Posts Tagged: UC Davis
UCCE advisor Bruno guides, learns from dairies switching to milking robots
Automatic milking systems increasingly used in California amid labor challenges
When third-generation dairy farmer Shonda Reid first saw a milking robot at a farm show 13 years ago, she immediately recognized that the technology represented the future. Her father, however, took a bit more convincing.
“I came home and showed him and said, ‘This is what we need to do.' And he thought I was kidding!” said Reid, dairy and farm manager for Fred Rau Dairy, which has a herd of 1,400 milk cows in Fresno County.
Years later, after the family had visited several dairies using automatic milking systems (AMS) across the U.S., they installed their first six robots in November 2021. By fall 2022, they had 24 robots, evenly split between two newly built “free stall” barns where the cows can freely go to the milking machines.
As Fred Rau Dairy was one of the first in California to implement AMS at such a scale, Reid and her team have been instrumental in growing practical knowledge on these systems. She also has been a valued partner to Daniela Bruno, University of California Cooperative Extension dairy advisor for Fresno, Madera and Kings counties.
“Automatic milking robots are not a new technology, but it's new to California,” said Bruno, noting that the milking robots were first used on small, family-run farms in Europe, where the technology granted family members more time for rest and other pursuits.
To better understand the feasibility of milking robots for large dairies in California, Bruno – alongside former UC Davis School of Veterinary Medicine professor Fernanda Ferreira, University of Minnesota researcher Marcia Endres and other collaborators – began a project in 2020 to study the risks and opportunities of automated systems.
“The information is extremely useful for California producers to make informed decisions about implementing AMS on their facilities,” said Denise Mullinax, executive director of the California Dairy Research Foundation, which supported the effort through a competitive grant. “Cow care, labor requirements and profitability are key issues for producers, and CDRF was pleased to support this project which assists producers in understanding how AMS may impact those areas on their facility.”
Dairy farmer: ‘We needed to make some changes'
The project produced a paper analyzing existing research on automatic systems, which have been more widely used in the Midwest, where there are more small-scale, family-run dairies. In 2020, there were only 14 “box robots” in California, according to Bruno. Now there are about 200 across California – and both Bruno and Reid cited labor challenges as the primary reason for the increased use of automated systems.
“California suffers from labor quality and quantity issues,” Bruno said. “By bringing robots to California, you can minimize those problems.”
Higher costs of hiring and retaining employees, driven in part by new labor laws, are one factor. And then there's the reliability and availability of labor, as fewer people are willing to do the physically demanding work of conventional milking.
“People just don't want to milk in a flat barn [a conventional setup where the employee works at the same level as the cow] – there's a lot of kneeling, squatting, that type of thing – it's pretty tough on the body,” Reid explained.
Faced with labor shortages and mounting regulatory burdens, Reid said Fred Rau Dairy had to make the leap to automated systems to keep the 80-year-old dairy operation running.
“We needed to make some changes, or we're going out of the dairy business,” she said.
In a survey conducted by Bruno and her colleagues of large dairies using AMS across the U.S., a majority of the 29 respondents reported reductions in labor costs – but survey results did not offer a definitive picture on whether AMS improved bottom-line profitability.
Calmer, healthier cows
Nevertheless, most of the survey respondents said they were generally happy with their transition to automatic systems.
“It's totally met our expectations, and cow health has gotten much better, too,” Reid said.
In a typical conventional system where cows are outside in “open corral” pens, dairy employees must cajole the cows into the milking parlor. But within a “free stall” barn where the cows can voluntarily go to the milking robots when they want, as often as they want, the animals are much less stressed.
“When you think about cow handling, if you have robots, you don't have anybody pushing and screaming at them to walk to the parlor,” Bruno explained. “You have less cow-people interaction so they are more calm; there is less stress.”
In the survey of large dairies using milking robots, more than 90% of the respondents said their cows were calmer. Reid also noted that many people have noticed how calm their cows are in the free stall barns.
