- Author: Amanda Charles
Amanda Charles comes to us from Petaluma, CA as a new member of the Community Education Specialist team. She represents the Sonoma County region at the UCCE Sonoma office in assisting growers with the application and implementation processes of CDFA's Climate Smart Ag Funding Programs – AMMP, HSP, SWEEP. Charles earned her bachelor's degree in Agricultural Business at Cal Poly San Luis Obispo where she took a special interest in Dairy Science courses, furthering her love and knowledge for the industry. Upon returning home, she began working for a sustainable grass-fed beef company where she educated consumers about the positive impact farming practices can have in sequestering carbon and mitigating the issues of climate change.
Charles' involvement in local agriculture began as a child, exhibiting dairy cattle and market lambs in 4-H. She knew she wanted to return to Sonoma County to expand on her passion for sustainable agriculture in her community. “Helping farmers understand how switching up their farming practices can better their soil and our atmosphere, and then letting them know that there is funding available for these new practices is the best of both worlds” said Charles. She is looking forward to collaborating with more local coalitions to support farmers and ranchers in the fight against climate change.
/span>- Author: sashroder@ucdavis.edu
Cover crops can provide many soil and ecosystem benefits, like improving water infiltration and providing resources for pollinators. However, we don't yet know which cover crop species are best suited for specific cash crops.
To answer this, I planted potatoes into the residue of 5 cover crop mixes in Shafter (Kern County). Here are the mixes I planted:
1. Soil health mix: Merced rye, common vetch, berseem clover, and daikon radish
2. Soil builder mix: triticale, Dundale peas, common vetch, yellow mustard, and radish
3. Brassica pollinator mix: yellow mustard, daikon radish, Nemfix mustard, “Bracco” white mustard, and canola
4. Simple mix 1: Merced rye and Dundale peas
5. Simple mix 2: barley and common vetch
I wanted to see if the cover crops would reduce disease incidence or improve yield. Here's what I did in this trial:
Potatoes were harvested on August 3, 2021. |
So, what did we see? We had a few challenges:
Southern blight and other soil borne pathogens
By June 9, all of the rows had some potato plants, but it was very patchy. |
The plants were dying because they were infected with southern blight and other soil borne pathogens (right photo). |
Results
So, did we find anything interesting?
There was too much variability and not enough replication to see meaningful differences in the yields associated with the different cover crop mixes.
Further research is needed to identify the best cover crop species for each cash crop in Kern County.
Key takeaways
Southern blight thrives under the conditions of the trial field in Shafter. It has historically only been a major problem in Kern County, but other areas of California are now reporting cases due to warming temperatures.
It grows best under these conditions:
- Warm temperatures
- Acidic soil – the soil pH in the top 6 inches of soil was between 5.8 and 6.3
- Decaying organic matter – in this case, the decomposing cover crops
- High soil moisture – we used sprinkler irrigation
Unfortunately, southern blight doesn't just attack potatoes. It has a wide range of hosts and can decimate other vegetable crops like tomatoes, cucumbers, and chard.
Should I not plant cover crops because of southern blight?
The potato trial in the neighboring field was also decimated by southern blight. That field was fallow before the potatoes were planted, with no cover crops.
If you plan to grow a crop that is susceptible to southern blight and you are in Kern County, you should focus on the cultural practices and chemical products that will reduce your risk of crop loss.
If you plant cover crops, make sure that the crop residue has completely decomposed before planting your cash crop. This might require terminating your cover crops early, so that there is enough time for complete decomposition.
In this trial, there was an incredible amount of biomass left over from the cover crops. They were irrigated and planted at 1.8X the recommended seeding rate. There was also plenty of nitrogen and warm weather to fuel their growth. If your cover crops do not produce as much biomass, especially ligneous biomass, then they should not take as long to break down as the ones in this study did.
More information about southern blight
- https://content.ces.ncsu.edu/southern-blight-of-vegetable-crops
- http://ccvegcrops.ucanr.edu/newsletters/Tomato_Info_Newsletters72607.pdf
For more information about the trial, contact Shulamit Shroder at sashroder@ucanr.edu or 661-903-9442.
