Posts Tagged: Jeff Mitchell
Healthy soil does much more than hold plants upright on the surface of the earth. It is a mix of mineral bits and old plant particles teeming with microbes to form a mysterious and complex web of life scientists are just beginning to understand.
While scientists use high technology to study heathy soil – painstakingly counting soil worms and bugs, sequencing the DNA of soil bacteria, for example – some farmers know intuitively whether the soil is healthy just by walking on it.
Scott Park is a first-generation Meridian, Calif., farmer. “When I step on a field and it feels like a road, something is wrong,” he said. “If it feels like a marshmallow or sponge, that's good.”
Park shared his farming experiences with 200 farmers, industry representatives, University of California Cooperative Extension scientists, Fresno State students, news media and others during a half-day UC workshop at the UC West Side Research and Extension Center in Five Points.
“The last 31 years I've been on a mission of building soil,” Park said. “I discovered it by accident and I've made lots of mistakes. But yields trend upwards every year on every crop. Being sensitive to building soil, I'm making a lot of money. And if I'm doing something for the earth, all the better.”
Park said he adds 10 to 15 tons per acre of biomass to his farm every year. He's using less fertilizer, up to 20 percent less water, and even experimenting on the farm by growing a commercial crop with just four inputs: cover crops, water, seed and sun.
“We got high-yielding, good-quality crops,” Park said. “Nobody was more shocked than I am that I got a good crop.”
Researchers are now using the scientific method to figure out the root causes of these empirical observations.
“There's a lot going on in soil,” said Radomir Schmidt, a UC Davis soil microbiologist who spoke at the soil health field day.
A teaspoon of soil has a billion bacteria and six miles of fungal hyphae, the filaments that branch out through the soil from fungi, Schmidt said. The microbes' interaction with living plant roots, the larger pores left by decomposing vegetation and tunneling worms and insects create a system that confers resilience to unforeseen challenges – such as pest pressure, torrential rainfall and plant diseases.
The field day was held under a tent pitched adjacent to an 18-year research trial at the 320-acre facility. The trial compares four farming systems side by side:
- Conventional system, with annual soil tillage and no cover crops.
- Conservation agriculture, with no tilling whatsoever and annual winter cover crops.
- No-till without the cover crop.
- Conventional tilling with a cover crop.
“Take a look over my shoulder to see the difference,” said Jeff Mitchell, UC Cooperative Extension specialist and the study leader. “We've found the cover crops and no-till reduce water needs, cut dust, and lower costs. And there may be more benefits than we realized.”
For example, a graduate student counted the worms, bugs, beetles and other microfauna in soil samples from each of the treatments. There were double the amount in the no-till, cover crop plots compared to the conventional farming system.
UC Cooperative Extension specialist Sloan Rice found that cover crops promote water retention in the soil after rainfall. There is very little water evaporation from the soil surface and water transportation from the cover crop plants in the winter, so little water is lost. Cover crops also promote more water infiltration below three feet.
Healthy soil management also shows promise in confronting global climate change by sequestering carbon in the soil, rather than depleting it.
Manager of Sano Farms in Firebaugh, Jesse Sanchez, was a speaker at the field day. He wasn't surprised by the overflow crowd.
“Farmers are more and more curious. They see some of us using cover crops, and they want to learn more,” Sanchez said. “There has been a swell of interest. I have a tremendous number of visitors every year.”
For more information about soil building, see the UC Conservation Agriculture Systems Innovation website at http://casi.ucanr.edu.
Record winter rainfall during the 2016-17 winter has enabled farms to emerge from survival mode in the short term, but scientists are still working hard to be ready for the next drought, reported Tim Hearden in Capital Press.
Hearden spent a day at the UC Kearney Agricultural Research and Extension Center in Parlier to learn how researchers at the facility and the UC West Side Research and Extension Center near Five Points are combining technology with management practices to put every drop of irrigation water to work.
“This is one of the few places in the world where you can do drought research on a field level,” said Jeff Dahlberg, director of the 330-acre Kearney facility. “What I'm planning is a world-class drought nursery.”
At the West Side REC, researchers are working with farmers to perfect micro-irrigation efficiency and test drought stress on the area's most prevalent crops.