“They're not skittish, you can walk in and they don't run,” Reid said. “They'll just watch you or they'll even come up and start licking on your jacket or shirt.”
Bruno also said that many of the large dairies reported fewer cases of mastitis and other diseases, less lameness, and greater milk production. But she added it's hard to know whether the benefits can be attributed to the robots and their real-time monitoring technology – or to changes in the physical environment (cows save energy in the free stall barn setup, versus the open-corral system that requires walking to the milking parlor).
Dairy producers seek counsel on potential transition
Less bovine travel from outside to inside was a boon for Fred Rau Dairy during last year's unusually wet winter.
“Even if it's just a couple of weeks of rain, that mud and manure and everything – you do what you can, but oh my gosh – it's a mess,” said Reid, noting that easier facility maintenance during extreme weather was another benefit of switching to automatic systems within free stall barns.
Reid shared many of her experiences with attendees of an AMS Field Day in October 2022, arranged by Bruno, Ferreira and their collaborators. About 60 farmers, researchers, industry representatives and consultants visited Fred Rau Dairy and Jones Dairy in Merced County.
If a dairy producer is considering implementing automatic systems, Reid recommends that they research all their options, visit dairies that use the systems, and check who in their area would be providing service and technical support.
And there are crucial workforce considerations, as dairy workers must learn an entirely new set of skills and processes. Instead of spending their time fetching the cows, prepping them and milking them in the parlor, workers might need to gather and interpret data from the robots. “Cow people,” as Reid puts it, must become computer people.
“You have a group of people who have been with you for a while, and you hope that they can transition to the new technology of what you're doing,” Reid said.
During this technological transition, and on the myriad other challenges that dairy operators face, Reid said she is grateful for Bruno's expertise and responsiveness.
“If there's something that I need, she's been really good about trying to help – or putting me in contact with the right people,” she explained. “I've enjoyed working with her.”
The AMS project team also includes UC Davis School of Veterinary Medicine professor Fabio Lima, postdoctoral researcher Thaisa Marques and former postdoctoral researcher Camila Lage.
/h3>/h3>/h3>/h3>No-till annual wheat better for soil health in California’s climate
One more reason to adopt sustainable cultivation
California wheat farmers could both maintain their yields and improve soil health by growing annual wheat without tilling the soil year after year.
This could be one more encouragement to farmers to adopt a sustainable practice commonly called conservation tillage, no-till or minimum-till cultivation, impacting how we grow a grain that supplies about 20 percent of the calories and protein for people around the world.
A new study, by a team led by Mark Lundy, University of California Cooperative Extension specialist in UC Davis' Department of Plant Sciences, offers new insight for decades-long discussions around soil conservation, sustainable agriculture and climate-warming emissions related to growing our food. The study has been published in the journal Soil and Tillage Research. For the first time, researchers have shown that annual wheat that is not tilled each year is better for stashing carbon in the soil than perennial wheatgrass, while still yielding more crop in Central California.
Previous studies have looked at annual wheat that is tilled each year, annual wheat that is not tilled, and a cousin species, perennial intermediate wheatgrass (trademarked Kernza), which also is not tilled. But until now, no one has looked at all of the benefits and trade-offs together. Most importantly, “no one has ever controlled for tillage,” Lundy said. “And, no one has compared annual wheat to perennial intermediate wheatgrass over multiple years in a Mediterranean climate, which is what we have in California.”
This study also is unique because it delves into the deeper question of what is going on in the soil that drives the different results for carbon there. Soil carbon reflects various processes linked to plant activity and soil health. Measuring the different forms of soil carbon may also signal whether a farming system is accumulating carbon in the soil over time – a plus for reducing climate-warming gases in the atmosphere.
“Measuring soil carbon is complex and nuanced,” said Kalyn Taylor, the lead author on the paper. “We started this experiment because we wanted to know whether and how plant activity and tilling or not tilling would affect the carbon story belowground in California's climate.”
