- Author: Michael Hsu
In 20-year study, UCCE specialist Mitchell, colleagues, growers advance no-till and cover cropping practices
In the 1990s, long before “regenerative agriculture” was a buzzword and “soil health” became a cause célèbre, a young graduate student named Jeff Mitchell first learned about similar concepts during an agronomy meeting in the Deep South.
Mitchell was astonished to hear a long list of benefits attributed to practices known internationally as “conservation agriculture” – eliminating or reducing tillage, cover cropping and preserving surface residues (the plant debris left after harvest). Potential positive impacts include decreasing dust in the air, saving farmers money on fuel and equipment maintenance, improving soil vitality and water dynamics and a host of other ecosystem services.
“All of these things start adding up and you kind of scratch your head and say, ‘Well, maybe we ought to try some of this,'” recalled Mitchell, who became a University of California Cooperative Extension cropping systems specialist at UC Davis in 1994.
In 1998, Mitchell launched a long-term study of those practices at the West Side Research and Extension Center (REC) in Five Points, Fresno County. “We started this because, way back when I first began my job, nobody was doing this,” he explained. “This was brand-new, uncharted territory for California.”
For the next 20 years, Mitchell and his colleagues studied changes to the soil and ecosystem, learned from their failures and successes, and shared those hard-won lessons with fellow scientists and farmers across the state. A summary of their findings was recently published in the journal California Agriculture.
Conservation agriculture in California: ‘No trivial undertaking'
Mitchell and the Conservation Agriculture Systems Innovation Workgroup – a network established in 1998 comprising farmers, researchers, public agency personnel and members of private entities and environmental groups – started with a virtually blank slate. According to Mitchell, surveys at the beginning of the 21st century found that conservation agriculture practices were used on less than one-half of 1% of annual crop acreage in California.
Although no-till is common in the Midwest and Southeast of the U.S. and across wide swaths of the globe, it was almost unheard of in the Golden State. With the development of irrigation infrastructure in the 1920s, California farmers saw continually phenomenal growth in yield over the last century – and thus had little incentive to deviate from tried-and-true methods that relied on regular tillage.
Nevertheless, intrigued by the potential benefits of conservation agriculture, Mitchell wanted to see which of those practices could be feasibly applied to California cropping systems. During the 20-year study at West Side REC, the researchers grew a rotation of cotton-tomato, followed by a rotation of garbanzo, melons, and sorghum, and finally tomatoes.
But at first, it was a struggle to grow anything at all – as they had to master the basics of how to establish the plants in a no-till, high-residue system.
“This was no trivial undertaking,” Mitchell said. “Early on we struggled – we failed the first couple of years because we didn't know the planting techniques and we had to learn those. There was an upfront, very steep learning curve that we had to manage and overcome.”
Then there was the long wait to see any measurable improvements to soil health indicators, such as the amount carbon in the soil.
“For the first eight years, we didn't see any changes whatsoever,” Mitchell said. “But then they became strikingly different, between the no-till cover crop system and the conventional field without cover crops, and the divergence between those two systems became even starker.”
The two-decade time horizon for the West Side REC study is one major reason why it has been so valuable for growers and scientists alike.
“It's so hard to capture measurable changes in soil health and soil function metrics through research because those changes are really slow,” said Sarah Light, UCCE agronomy farm advisor for Sutter, Yuba and Colusa counties and a co-author of the recent California Agriculture paper. “Often in the course of a three-year grant you don't actually get statistically significant differences.”
Reaching, teaching and learning from farmers
The study site on the west side of the San Joaquin Valley also has been a vital teaching resource. Even though Light works with farmers in the Sacramento Valley, she has conveyed findings from that research with her clientele and uses soil samples from the site to vividly illustrate a significant benefit of conservation agriculture practices.
In one demonstration, she drops soil aggregates – which look like clumps of soil – into two containers of water. One clump, from heavily tilled land, falls apart quickly and the water becomes dark and murky. The other, comprised of soil that has been no-till and cover cropped for 20 years, holds together – a sign of healthy, resilient soil – and the water remains relatively clear.
“It's a really simple demo, but it's very effective because it shows how easily soil aggregates break apart with water – or not,” Light said.
That aggregate stability is a key factor in soil's ability to both move water (infiltration) and hold onto water (retention). Those dynamics are crucial for farmers to avoid ponding in their fields, preserve water for drier months, and generally endure the flood/drought whiplash of climate change.