“We'll grow a tremendous number of cultivars of a crop” and identify “what seem to be the most promising cultivars when you grow them under drought conditions,” said Bob Hutmacher, a cotton specialist and the center's director.
Hearden spoke to Jeff Mitchell, UCCE cropping systems specialist and director of the Conservation Agriculture Systems Innovation center (CASI). CASI is encouraging farmers to adopt farming practices that save water, reduce dust and help improve the condition of soil, such as subsurface drip irrigation, overhead irrigation, minimum tillage, cover crops and crop residues.
“This is not done right now in California,” Mitchell said. “In the future, there may be a strong likelihood of certain agricultural sectors adopting these practices.”
Other subsurface irrigation trials are showing dramatic increases in yields. Khaled Bali, an irrigation water management specialist at Kearney, said underground drip systems in alfalfa fields have achieved 20 to 30 percent more yields while in some cases using 20 percent less water.
Kevin Day, a UCCE pomology advisor in Tulare County, is trying subsurface drip in a peach and nectarine orchard after working with the USDA to use it for pomegranates. He's seen as much as a 90 percent reduction in weeds because there's no surface water to feed them.
“Fewer weeds, fewer pesticides,” he said. “We use high-frequency irrigation. We irrigate as the crop needs it. When you do that, you keep the roots deeper, which makes for better aeration.”
Improved soil promises to help farmers use less water and reduce carbon in the atmosphere, reported Ezra David Romero on Valley Edition, a one-hour weekly program that airs on KVPR-FM.
The five-minute story, which begins at the 30:30 mark, focuses on CDFA's new Healthy Soils Initiative. The program is expected to allocate $7.5 million for farmer incentives to use practices that will improve soil health and reduce greenhouse gas emissions. These are practices that are already in place on some innovative valley farmers, including two that are active in the UC Agriculture and Natural Resources' Conservation Agriculture Systems Innovation center.
Jesse Sanchez, manager at Sano Farms in Firebaugh, said 15 years ago, tractors were rolling across the 4,000-acre tomato farm all the time. Now, the farm features cover crops in the winter, reduced soil tillage, irrigation with super-efficient buried drip tape and lower fertilizer needs. The result is a one-third drop in water use and a 75 percent reduction in diesel to fuel tractors, Romero said.
Many of the farm's tractors have been sold. "We don't want to see them no more," Sanchez said.
Retired Madera County farmer Tom Willey discussed the critical importance of soil care he learned as a long-time organic vegetable grower.
"It's the survival of our species," Willey said. "The soil is the thin skin of the earth that we all exist on. Our lives are bound up in the health and productivity of the soil."
UC Cooperative Extension specialist Jeff Mitchell noted the challenges that farmers face in making soil care changes. “A real part of the challenge for California farms is the high-value nature of the production systems, the crops themselves, and some difficult challenges in terms of the diversity of the crops," he said.
How do you cut your water use by a third, cut your nitrogen use in half, maintain your tomato yield and improve your fruit quality?
“With patience, perseverance and by treating your soil like a living ecosystem — which it is,” says Jesse Sanchez.
Sanchez should know. He and Alan Sano have been experimenting with soil enhancements for 15 years on Sano Farms in Firebaugh. They believe they have hit upon a winning strategy — though their experiments continue.
Today, they grow 50-ton-per-acre tomatoes with half of the nitrogen (120 units) and a third less water than before. They also report fewer weeds and better tomato quality.
The soil organic matter (SOM) — the living portion of the soil that turns crop residue into minerals needed by growing plants — has gone from 0.5 percent to 3.0 percent, report Sano and Sanchez.
“The soil is like day and night,” says Sanchez. “You can dig it with your hands,” he says, cupping a handful to prove his point.
So how do you transition largely inert soil into the ecological powerhouse found on Sano Farms?
Cover crops, reduced equipment passes, and subsurface irrigation have been key, according to Jeff Mitchell, UC Cooperative Extension specialist based at the UC Kearney Agricultural Research and Extension Center. These practices combine to feed and protect the soil microorganisms often ignored in agricultural systems. Mitchell has been coaching the Sano/Sanchez team for over 10 years, witnessing their progress and connecting them with like-minded farmers and organizations.