“When we started this study, we thought the crop being perennial or annual would drive the differences in carbon storage in the soil,” Lundy added. Specifically, they had expected perennial wheatgrass would lead to more carbon in the soil because of its deeper, better-established root system. “But that's not what we found,” he went on. “What we found was, it was the lack of tillage, plus the level of productivity of common annual wheat, that made the difference in soil carbon here in California.”
Soil carbon in annual vs. perennial grain
In 2017, Lundy, then-graduate-student Taylor, UC Davis Professor Emeritus Kate Scow and others on the team started measuring different forms of soil carbon in test plots at Russell Ranch, west of campus. Plots were planted with annual wheat that was tilled each spring, annual wheat that was not tilled and perennial intermediate wheatgrass (Kernza) that also was not tilled.
Each year, the researchers measured the carbon present in the soil, the amount of soil organisms (which have carbon in their bodies) and the amount of material the plants created.
At the end of three growing seasons, they found that land planted with no-till, common, annual wheat had the highest amount of soil organisms, measured as biomass, of the three treatments.
The researchers also found soil carbon is more likely to remain stable in the no-till, annual plots, compared to both tilled wheat and wheatgrass.
In addition, the no-till, annual wheat produced plant material more consistently than the perennial wheatgrass across the three years, which saw variation in rainfall.
“Overall, annual wheat grown without soil disturbance or tillage had both higher productivity and higher potential for storing carbon in the topsoil than perennial wheatgrass in our Mediterranean climate,” Lundy said.
Related research
“No-till annual wheat increases plant productivity, soil microbial biomass, and soil carbon stabilization relative to intermediate wheatgrass in a Mediterranean climate,” is online now and will be published in the January 2024 edition of Soil and Tillage Research.
The team also found that tilled annual wheat vs. Kernza stores total carbon at different depths in the soil profile and hosts distinct soil fungal communities, primarily in the root zone and topsoil: Taylor, K., Samaddar, S., Schmidt, R., Lundy, M. and Scow, K., 2023. Soil carbon storage and compositional responses of soil microbial communities under perennial grain IWG vs. annual wheat. Soil Biology and Biochemistry, p.109111.
Previous work comparing the perennial grain known as intermediate wheatgrass (trademarked Kernza) to annual wheat had not distinguished the extent to which soil health benefits are a function of the perennial nature of the crop. Read the story here.
This story was originally published on the UC Davis News site.
/h3>/h3>/h3>Reforms needed to expand prescribed burns
Study highlights 4 strategies to overcome barriers to prescribed fire in the West
Prescribed fire, which mimics natural fire regimes, can help improve forest health and reduce the likelihood of catastrophic wildfire. But this management tool is underused in the fire-prone U.S. West and Baja California, Mexico, due to several barriers.
A paper from the University of California, Davis, pinpoints those obstacles and suggests four key strategies that policymakers and land managers can take to get more “good fire” on the ground in North America's fire-adapted ecosystems. The paper also provides examples of how people are surmounting some of these obstacles.
“Prescribed fire is one of the most important tools we have for restoring natural fire regimes and undoing the effects of a century of fire suppression,” said lead author John Williams, a project scientist with the UC Davis Department of Environmental Science and Policy. “But there are a number top-down barriers at the upper levels of management that keep us from growing the workforce and getting burns done at the scale and extent needed. We point out some of the big ways that agency leaders and policymakers can dismantle those barriers and empower the full range of people capable of doing this work, from burn bosses and citizen-prescribed burn associations to nonprofits and tribal groups.”
The paper, published in the journal Frontiers in Ecology and the Environment, centers on the North American Mediterranean climate zone, which includes most of California, southwestern Oregon, western Nevada and northern Baja California in Mexico. Lenya Quinn-Davidson, director of UC Agriculture and Natural Resources' Fire Network, is a co-author of the paper.
