Posts Tagged: organic
“The goal of our study is to provide organic farmers with science-based strategies that effectively limit food-safety risks when using raw manure-based soil amendments,” said Alda Pires, UC Cooperative Extension urban agriculture and food safety specialist in the School of Veterinary Medicine at UC Davis.
To study the survival of pathogens in soil and soil health, UC scientists are recruiting California growers who use raw or untreated manure in organically grown crop fields.
Pires is leading the project in California with Michele Jay-Russell, a veterinary research microbiologist and manager at the Western Center for Food Safety at UC Davis.
The researchers will visit participating farms eight times over the 2017-2018 growing season.
“We will collect produce, water, soil and manure samples,” said Jay-Russell. “All of the samples will be tested for bacterial indicators such as nonpathogenic E. coli and pathogens. We will ask the farmers to complete a short survey. The study is voluntary and all locations and names will be kept confidential.”
Eligible California farms must be certified as organic by the National Organic Program or California Certified Organic Farmers and fertilize with raw manure or untreated manure from dairy cattle, horses or poultry. The farms can grow any of the following produce: lettuce, spinach, carrots, radishes, tomatoes or cucumbers.
This study is being conducted in other states by the University of Minnesota, University of Maine, USDA Agricultural Research Service's Beltsville Agricultural Center, USDA Economic Research Service's Resource and Rural Economics Division, Cornell University and The Organic Center. The project is funded by a U.S. Department of Agriculture Organic Research and Extension Initiative grant.
One of the events that attendees could sign up for was lunch with a scientist at The Ohio State University, located a few miles away from the conference venue. I chose Prof. Jeffrey LeJeune, an infectious disease microbiologist and epidemiologist, because a focus of his research is food safety, one of the topics included in the UC Global Food Initiative that UC President Janet Napolitano launched on July 1.
On the day of the luncheon, a Sunday, we were driven to The Ohio State University in buses the university provided. We assembled in the lobby of the Ohio Union (it was homecoming on campus and the Columbus marathon was in progress nearby), and were soon escorted to the tables of the scientists we had picked. The university kindly (and safely!) provided lunch.
At LeJeune's table, we introduced ourselves to one another. LeJeune began his presentation to his 15 guests by rebuffing the five-second rule. According to this rule, food dropped on the ground will not become contaminated with bacteria if it is picked up within five seconds of being dropped. LeJeune said it does not work. “Eating off the floor violates all food-borne illness prevention advice,” he warned.
Perhaps because we in his audience were all science writers, he proceeded to discuss communication challenges facing scientists. He said most of the emphasis in graduate training is on making discoveries, with hardly any attention paid to communicating these discoveries in lay language to benefit the general public. Other challenges he mentioned are the information explosion we are witnessing, resulting in deaf ears turned to many scientists' voices; and language barriers between scientists and journalists that hinder effective communication.
“The pasteurization of milk was a huge benefit to the health of the human population,” he said. “Most cheeses in the U.S. are pasteurized cheese products.”
We asked him many questions. He answered them all. He explained that the U.S. has the safest food supply. Despite this, pathogens can enter the food chain through live animals, he cautioned. Further, refrigeration could be inadequate. He said about 80 percent of food and vegetable contamination occurs post-farm. His tip for what to eat when traveling: “Avoid raw or unpeeled foods. It is best to choose what is fully cooked and hot.”
LeJeune noted there is no evidence to suggest that GM foods are problematic from a food safety perspective.
“There are some concerns for sure,” he said. “But these are largely economic or political. Nutrition-wise, GM foods can be beneficial. From a food safety and nutritional standpoint, I also see no significant differences between organic produce and non-organic or regular produce. There could be, however, some environmental impacts related to the different production systems.”
More questions followed. A discussion on E. coli bacteria gathered momentum, specifically how E. coli gets infected with a virus and how, when this virus decides to leave E. coli, it releases Shiga toxins, which, in turn, damage cells lining the kidney.
