on yields of wheat, barley and other cereal grains,” Gammans said.
Agricultural data for this study was made available by the French Ministry of Agriculture.