A natural process
Fire is a natural process that has helped shape this region, but the area has experienced a spike in destructive, high-severity wildfires over the past decade. In fact, three of the five largest wildfires in continental U.S. history occurred in this region in just the past five years. This is due to a combination of climate change and fuel accumulation driven by a century of policies that encouraged fire suppression, curtailed Indigenous cultural burning, and favored harvest of the largest, most fire-tolerant trees, the study notes.
While scientists and resource managers recognize the need for more prescribed fire, its application has not kept pace with the enormity of the challenge. The study said that is because management policies prioritize fire suppression over prevention. There is also a limited fire workforce; regulatory hurdles like permitting, insurance and liability; and few incentives or protections for landowners, tribal members and other people who burn responsibly.
4 key strategies
Researchers identified four key areas where supportive institutional and agency leadership can help expand prescribed fire in the region:
1) Fire culture. After decades of emphasizing wildfire suppression, current fire management culture “does not adequately promote prescribed fire as a management tool,” the study said. Support for prescribed fire along the entire chain of command within agencies is needed to foster a new culture that incentivizes and enables prescribed fire practitioners within and outside of government agencies.
2) Funding. Prescribed fire is considerably more cost-effective than wildfire suppression, which can cost more than $2 billion a year in the U.S., but there is little dedicated funding for prescribed fire projects and lack of flexibility as to when such money can be spent. This impedes fire staffing and limits the kinds of projects that can be done. Year-round, dedicated funding and resources could help increase prescribed fire capacity.
3) Capacity building and cooperation. Connecting agencies with landowners, community members, tribes, prescribed burning associations (PBAs), prescribed fire training exchanges (TREXs) and others can facilitate responsible, effective prescribed fire and cultural burning exchanges. Such groups have limited reach and require investment and support to meet demand.
Inter-organizational agreements can also help local, state and federal agencies share resources and staffing. Formalizing and fully integrating such agreements into fire management plans remains a challenge, the study said. Collaborations that support Indigenous cultural burning are also key.
Partnerships must recognize the unique dimensions of cultural burning, which are inseparable from Indigenous culture. Educating land managers and decision makers about tribal sovereignty and federal American Indian law is critical. Introducing legislation that supports cultural burning can also foster such collaborations.
4) Monitoring and adaptive management. Designated funding and personnel for quantitative monitoring after a prescribed burn can help practitioners better measure success and then apply lessons to future burns.
“All of the barriers identified in the study can be overcome, and they have been at least partially resolved in other parts of the U.S., as well as in other Mediterranean climate regions, such as southwestern Australia,” said co-author Hugh Safford, a research ecologist in the UC Davis Department of Environmental Science and Policy and director of the California Prescribed Fire Monitoring Program. “Fundamental to setting the situation right is developing a culture of safe and regular fire use in California and neighboring states by all landowners and managers, and reducing the officiousness, risk aversion and bureaucracy that hinders access to the tool by the public.”
Additional co-authors include Ashley Grupenhoff and Beth Rose Middleton of UC Davis; Joe Restaino of CAL FIRE; Edward Smith of The Nature Conservancy; Chris Adlam of Oregon State University; and Hiram Rivera-Huerta of Autonomous University of Baja California, Mexico.
This research received financial support from the California Department of Forestry and Fire Protection (CAL FIRE).
This story was originally published on the UC Davis News site.
/h3>/h3>/h3>Researchers create app to help drones improve farm efficiency
When flown at the right times, drones can help farmers adapt to a changing climate
Researchers at the University of California, Davis, have developed a web application to help farmers and industry workers use drones and other uncrewed aerial vehicles, or UAVs, to generate the best possible data. By helping farmers use resources more efficiently, this advancement could help them adapt to a world with a changing climate that needs to feed billions.