We were so engrossed in the discussion that it came as a surprise when one of the organizers of the luncheon strode into the room to inform us that our hour with the scientist was up and that the bus that had transported us to The Ohio State University was about to leave.
As we rose hastily from our chairs we thanked LeJeune for his presentation, which was clear and to the point – qualities all science (and other) writers appreciate. We know he had other topics to discuss with us: Can I cook my Jack-o'-Lantern after Halloween? (The answer is “Not if it sits out for more than two hours.”) And are raw diets for dogs a public health concern for humans? (The answer is “Your dog is more likely to have Salmonella if it is eating raw food.)
Although we didn't get to these topics, he left us with ample useful information about food safety. On the ride back to the conference, the bus was loud with conversation from the various lunch groups – what had been learned, how best it could be communicated, and how each one of us had made a new friend at the university.
At the same time, chefs and food buyers at universities, particularly the University of California, are selecting for high-quality fruits and vegetables, produced locally and sustainably. Universities with strong food sustainability programs are rightfully proud of what they're doing to educate students about food production, health, and nutrition. UC Davis Dining Services prioritizes the purchase of locally grown food (ideally within a 50-mile radius of campus). Most University of California campuses have similar programs.
At UC Davis, fresh roma tomatoes are picked each August from the 300-acre Russell Ranch, part of the campus's Agricultural Sustainability Institute, then processed within hours by campus Dining Services to provide year-round tomato sauce for pizza, pasta, and ratatouille. All told, 10,000 pounds of tomatoes are processed during a two-week period in August. About 29 percent of the total food served in the campus's residential dining halls is from local, organic or sustainable sources.
Emma Torbert, an academic coordinator at the UC Davis Agricultural Sustainability Institute, noted, “Connecting the food system to the research is really interesting. A lot of times there is confusion about where our food is coming from. The more people are educated, the more educated decisions they can make.”
Many UC Davis faculty and staff are so impressed with the food choices at the dorms that they purchase individual meal tickets and enjoy lunches made with the campus-grown tomatoes, herbs, and other vegetables, all of which are part of the daily food array. Public dinners are also offered periodically at the dorms so that community members can sit amongst students to taste and learn about the sustainability programs in the dorms.
- Video: Farm to Table, UC Davis Tomatoes; 2010
- Slide show of this year's UC Davis tomato harvesting and processing system; 2014
- Sustainable Foodservice Progress Report 2014, UC Davis Dining Services
- Two videos of UC Davis students who work at the Student Farm to produce food, including one on tomato sauce production
- “Tomatoes: Safe methods to store, preserve, and enjoy.” UC Agriculture and Natural Resources, free publication
Adapted from an article by Eileen Ecklund in Breakthroughs magazine.
But a group of UC Berkeley scientists say that continuing on our current path of industrial agriculture is simply not sustainable, given its enormous water, energy and chemical inputs, together with the new challenges posed by climate change, such as temperature and precipitation extremes.
With the launch of the interdisciplinary Berkeley Center Diversified Farming Systems late last year, UC Berkeley scientists are coalescing around a set of biodiversity-promoting farming practices they say are a promising solution.
Claire Kremen, a conservation biologist and associate professor in the Department of Environmental Science, Policy and Management, says that most or even all of the inputs that modern commercial farms require — chemical pesticides and fertilizers, wasteful amounts of water and energy, imported pollinators — were needed only because the monoculture-dominated landscapes created by industrial agriculture lacked biodiversity.
"From studying the pollinators, I realized that the way we conduct agriculture has basically required us to replace all of the ecosystem services that used to be in the agricultural ecosystem with substitutes," said Kremen, a 2007 MacArthur Fellow.
Generally speaking, a diversified farming system is one that promotes biodiversity across spatial scales, from plot to field to landscape. Crops are planted and livestock raised in combination, resulting in interactions that sponsor the functioning of the farming systems in ways that replenish natural ecosystems. Methods employed within a diversified farm may include minimal soil tillage, growing multiple crops together, planting cover crops, and interspersing trees and shrubs with crops and livestock.