Over the years, Mitchell has hosted thousands of visitors at the West Side REC study site to showcase the potential benefits of adopting soil-health management practices.
“I don't think I'm exaggerating in saying that this is probably the most-visited agricultural field station project in the history of UC ANR (UC Agriculture and Natural Resources),” he said.
Both the West Side REC – and Mitchell himself – are greatly valued by the local grower community.
“Jeff is a microcosm of the university's applied research on the West Side of the San Joaquin Valley,” said John Diener, who grows almonds, fresh market garlic, canning tomatoes, cotton, masa corn and wheat for production and seed on land adjacent to the field station.
Growers adopt, adapt and adjust practices
Tom Willey, a retired farmer and longtime collaborator with Mitchell, has actively encouraged peers to visit the Five Points site – especially in the early years.
“It was very innovative and there weren't many examples of that anywhere in the state,” Willey said. “So, I helped encourage people to go out there and learn and possibly think about doing similar work on their own farms.”
Willey himself was a pioneer in experimenting with no-till practices in organic vegetable cropping systems.
“As organic farmers, we were probably more tillage dependent than conventional farmers because it was the only method we had for weed control; we weren't able to use herbicides,” Willey said.
Despite early struggles, he persisted in trying different techniques and mechanical means of weeding. And Willey later partnered with a group of progressive vegetable growers and UC and California State University Chico personnel to secure a Conservation Innovation Grant from the Natural Resources Conservation Service to support more on-farm trials and share their experiences.
In the end, however, no-till proved too risky to continue, given the losses they incurred. One tricky issue is nutrient cycling. The organic growers found that after mowing down a cover crop and spreading compost, leaving those nutrients on the surface without incorporating into the soil through more vigorous tilling (or adding synthetic fertilizers, as conventional growers could do) results in lower yields. In the short term, farmers simply did not see yields that could sustain their operation.
“It's very difficult in vegetable systems, and particularly difficult in organic vegetable systems,” Willey said. “I would say a number of us have learned to diminish the over-reliance that we had on tillage, but not to completely eliminate it.”
Cover cropping is also a challenge for some farmers, with certain cover crops making a perfect haven for devastating pests such as lygus bugs and stink bugs, according to Diener.
“We do everything we can to eliminate the host crop from which they come, so why am I going to bring the enemies to my house?” he said. “It's about making enough money to be there next year. You're not going to be there next year with these pests. It's just not a practical management option, in light of our significant pest pressure and disease hosts for our crops of value.”
Instead of planting cover crops, Diener said he opts for mixing in grain crops that can similarly contribute to soil health – while generating revenue at the same time. According to Diener, a longtime collaborator with Mitchell, the best way to adopt conservation agriculture practices is to tailor them to specific localities and each grower's circumstances. And in his corner of the San Joaquin Valley, that means not following the template of the high-precipitation, no-till systems found in the Midwest.
“We've adapted Jeff's principles to our program; it won't look like Iowa to you, which is what everybody comes to expect to see. It ain't how it works, folks,” Diener said. “It's a different methodology. We do those things that fit our environment and that's why that West Side field station is important – because it's our environment.”
Promoting and enhancing soil health, one step at a time
More widespread adoption of soil-health management practices can be driven by a variety of factors. With the rise of drip irrigation in tomatoes, for example, more growers began using no-till or reduced till to minimize disruptions to the delicate driptape in their fields.
And, according to Mitchell, the dramatic increase in no-till practices in dairy silage production – from less than 1% to over 40% – was the result of entrepreneurial efforts by a small but extraordinarily dedicated group from the private sector that worked with farmers, one by one.
Because optimizing these practices requires close and intensive attention – and no small amount of courage and gumption – Mitchell and Light understand that growers might need to take an incremental approach. Even one fewer pass over the field, or cover cropping every other year, can provide some benefit for soil health, Light said.
“The value is that when you can prove the concept, then you can motivate every step of the way,” Light explained. “Jeff is showing the shining light of the goalposts, and that can motivate us to take every challenging step along the way.”
Shannon Cappellazzi, who helped with the data analysis on the recently published California Agriculture paper, agrees that there is value in taking a stepwise approach in building soil health.
