Posts Tagged: agricultural sustainability
When it comes to watering walnuts, most California growers believe you need to start early to keep trees healthy and productive throughout the long, hot summer. But according to striking results from a long-term experiment in a walnut orchard in Red Bluff, growers can improve crop production if they hold off irrigation until later in the season and directly measure their trees' water needs.
The findings from researchers at the University of California may help farmers optimize water use.
“It's a game-changer,” said walnut grower Hal Crain, who welcomed researchers on to his orchard to test irrigation optimization. “It's clear to me you can improve nut quality and yield by applying water based on what the tree wants and needs, rather than just watering when it's hot outside and the soil is dry. That's a big deal for walnut growers and for the entire agricultural industry.”
Changing the paradigm
Crain is a second-generation farmer whose family has been growing walnuts in Butte and Tehama counties for 55 years. Like most walnut farmers, Crain had always started irrigating in early to mid-May when the days grew warmer and the trees sprouted leaves.
“That's standard practice for probably 90 percent of California's walnut growers,” said Crain, walking amid his trees on a sunny afternoon. “The theory is that when you irrigate early, you preserve the deep moisture in the soil that trees need to survive the heat of summer.”
But that's not how it works, the research shows. Instead, trees that grow in saturated soil early in the season don't develop the deep roots they need to thrive.
“With all the water right there at the surface, the lower roots suffer,” explained Bruce Lampinen, UC Cooperative Extension orchard management specialist with the UC Davis Department of Plant Sciences. “Trees end up with a very shallow root system, which doesn't serve them well as they try to extract moisture from the soil later on.”
Lampinen has long suspected that walnuts were getting too much water in the spring.
“A lot of the symptoms we see like yellowing leaves and various diseases can all be explained by overwatering,” said Lampinen.
So Lampinen did what scientists do: He set up an experiment. Five years ago, with funding from the California Walnut Board and the U.S. Department of Agriculture, he joined forces with Ken Shackel, a plant sciences professor with UC Davis, and Allan Fulton, an irrigation adviser with UC Cooperative Extension. Together, they led a team of scientists testing irrigation on Crain's ranch.
“Hal is an exceptional partner,” Fulton said. “Farmers have a lot to accommodate when they host an experiment like this, with researchers going in and out of the orchard at all hours. He had to work around our people and the timing of our water treatments. He's always eager to experiment with technology and learn new things, and he shares what he learns with other growers. Hal completes the circle.”
Tough nut to crack
When is the best time to irrigate? Researchers say the trees hold the answer. Scientists use pressure chambers, which are air-pressure devices that measure a leaf or small shoot to gauge how hard the plant is working to pull moisture from the soil.
“Just because the soil looks dry doesn't mean the plant is suffering,” said Shackel, who specializes in plant physiology. “Pressure chambers let you ask the tree how it's feeling — sort of like taking a human's blood pressure — which is a much more accurate way to measure a plant's water needs.”
For the last five years, the team has been applying different water treatments to five blocks of trees. One block is getting standard, early irrigation. Crain's orchard managers begin irrigating the other blocks when the trees reach different levels of water stress based on pressure-chamber readings.
The trees that experience moderate stress are doing the best. Their irrigation usually starts in mid-to-late June, several weeks later than when standard watering begins.
“You can tell just by looking at that block that the trees are healthier,” said Crain, standing beneath a canopy of lush, green trees. “And, we're starting to see greater yields and better nut quality.”
Translating the research
The research is helping scientists advise farmers on irrigation.
“My biggest take-away is knowing when to start watering is a really important factor to the health of your trees,” Lampinen says.
Pressure chambers — sometimes called pressure bombs — can cost more than $3,000, and high-tech versions are under development.
“I tell growers a pressure bomb would pay for itself even if you just used it once a year to determine when to start watering,” Lampinen said.
Crain is certainly convinced.
“When you irrigate based on your trees' needs, you optimize water,” Crain says. “I'm not using less water overall, but the water I do use is producing more food. That's good news for everyone.”
This story was originally published in the Fall 2018 issue of Outlook Magazine, the alumni magazine for the UC Davis College of Agricultural and Environmental Sciences.
The new World Food Center at UC Davis will take on a broad purview related to food, including sustainable agricultural and environmental practices, food security and safety, hunger, poverty reduction through improved incomes, health and nutrition, population growth, new foods, genomics, food distribution systems, food waste, intellectual property distribution related to food, economic development and new technologies and policies.
With rapid global population growth occurring on smaller amounts of arable land, coupled with the expected impacts of climate change on food production, understanding the sustainability of food into the future is critical.
The new center’s website notes, “The World Food Center at UC Davis takes a ‘big picture’ approach to sustainably solving humanity’s most pressing problems in food and health. By bringing together world-class scientists with innovators, philanthropists and industry and public leaders, the center will generate the kind of visionary knowledge and practical policy solutions that will feed and nurture people for decades to come.”
In establishing the World Food Center, UC Davis Chancellor Linda Katehi said, “We did this to fully capitalize on our depth and expertise as the world’s leading university for education, research and scholarship on all aspects of food, but especially the nexus between food and health.”