“Farmers sometimes worry that cover crops will compete with the cash crop for water and nutrients,” says Mitchell. “We're starting to see at Sano Farms — looking long term — that the tradeoffs might actually be favorable.”
Sanchez says he terminates the cover crop before the tomatoes are planted, leaving the dead residue to smother weeds and feed the soil microorganisms.
The SOM also builds the sponge that allows the farm to thrive on less water, says Zahangir Kabir, soil health specialist with USDA's Natural Resources Conservation Service.
“A one percent increase in SOM builds your soil's ability to hold water by 19,000 to 25,000 gallons per acre. Calculating conservatively, Sano Farms' fields hold 50,000 gallons of water more per acre than they did before," Kabir said.
You can see this in action at Sano farms. “When it rains here the water soaks into the field. It stays put,” says Sanchez. “It doesn't run off like some farms.”
Sanchez, who received a White House Champions of Change Award last summer, says he knows farmers resist change. “But we can't stop change,” he says. “It's all around us.”
And, if they (farmers) do change the way they work with their soil, says Sanchez, “they are going to like what they see. ”
Sanchez will be a featured speaker at the second annual Latino Farmers Conference on Nov. 15 at the Monterey Hyatt Regency. The event is free but registration is required. http://www.nrcs.usda.gov/wps/portal/nrcs/events/ca/newsroom/events/?eventid=584#584 .
USDA NRCS produced a three-minute video profile of Alan Sano and Jesse Sanchez at Sano Farms in Firebaugh. View it here:
Jeff Mitchell, UC Cooperative Extension agronomy specialist.
A series of farm visits this summer in the Central Valley prove this rationale wrong, Mitchell said. The farm visits were sponsored by the UC Conservation Agriculture Systems Innovation Center (CASI), USDA's Natural Resources Conservation Service and the California Association of Resource Conservation Districts. The farm visits showcased the soil health goals and experiences of six farmers who are familiar with soil care principles across a wide range of local cropping contexts.
The series of visits demonstrated the use of no-till and minimum tillage farming, cover cropping, enhancing the diversity of above-ground species and underground soil biology, surface residue preservation, and compost applications.
John Teixeira is a diversified farmer in Firebaugh working to develop integrated crop and livestock systems that are not reliant on external inputs. Pursuing a diverse rotation that includes alfalfa, cover crops, and a variety of heirloom grain crops that are marketed as both raw seed and value-added pasta, Teixeira is working to enhance soil function and fertility so that all external impacts are eliminated.
Michael Crowell and his son Adam grow silage crops near their Turlock dairy and dryland small grain crops using no tillage along Highway 4 in the rolling hills south of Dixon. They use no-till as a means to reduce soil water evaporation and to increase the water holding capacity of their soil, thereby enabling them to produce economically viable crops on the region's typical 14 inches of winter rainfall.
Darrell Cordova and his son Trevor of Denair also use no-tillage for their summer silage corn and winter small grain forage mixes and as a means for stabilizing the soil, adding surface residues, increasing infiltration and reducing runoff under their center pivot-irrigated crops growing on undulating terrain. These practices also cut costs and eliminate considerable labor.
Tom Willey of Madera uses compost applications ahead of each of his organic vegetable crops to build the nutrient-provision and water-holding capacities of his soils. His sustained dedication to these amendment applications and his farming goal of attempting to mimic natural systems in terms of active, high-functioning soil biology enable him to produce a great diversity of very high quality vegetables.
Alan Sano and Jesse Sanchez in Firebaugh have combined the conservation ag/soil care practices of reduced disturbance and cover crops for more than 10 years in their processing tomato fields. They report lower costs, improved soil tilth, and the ability to reduce nitrogen fertilizer inputs by about half.
“These six soil care farmers share an uncommon dedication to the principles that are at the core of soil health and conservation agriculture systems,” Mitchell said. “Each of them reported tangible value that they are receiving from their attention to caring for the soil and working to improve soil function.”
Mitchell and the network of organizations that are part of CASI now seek a new wave of farmers who are interested in evaluating conservation agriculture, climate-smart practices at their farms.
For information on how to become involved with farm performance monitoring and the educational activities, see the CASI website at http://casi.ucanr.edu/