Cappellazzi was the lead project scientist on the Soil Health Institute's North American Project to Evaluate Soil Health Measurements, which looked at 124 different long-term soil research sites across the continent – including the Five Points site.
After analyzing 2,000 samples from the various study sites, Cappellazzi said the evidence suggests that layering on each component of a conservation agriculture program – doing no-till, adding cover crops and then integrating livestock, for example – can have additive, cumulative benefits for soil health.
“I think having the data to show the long-term benefit makes people willing to do the short-term change, even if it's a little bit hard for a couple years,” Cappellazzi said.
The research at the West Side REC also produced another key takeaway.
“To me, what really stood out was that for most of the soil health indicators, cover crops had a huge impact. Both the cover crops that had no till – and the cover crops that had standard tillage – had considerably higher carbon and soil health indicator measurements than those without cover crops,” said Cappellazzi. She added that the data also indicated improvements in how the water moved into the soil, and how the soil held that water.
Vital research drives an enduring legacy
Water management and conservation, of course, will be paramount in California's increasingly volatile climate reality. Mitchell's Five Points research – and related studies across the San Joaquin Valley by UC Davis agroecologist Amélie Gaudin and others – contributed data that overturned a long-held belief about winter cover cropping.
“There's a lot of preconceived ideas about cover crop water use,” Mitchell said. “One of the things that we learned was that compared to bare soil water loss in the wintertime, cover crop water loss during that same growing period – from about November through March – tends to be almost a wash.”
That crucial finding provided researchers and soil health advocates with invaluable evidence to preserve the practice as an option for farmers.
“They've needed to go around and give a dog-and-pony show to a lot of Groundwater Sustainability Agencies (GSA) that had been on the brink of banning the growing of cover crops because the perception out there is that they use a lot of water,” said Willey, the retired vegetable grower. “But over the winter months, cover crops don't use a lot of water. In fact, they may not use any net water at all.”
The young researchers who studied cover-crop water use represent another important legacy of the Five Points study site. It has been an experiential training ground for many of the next generation of soil scientists, agronomists and ecologists.
“The number of students who have been trained by and through this study has been really phenomenal,” said Mitchell, noting that they have worked on topics ranging from air quality to soil carbon related to no-till and cover cropping.
Their contributions will be essential in continuing to refine and optimize these practices that are fundamental to conservation agriculture. On Diener's concerns about lygus bugs and stink bugs, for example, Cappellazzi – in her new role as director of research at GO Seed – is studying and breeding cover crops with an eye on characteristics that make for less hospitable habitats for certain pests.
Indeed, while the California Agriculture paper effectively wraps up the 20-year study at Five Points, its lessons will continue to resonate and inspire for years to come.
“This is a step in a long journey,” Light said. “It's a launchpad – this paper might be able to tie a bow on it in terms of the data collection, but in terms of the extension impact, this is really just the beginning.”
And for Willey, the omnipresent climate crisis compels the entire sector to pick up the pace along that journey.
“We've got a lot of pressure now to evolve agriculture very rapidly in response to climate change and I don't think we can sit around and twiddle our thumbs,” he said. “We know the directions we need to be heading – with more natural systems mimicry and less reliance on toxic inputs and synthetic fertilizers – and we need to figure out how to incentivize and support farmers in moving in those directions.”
/h3>/h3>/h3>/h3>/h3>/h3>- Author: Deanne Meyer
Last week was a world wind tour of three Research and Extension Centers (RECs). Oranges, cotton and sorghum were not yet harvested at our South Valley RECs. Darren Haver, Maru Fernandez and I had great visits at these RECs. It was thrilling to hear about the various research projects and how UC ANR and campus faculty are finding ways to improve California agriculture.
Jasmine Del Toro (Business Officer), Don Cleek(superintendent) and Ashraf El Kereamy (Director) shared activity at Lindcove from research projects to how the processing/packing shed works. We were just a few weeks before harvest begins so we imagined the packing shed in full swing. Citrus of all types, from kumquats to pomelos and Buddha's hand, are grown at Lindcove. There's even a project on reuse of ground trees as mulch. This year's fruit is not yet harvested and already blossoms were on trees continuing the cycle. Maru spent quality time with Jasmin to help through new financial record keeping requirements. Much better than doing it over zoom.