UC Davis is the top-ranked agricultural university in the world, and California is the major producer of vegetables and fruit in the nation. Tom Tomich, director of the Agricultural Sustainability Institute and professor in the Department of Environmental Science and Policy at UC Davis, says of the World Food Center’s location at UC Davis, “There’s no place else that has the right mix of educational programs, research facilities, and the engagement with the state.”
The major academic disciplines surrounding food are found at UC Davis — agriculture, the environment, medicine, veterinary medicine, engineering, social and cultural sciences, and management. More than 30 centers and institutes at UC Davis will be pulled together through the World Food Center. The combination of scholarship, leadership, and partnerships at UC Davis has already established the campus as a center for food-related science and outreach. This new center will reinforce that strength and broaden the university’s ability to tackle tough global issues related to food.
Although the founding director of the center has yet to be named, Josette Lewis, Ph.D., was recently appointed as the associate director of the World Food Center. Her background on international research and development for the U.S. Agency for International Development, and director of its Office of Agriculture, honed her skills to take on the World Food Center. It was at US AID that she worked on a major global hunger and food security initiative, establishing her expertise on issues related to global agricultural development and food security.
As the new World Food Center becomes fully developed, it will be well-positioned on campus to continue to solve the major global issues related to food that are a hallmark of UC Davis.
- World Food Center website
- UC Davis video on the World Food Center
- Key facts
- UC Davis Dateline article
- Sacramento Bee article
The study found that wild bees were more abundant in diversified farming systems. Unlike large-scale monoculture agriculture, which typically relies upon pesticides and synthetic fertilizers, diversified farming systems promote ecological interactions that lead to sustainable, productive agriculture. Such systems are characterized by high levels of crop and vegetative diversity in agricultural fields and across farming landscapes.
“The way we manage our farms and agricultural landscapes is important for ensuring production of pollinated-food crops, which provide about one-third of our calories and far higher proportions of critical micronutrients,” said study senior author Claire Kremen, professor at the University of California, Berkeley’s Department of Environmental Science, Policy and Management. “This result provides strong support for the importance of biologically diversified, organic farming systems in ensuring sustainable food systems.”
Many of the study’s authors, including Kremen, also co-authored a study published March 1 in Science that found that fruit and vegetable production increased when wild pollinators – as opposed to domesticated honeybees – were more abundant.
“That study showed that wild bees helped crop yield, and this study shows that organic crops in a diversified farming system help wild bees,” said Kremen.
Christina Kennedy, senior scientist at The Nature Conservancy, is the study’s lead author.
- Wild Bees Are Good for Crops, But Crops Are Bad For Bees (NPR interview)
- Better Bees: Super Bees and Wild Bees (KQED Quest video)
- Wild bees make honey bees better pollinators (UC Berkeley press release)
The United States farm bill is up for renewal this year, and what goes into the $400 billion, 5,000-plus page piece of legislation will affect what tens of millions of Americans eat — and don’t eat — in the coming years. On April 5, UC Berkeley’s College of Natural Resources fired off an enlightening salvo in the public discourse, with a panel of heavy hitters calling on the public to let their voices be heard in the quest to, as panelist Karen Ross, Secretary of the California Department of Food and Agriculture, put it, “move farmers and eaters closer together.”
Looking at the bill’s history, it’s not surprising the two groups have been driven apart. The farm bill was implemented during the Great Depression in the 1930s in order to raise commodity prices and farmers’ incomes, said Gordon Rausser, UC Berkeley professor of agricultural and resource economics and the event’s moderator. The commodities it focused on — food grains, feed grains, dairy, tobacco and peanuts — became political powerhouses while much of the food on our dinner tables — fruits, vegetables, and nuts — were relegated to the category of “specialty crops.”
Broccoli and oranges … specialty crops? “That’s what we grow here in California,” Ross said. And that's what's on the U.S. Department of Agriculture’s food plate. In the past 15 years such growers have been taking a more active role in the farm bill to make sure they are not marginalized, she said.
Over eight decades the bill has morphed from a farm to a food bill, the panelists said. Seventy-seven percent of the bill now goes to support the federal Supplemental Nutritional Assistance Program (SNAP), the reinvention of the food stamps program.
Ken Hecht, just retired from his position as the director of the California Food Policy Advocates, reeled off some facts about the people who use SNAP:
- 50 percent are working households
- 93 percent are below the poverty level
- 50 percent of benefit recipients are children
- 75 percent are households with children
“There are 1.3 million children who are getting enough to eat because of this program,” Hecht said. “It avoids all those consequences of food insecurity that we all know about: lack of adequate nutrition, lack of adequate health, lack of academic opportunity and performance, lack of social development.” The program not only helps its participants, Hecht, said, but the rest of the people in the community as well.