Many thanks to Jed Dubose, Jaspreet Sidhu, Jennifer Fernberg, Cristal Hernandez, Brian Marsh, Rick Ramirez, Caddie Bergren, and Samikshya Budhathoki for their help.
/table>/table>
- Author: Dana Yount
Daniel Unruh, and his family, farm just under 200 acres of walnuts alongside the Sacramento River, just outside of Princeton, CA. The walnut orchard is irrigated with solid set sprinklers and is only irrigated when needed, or if there is not enough rain during the season. Daniel started cover cropping in 2013 with the main goal of nematode suppression, and soon after, he and his wife took over the orchard operations. The cover crops that show up now between rows is voluntary, as he has not spread seed in years, but still sees a successful cover. He also practices reduced till on his farm to encourage the cover crop growth and help increase biomass production.
Daniel has not received money from any grants, or other outside funding sources to establish cover crops, this was just something he saw benefit in after the first few years of nematode reduction. His passion for cover cropping has grown to encompass more than just nematode suppression however, and he is now seeing plenty of benefits elsewhere around his orchard.
Beneficials of all kinds consider his orchard a home, less water is running off of his property during storms and irrigation, and he has cut his input and commercial fertilizer bill down by close to 75%. The soil organic matter for his orchard has also increased from around 1.7-1.9% to 3.0% when tested in 2020. When Daniel and his wife first took over in 2014, the orchard was sprayed for husk fly, coddling moth and blight, but now only blight has been addressed in recent years. In fact, he has not used any fertilizer at all the past few years, but has seen a slight reduction in yield as a result. Daniel also has seen changes in his irrigation cycle in what used to be a rotation of every 7-10 days, has been extended to every 12-14 days due to moisture retention.
Like many other farmers, his main concerns with cover cropping in an orchard system was termination, and the learning curve that comes along with it. Daniel was even able to design a roller crimper, with chevron crimps, specifically for his operation and the type of cover crops he uses for termination. His cover crop stand consists of brassicas, grasses and legumes and can easily grow to over 6 feet tall. When he originally planted, Daniel spread seed 17 feet across for almost 90% coverage. His roller crimper helps lay plant material down to protect the soil from the sun, improve water retention and creates an environment beneficial to microorganisms.
Daniel is so passionate about improving his soil microbiology and reducing his inputs, he even serves as a Mentor Farmer at the Chico State Center for Regenerative Agriculture. Daniel has presented at numerous events and has hosted workshops at his orchard to educate and encourage other growers to give soil management practices a try. Daniel says he is never done learning, and attends many workshops throughout the year as well.
Finally, Daniel encourages a holistic outlook, and motivates others to keep trying various approaches if it doesn't work the first time until you find a system that does work for your operation. He goes on to say you should try alternatives first before going straight to spraying fertilizer as eventually plants will rely on this synthetic ‘health' and it will not last.More on Daniel and how he has contributed to this research can be found at https://www.csuchico.edu/regenerativeagriculture/demos/daniel-unruh.shtml
- Author: Samikshya Budhathoki
- Author: Caddie Bergren
Steven Cardoza farms 300 acres of organic raisin grapes with his father in Fresno County, California. He met with us recently to share his experiences with cover cropping and more broadly, his transition towards regenerative agriculture.
Steven remembers falling asleep as a kid on their tractor and following around his dad, who began farming before Steven was born, and has been certified organic for over 22 years. Steven joined the family business full-time six years ago and hasn't looked back.
Even though they were certified organic, they suffered from weed and pest pressure. Steven was introduced to the idea of ‘regenerative agriculture' and was intrigued, so he began learning as much as he could on his own. He estimates he has listened to thousands of hours of podcasts about agriculture while sitting on his tractor, and said it really came to life when he could see right in front of him what the podcasts were talking about.