Associate Professor Alireza Pourreza, director of the UC Davis Digital Agriculture Lab and postdoctoral researcher Hamid Jafarbiglu, who recently completed his doctorate in biological systems engineering under Pourreza, designed the When2Fly app to make drones more proficient and accurate. Specifically, the platform helps drone users avoid glare-like areas called hotspots that can ruin collected data.
Drone users select the date they plan to fly, the type of camera they are using and their location either by selecting a point on a map or by entering coordinates. The app then indicates the best times of that specific day to collect crop data from a drone.
Jafarbiglu and Pourreza, who is also a UC Cooperative Extension specialist of agricultural mechanization, said that using this app for drone imaging and data collection is crucial to improve farming efficiency and mitigate agriculture's carbon footprint. Receiving the best data — like what section of an orchard might need more nitrogen or less water, or what trees are being affected by disease — allows producers to allocate resources more efficiently and effectively.
"In conventional crop management, we manage the entire field uniformly assuming every single plant will produce a uniform amount of yield, and they require a uniform amount of input, which is not an accurate assumption," said Pourreza. "We need to have an insight into our crops' spatial variability to be able to identify and address issues timely and precisely, and drones are these amazing tools that are accessible to growers, but they need to know how to use them properly."
Dispelling the solar noon belief
In 2019, Jafarbiglu was working to extract data from aerial images of walnut and almond orchards and other specialty crops when he realized something was wrong with the data.
"No matter how accurately we calibrated all the data, we were still not getting good results," said Jafarbiglu. "I took this to Alireza, and I said, 'I feel there's something extra in the data that we are not aware of and that we're not compensating for.' I decided to check it all."
Jafarbiglu pored through the 100 terabytes of images collected over three years. He noticed that after the images had been calibrated, there were glaring bright white spots where they were supposed to look flat and uniform.
But it couldn't be a glare because the sun was behind the drone taking the image. So Jafarbiglu reviewed literature going back to the 1980s in search of other examples of this phenomenon. Not only did he find mentions of it, but also that researchers had coined a term for it: hotspot.
A hotspot happens when the sun and UAV are lined up in such a way that the drone is between the viewable area of the camera's lens system and the sun. The drone takes photos of the Earth, and the resulting images have a gradual increase in brightness toward a certain area. That bright point is the hotspot.
The hotspots are a problem, Jafarbiglu said, because when collecting UAV data in agriculture, where a high level of overlap is required, observed differences in the calibrated images need to come solely from plant differences.
For example, every plant may appear in 20 or more images, each from varying view angles. In some images, the plant might be close to the hotspot, while in others it may be situated further away, so the reflectance may vary based on the plant's distance from the hotspot and spatial location in the frame, not based on any of the plant's inherent properties. If all these images are combined into a mosaic and data are extracted, the reliability of the data would be compromised, rendering it useless.
Pourreza and Jafarbiglu found that the hotspots consistently occurred when drones were taking images at solar noon in mid-summer, which many believe is the best time to fly drones. It's an obvious assumption: the sun is at its highest point above the Earth, variations in illumination are minimal, if not steady and fewer shadows are visible in the images. However, sometimes that works against the drone because the sun's geometrical relationship to the Earth varies based on location and the time of year, increasing the chance of having a hotspot inside the image frame when the sun is higher in the sky.
"In high-latitude regions such as Canada, you don't have any problem; you can fly anytime. But then in low-latitude regions such as California, you will have a little bit of a problem because of the sun angle," Pourreza said. "Then as you get closer to the equator, the problem gets bigger and bigger. For example, the best time of flight in Northern California and Southern California will be different. Then you go to summer in Guatemala, and basically, from 10:30 a.m. to almost 2 p.m. you shouldn't fly, depending on the field-oriented control of the camera. It's exactly the opposite of the conventional belief, that everywhere we should fly at solar noon."