In addition to SNAP, support for sustainable agriculture emerged as a theme of the presentation. For insight, In Defense of Food author and UC Berkeley journalism professor Michael Pollan offered the audience the perspective of a Martian: we Earthlings are now eating oil instead of eating sunlight. What he referred to as the “free lunch of photosynthesis” was swapped out, starting in the 1940s, for high-yield, industrialized farming that relies on pesticides, machines and giant feed-lots for animals. Pollan said that while farmers were enormously successful in achieving productivity goals, the environmental costs make agriculture second only to cars in fossil fuel production, and the producer of 20 to 30 percent of the country’s greenhouse gases. He recommends a simple criteria should be applied to every provision of the farm bill, from farmers market support to the SNAP program to obscure payment structures: “The question we should ask ourselves is, is this pushing agriculture back onto the sun or is it leaving it on the fossil fuel basis?” he said. “That’s the standard I think we need to apply.”
Environmental Working Group, framed the issue in terms of dollars. “One cotton farmer in 2004 received $2 million. That’s the same amount of money we spent for the entire federal program devoted to organic agricultural research,” he said.
He emphasized the connection between good food practices and good environmental practices, and called SNAP EWG’s number one priority. “We’re trying to inject healthy eating into the farm bill as a legitimate concern of public policy,” he said. He cited a pilot healthy-snack program, in which evaluators noted students who had never seen a pineapple or celery or carrots before. “We should be spending billions of dollars on this program ... getting kids hooked on fruits and vegetables."
Cook pointed out that that much of what drives the farm bill is the politics of committee members securing subsidies for their home states, and conjured the specter of the recent pink-slime debacle to show how effective a little activism can be. Fail to get involved at your peril, Cook, said. “I guarantee you will get more of the same or worse.”
Pollan passed along advice from one of Cook’s staffers: “Simply calling your representative and saying you want more healthy food, you want more environmentally sustainable food, is all you need to do.”
The event was a presentation of the UC Berkeley College of Natural Resource's Spring 2012 Horace Albright Lecture in Conservation. Watch an hour and a half video of the presentations and Q&A:
Food systems is a broad term that addresses nutrition and health, sustainable agriculture, and community development. A food system encompasses the entire production chain, not only from farm to fork, but includes broader topics such as short- and long-term impacts on the environment, labor, management of food inputs (e.g., water, pesticides) and outputs (e.g., waste), and the socioeconomic impacts on communities engaged in the food system. In other words, food systems encompasses agricultural production within the broad context of environmental, economic, social, and political concerns.
Neal Van Alfen, dean of the College of Agricultural and Environmental Sciences at UC Davis, noted during the celebration ceremony for the new major, “Agriculture is incredibly knowledge intensive. It is as knowledge intensive as launching rockets.” He cited a terrarium as a model for how we must maintain a sustainable food production system with limited resources to feed a rapidly growing global population. “The planet is a closed system,” Van Alfen said. “We have to get it right.”
Professor Tom Tomich, master adviser for the major and director of the UC Davis Agricultural Sustainability Institute, said, “The major is about leadership, as much as it is about education. It’s about creating a new generation of leaders who will go on to guide the sustainability transformation for this country and for this planet.” Unlike student programs that are limited to classroom learning, Tomich said that the curriculum for the new major combines the best of three worlds — classroom and labs, the Student Farm, and the real world.
Karen Ross, Secretary of the California Department of Food and Agriculture, attended the opening, along with other high-level state leaders in agriculture, including Craig McNamara, president of the California State Board of Food and Agriculture, and Don Bransford, president of the UC President’s Advisory Commission on Agriculture and Natural Resources.
UC Davis chancellor Linda Katehi, who spoke about UC Davis’s national leadership in sustainability, noted, “This leadership from the state shows the importance of the program and what impact it may have on the state, on us as an institution, and on our students.”
“Agriculture and food have shaped human civilization and are central to well-being and health,” said Ralph Hexter, provost of UC Davis. “We recognize the need to understand both the natural world and our human activities holistically.” Addressing the global significance of the major, Hexter added, “Sustainable Agriculture and Food Systems is a major that is truly designed for the 21st century. It responds to today’s needs and incorporates experiential learning and state-of-the-art research.”
A recent UC Davis graduate who helped lay the groundwork for the curriculum, Maggie Lickter, spoke passionately to the 200 people celebrating the major. She said that the major is driven largely by students who have cutting-edge ideas and want to be engaged in creating a useful education. Lickter said that many students felt that components were missing from the traditional agricultural curriculum, such as farming practices grounded in an understanding of ecological systems, and the application of critical thinking skills to modern-day food systems.
In a moving tribute to the success of establishing the major, Lickter said, “This work can’t stop. If you stop stoking romance, love dissolves. If you stop tending a garden, plants wither. So we must stay committed to the evolution of this major.”
Dean Van Alfen, a strong proponent of UC Davis partnerships with the California agriculture industry, views this major as an additional way to create graduates with industry-ready work skills. Addressing UC Davis’s national and global leadership in agriculture, he said, “Agricultural sustainability has been a theme of this campus for a very long time. This new interdisciplinary major is the future in so many ways. It reflects our campus spirit and our culture. It will meet the needs of our stakeholders and the future of our planet.”
For more information:
- UC Green Blog
- Early press release
- UC Davis Student Farm
- UC Davis Agricultural Sustainability Institute
- About the major