These practices also provide pollination, pest and disease control, water purification, and erosion control. They help to build healthy, productive soil and reduce water use, as demonstrated by research conducted by Kremen and her Berkeley colleague Miguel Altieri in their respective labs and on farms in Napa, Sonoma, and Yolo counties.
But diversified farming systems aren't just about providing food and protecting the environment; to be truly sustainable, they must also provide a livelihood to farmers and farm laborers, and help support the communities that depend on them. UC Berkeley-based Cooperative Extension specialist Christy Getz has studied farm labor conditions and food security among agricultural workers. In one project, her team developed a program to help Southeast Asian refugee farmers in California scale up their operations, connect to alternative distribution systems, and access new markets for their produce, such as local schools.
Professor Alistair Isles focuses on the public policy, science policy, and sociological dimensions of making a switch back to diversified systems from industrial agriculture in developed countries. For example, he has studied the importance of innovative consumer tools that promote sustainable agriculture such issues as "food miles"—the distance that food travels from farm to table—and sustainable seafood evaluation methods.
If farmers could bring back many of the traditional practices that supported biodiversity, enhanced by the application of modern ecological science, Kremen believes that the world could produce more food while reducing agriculture's harmful effects, making it more sustainable over the long term.
And unlike organic agriculture, diversified farming systems are not an all-or-nothing approach; Kremen says farmers can implements all the systems the Berkeley center recommends based on its research, or simply implement selected techniques, such as planting native-plant hedgerows or using soil-enriching cover crops, and still make their farms more sustainable.
My calendar says November but the weeds in my garden think it’s spring. That nice rain last month followed by warm, sunny days has prompted them to grow like, well, weeds and that’s not good news for my winter crops.
What’s a gardener to do?
Like so many other gardeners, I turned to the folks at the UC Davis Weed Science Program. Housed in the UC Davis Department of Plant Sciences, the “weeders” are experts at helping growers and gardeners improve plant production by controlling weeds.
Which tools work the best in which situations? Here’s a quick overview, courtesy of Cooperative Extension Specialist Tom Lanini, who specializes in weed control in vegetable crops.
Mulches – Researchers test them all – plastic, bark, wood chips, other porous material, even what they call live mulches like clovers and fava beans. Mulches block light, which weeds need to grow. “I think mulches can be the best organic option for fighting weeds, especially for vines and trees,” Lanini says. Mulches are also a key weed-fighting component in organic strawberry and many other crops.
Organic sprays – Coverage is the key. “No matter what type you use – oils, soaps, acids, etc. – if you don’t spray-to-wet, 100 percent coverage, the weeds will grow back,” Lanini says. Temperature and the age of the weed matters too. Apply in temperatures above 75 degrees when weeds are very young – about a week old – for best results. Broadleaf weeds are easier than grasses to control with sprays.
The most effective organic spray Lanini has found so far is good old-fashioned vinegar, the kind you use to make pickles. The trouble with that is, the FDA has yet to approve it for controlling weeds. “You can eat it, but can’t spray it on your weeds,” as Lanini says. There are herbicides with vinegar as their active ingredient, but they are much more costly than household vinegar.
Flamers – These propane-fueled devices quickly raise the temperature of the weed to more than 130 degrees, rupturing its cell membranes. Grasses are hard to kill by flaming because the growing point is protected underground. Flamers require quite a bit of fuel, which can be costly.
Solarization has become an important method of weed and disease control in organic desert vegetable crops. In this system, four to six weeks of solar heat under clear plastic film will kill weed seeds and pathogen propagules.
Cultural practices are extremely important in all vegetable crops especially in organic crops. Crop rotations result in shifting environments that do not favor any one weed. Use of preplant irrigation followed by shallow tillage, or flaming is a very effective method of reducing the potential weed infestation during the crop cycle.
Weeding and thinning by tool or machine is a time-honored solution. Never underestimate the value of a hoe.
For more detail on weed management for organic vegetable crops, Click here.