Buddha's hand, Lindcove Pistachio tree, West Side Greenhouse, Kearney
At West Side we met with Karen Motly (Business Officer), Brian Neufeld (superintendent) and Tom Turini (Interim Director). Tom discussed center history and needs. Brian gave us a top-notch tour of the REC. Karen worked with Maru and Darren. It was exciting to see pistachios still on the tree. We were able to pick them and realize how soft the shell is while the nut is on the tree. If you're used to almond hulls, pistachios don't have that amount of external cover.
Wednesday we toured Kearney. There's much activity with detailed alfalfa work, organic plots, trees (fruit, nut, novel), vines, hemp, etc. Also, there is IR-4 work. Scientists from University of California campuses (Davis, Riverside and Berkeley) make Kearney their home. It was great to meet our newest Cooperative Extension Specialist Jackie Atim as well as see exciting work done by others.
All three RECs work to address issues growers face related to nitrogen management, water conservation and integrated pest management. It's fabulous to have land available for controlled experiments, greenhouses, and areas to isolate plants and pests. These facilities provide researchers from all over California with unique opportunities. Thank you to all the staff who keep the RECs running.
An exciting part of the week was a Zoom meet and greet with many Community Nutrition and Health Advisors, Amira Resnick and many new colleagues at UC San Francisco. The combined group spent focused on community-based research and outreach programs to improve health. This is the first of many interactions. The groups had so much in common.
Human Resources and many search committees have been busy! We welcome student assistants Taylor Baisey and Sia'h Jimissa (NPI), Cedric Renaudin (NFCS), Amritpal Kaur (Kern), Yolanda Tabarez (Desert REC); agricultural technician, Jovani Renteria, Lindcove; Lab helper, Tyler Waltrip; Blank Assistants Shayna Blythe (BOC), Katherine Fessler (State 4-H office), Robin Martin (Central Sierra MCP) and Andrea Rayray (SWPR). Rounding out our new hires were Joaquin Vega (Facilities, Planning and Management), Uriel Gonzalez (IT Services) and Benjamin Saltzman (IGIS Programmer). Three more Advisors joined our ranks too: Stephanie Mar, Organic Waste, South Coast REC; Joanna Solins, Environmental Horticulture, Capitol Corridor MCP, Yu-Chen Wang, Plant Pathology, Santa Cruz.
It takes many people to keep UC ANR running! Thank you for your contributions.
- Author: Wendy Powers
Last week flew by. Tu, David, and I spent a day at the South Coast REC talking about a new building project and envisioning a new educational center that could draw in the local community and serve as a central spot at the REC for researchers to convene and brainstorm. Then we spent the next day at Desert REC doing the same. The excitement of constructing a new facility was evident in both Jairo and Stacy. Let's all help them harness that enthusiasm to push through the hassles that come with construction. Both RECs are in need of the facilities and their programs will grow as a result.
The Orange County Farm Bureau (OCFB) has agreed to support a 5-year gift proposal at SCREC and UCCE Orange County in the amount of $690,000 paid out over a period of five-years (pledge), commencing in April 2023 and concluding in April 2027. A large portion of the funds are current-use funds to support the GROW program at SCREC. The balance of funds supports the Forever 4-H endowment in Orange County and the local 4-H program. Congratulations to Darren and team, Scott Brayton, and Mary Ciricillo for the work on securing this gift!
Anne Iaccopucci and Katherine Soule are busy these days preparing for a 4-H Academy on Youth Mental Health coming up May 10 - 12. Their colleagues from around the country have made special note of their contributions. Congratulations also go out to JoLynn for her garden project work with a local juvenile detention facility that became a feature story for My Motherlode. Way to go JoLynn!
I returned to the Oakland office last week, for the first time since February 2020. We moved up a floor – part of the fire drill fitness plan, I suspect. It was a great feeling to be back in that building. I was a bit surprised to see how many people on the street were still wearing masks. Better safe than sorry. I elected to avoid the BART and bear the traffic instead. It was a long drive home. It seems the roads are full again. I believe my trip to Davis on Friday was perhaps the heaviest traffic I have ever seen at 5 AM and then again at 5 PM. I don't know what to make of this.
Merit and promotion packages are almost complete with first review. Following, I go back and read supervisor comments, external reviewer comments, and internal reviewer comments from ad hoc reviewers and the Peer Review Committee. I always learn more about the work and impact of UC ANR as I read through the packages. The number of packages with strong impact statements continues to grow; particularly from some of our recent hires!