Grow technology, nourish the planet
Drones are not the only tools that can make use of this discovery, which was funded by the AI Institute for Next Generation Food Systems. Troy Magney, an assistant professor of plant sciences at UC Davis, mainly uses towers to scan fields and collect plant reflectance data from various viewing angles. He contacted Jafarbiglu after reading his research, published in February in the ISPRS Journal of Photogrammetry and Remote Sensing, because he was seeing a similar issue in the remote sensing of plants and noted that it's often ignored by end users.
"The work that Hamid and Ali have done will be beneficial to a wide range of researchers, both at the tower and the drone scale, and help them to interpret what they are actually seeing, whether it's a change in vegetation or a change in just the angular impact of the signal," he said.
For Pourreza, the When2Fly app represents a major step forward in deploying technology to solve challenges in agriculture, including the ultimate conundrum: feeding a growing population with limited resources.
"California is much more advanced than other states and other countries with technology, but still our agriculture in the Central Valley uses technologies from 30 to 40 years ago," said Pourreza. "My research is focused on sensing, but there are other areas like 5G connectivity and cloud computing to automate the data collection and analytics process and make it real-time. All this data can help growers make informed decisions that can lead to an efficient food production system. When2Fly is an important element of that."
This article was originally published on the UC Davis College of Engineering News page.
/h3>/h3>/h3>Nearly 70% of private label avocado oil rancid or mixed with other oils
Researchers identify key markers to help professional retail buyers choose authentic products
Avocado oil has become a popular choice for many people in recent years because of its heart-healthy benefits and versatility in cooking. However, not all avocado oil products on store shelves are created equal. Some products are labeled as “pure” avocado oil when they contain other oils or additives. No enforceable standards defining the chemical and physical characteristics of avocado oil exist yet.
Researchers at the University of California, Davis, analyzed samples of 36 private label avocado oil products and graded them based on quality and purity. Private label products are made by a third-party processor and sold under a grocery store or retailer brand label. Their findings, published in the journal Food Control, show that 31% of the samples tested were pure, and 36% were of advertised quality. Quality refers to whether the oil is fresh or has gone bad due to aging, heat or light exposure. For purity, researchers measured fatty acids, sterols and other components that differentiate avocado oil from other oils.
The study included oils purchased from 19 retailers in the U.S. and Canada with various price points. They found that lower-priced oils were more likely to be tainted with other oils.
“We found that low-cost products indicate a higher probability for adulteration, but high cost didn't guarantee purity or quality,” said Selina Wang, associate professor of Cooperative Extension in the Department of Food Science and Technology. She and Hilary Green, a postdoctoral researcher at UC Davis, co-authored the paper.
Researchers also identified certain chemical markers in avocado oil that professional retail buyers can use to make more informed decisions when it comes to choosing suppliers. This way, consumers can feel confident about the products they buy.
This is the second comprehensive study conducted by UC Davis researchers on the quality of avocado oil sold in the U.S. The first study released in 2020 found that many of the test samples were of poor quality, mislabeled or adulterated with other oils.
“This study demonstrates that although progress is being made in standard development since our first market study in 2020, there are still issues with purity in avocado oil and these issues extend significantly into private label oils,” Wang said.
Avocado oil standards
Since the release of the first UC Davis study, Wang said there's been a coordinated effort by researchers, industry leaders and government agencies to establish enforceable standards. The Avocado Oil Expert Group was formed in collaboration with the American Oil Chemists' Society to discuss potential standards and future research projects.
Wang's research group has been studying how natural factors like different types of avocados, harvest times, geographic origins and processing methods could affect the chemical composition of avocado oil. They want to create standards that will accommodate natural variations while detecting any adulterations.
Wang hopes that the study's findings will contribute to the establishment of standards that benefit both consumers and avocado oil producers who want to compete in a fair market.
“I'm very optimistic for the future of the avocado oil industry,” Wang said. “It's a high-value product with high consumer demand, similar to what I saw with olive oil 10 years ago. Olive oil quality and purity have improved significantly, which is where I see avocado oil going, if we can establish fair standards and eliminate fraudulent products.”
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