Word is out of my pending departure. A tremendously difficult decision to make as I don't feel that my work here is done. The change is a growth opportunity, one I couldn't pass by. In the meantime, there are many more ANR Adventures to be had.
- Author: Wendy Powers
It drizzled a bit this morning! What a welcomed occurrence, though I hope it is sunny for the visit to the Lindcove REC on Friday. Despite the rain, the thought of fire is never far away. Take a look at this new report from UC, including our very own Faith Kearns and the California Institute for Water Resources. Congratulations, Faith, on this effort! In particular, I like the policy focus of the report.
The South Coast REC crew have a few minutes of fame for their longstanding program success. The Voice of OC recently talked about just some of the farming activity that goes on at the REC. Take a look. Congratulations to Jason, Tammy, and the entire team that keep agriculture front and center despite urbanization of the area!
Earlier this week I had a chance to meet with the AAC-Personnel Committee. That group certainly stays busy. I enjoyed the conversation and the follow up discussions since that have largely centered on ensuring success for our expanding workforce.
The hiring continues! Since last post, I believe we have filled one or two additional CE Advisor positions (up to 4 now, I believe) plus a new CE Specialist position. This is all very exciting. Equally exciting is the list I received of National Association of County Agriculture Agents awardees. Newer UC ANR academics are among some of our awardees. Congratulations to Brooke Latack who received a national award for a featured story, Apurba Barman who placed as a national finalist for a fact sheet, Sonia Rios who received an early career achievement award and was a Western Region Finalist in the newsletter competition and the photo competition, Zheng Wang who was a Western Region Finalist for the event promotion competition and the website/online competition, and Michael Rethwisch who was a Western Region Finalist in the computer generated presentation with transcript competition and received one of the competitive spots to make a national presentation. Special thanks to Zheng Wang for service as the Western regional vice-chair of the Recognition and Awards Committee!
The deadline to submit position proposals is fast approaching. After I return from the Lindcove Citrus Tasting and tour with UCCE Tulare County, I will be checking email for CE Specialist position proposals from our campuses. Program Council met yesterday and has a process outlined to review and deliberate each submission. It has been hard work for those submitting proposals and will be hard work for Program Council and the Vice President to make decisions. But, work well worthwhile, considering this is what we have wanted for a long time. Imagine how exciting it will be to have more colleagues across the state!
On that note, time for a rest before the work resumes.
- Author: Wendy Powers
This week I am attending the virtual APLU (Association of Public and Land Grant Universities) meeting. This is one of those meetings that should always be virtual. For some reason, they spread the meeting over a 2-week period this year. Let's just say that didn't improve my opinion of the meeting. And to make things worse, every session has a unique Zoom ID and I don't have them in my calendar. I suspect participation may be down this year. I will miss Wednesday's sessions to attend jury duty. Who knew I would welcome a summons?
Other activities include preparing to repost a Vice Provost position, some prep work for next week's meetings, and planning for the December Program Council meeting. I know many continue to work hard on Advisor and Specialist position descriptions that are due in less than a month. Time sure does fly by! It seems impossible to think that next week is Thanksgiving already. This means that Giving Tuesday is right around the corner. Speaking with Scott today, it sounds like the giving has started early. It is always nice to hear such things.
There's much going on at the RECs this time of year. Ashraf and team are busy preparing for the Citrus Tasting at Lindcove. To add to the planning this year, the President's Advisory Commission (PAC) are holding their winter meeting during the tasting. Karmjot and her team will be sharing some of their efforts with the PAC. It's a busy time for Hopland as well. Take a look at all that John and team have been doing. It's great to see local coverage of the efforts! The projects at Hopland REC continue to grow.
Later this week, I have a chance to meet with some of our newer hires that opt to participate in office hours. And, the monthly Town Hall is Thursday, which is always a chance to hear what's on the minds of people across UC ANR. I have a number of meetings related to national Extension commitments as well. The schedule feels a bit lighter this week because there is no travel to schedule around.
I have procrastinated on the weeds for a couple of months now, but likely must get into the yard this weekend. The rain has been great and while perhaps insufficient for addressing the drought, my weeds flourish. Perhaps if I ever get ahead of the weeds, I will expand my hobbies. Somehow I doubt I will have the same level of artistic talent displayed by others who teach themselves to draw when they can't sleep.