Experience with cover crops
Cardoza made two significant changes from what his father had been doing. First, he began cover cropping every row instead of every other row, and second, he leaves the crop without mowing as long as possible, often as late as August. He has experimented with various cover crop seed mixes and blends, and continues to see what works best. “Nature does not like to be naked, and I want to keep living plants on the ground as much as possible”, says Cardoza.
Now that he cover crops all his vineyards, he has not seen a pest outbreak in the past two years. He also has not applied any nitrogen fertilizer at all, although sometimes he does use compost. He is most excited to experiment with cover crops' ability to suppress weeds, something that is a high priority for organic farmers with few herbicide options. Through trial and error, he is finding that barley has been reseeding along the berms of his rows and slowly outcompeting the Johnson grass. In some blocks, he has estimated a 98% reduction in Johnson grass in the past few years.
Through the CDFA Healthy Soils Demonstration Project program, he has received a grant in collaboration with the UC Coop extension in Fresno to experiment further with his cover crops. He is excited to try out a mower that ejects the mowed cover crops right onto the berms on each side of the row, further suppressing weeds near his vines.
A Central Valley question: But what about water use?
Most of Cardoza's vineyard blocks are drip-irrigated. This means that the cover crops, which are planted in between the rows of his vines, are not irrigated at all. He waits until the first rain in the fall/winter to plant. Some years are better than others, but he says he has always been happy with how they have grown. We were able to tour one block of vineyard that has the ability for flood irrigation. The cover crops were much taller, greener, and healthier looking than in the drip-irrigated sections. However, they have not been irrigated all winter; Cardoza does one post-harvest flood irrigation, plants his cover crops directly afterwards and lets them grow with only nature's inputs after that.
Advice for other growers?
“Get comfortable with being uncomfortable,” he says. He spends a lot of time thinking about and experimenting with his cover crops and other regenerative practices. He also says he's getting the local reputation of “the cover crop guy”, and other growers have called him with questions such as how to calibrate a drill seeder. He says the trend in some of the older generation of farmers was to closely guard your secrets to success from your neighbors and he'd like that to change. “I've spent a lot of time and effort to learn what I have, and I'm very happy to share it with other farmers who want to make similar changes”. When he sees another farmer successfully implementing regenerative practices, he knows it's not just benefiting their bottom line, but their land as well, and that makes him feel good.
Learn about Steven Cardoza in the video link below who is implementing innovative farming practices to improve the soil health of his vineyard!
- Author: Dana Yount
- Contributor: Kristian M Salgado
- Contributor: Emily Lovell
- Contributor: Caddie Bergren
- View More...
UC ANR Climate Smart Agriculture Educator team assisted growers to win CDFA grants that reduced greenhouse gases equivalent to removing roughly 7,000 cars off the road, supporting UC ANR's public value of building climate-resilient communities and ecosystems.
The Issue
Increasingly extreme and erratic weather patterns caused by climate change threaten crop yields and farm profits across the state. Growers must continue to adapt to climate stressors, such as increased temperatures and occurrences of drought, and can aid in reducing climate change through their farming practices.
How UC Delivers
A collaborative partnership between the Strategic Growth Council, California Department of Food and Agriculture (CDFA), and University of California Agriculture and Natural Resources (UC ANR) teamed up to support 10 Climate Smart Agriculture Community Education Specialists (CSA CES) throughout the state to provide technical assistance and outreach to promote Climate-Smart Agriculture Incentive Programs. These programs include:
- The Healthy Soils Program, which incentivizes the implementation of climate-smart agriculture practices such as cover cropping, composting, crop rotation, and mulching which reduce erosion and greenhouse gases
- The State Water Efficiency and Enhancement Program (SWEEP), which encourages farmers to install more efficient irrigation systems that decrease water consumption and greenhouse gas (GHG) emissions; and
- The Alternative Manure Management Program (AMMP), which awards funds to livestock producers who decrease their methane emissions by changing the way they manage manure.
Since establishing this partnership in 2019, the UC ANR Climate Smart Agriculture Educator team has provided hands-on assistance to over 200 farmers and ranchers through the complex application process. Collaborating with other CDFA technical providers to host workshops, field days, and events has expanded reach to a greater number of growers, over 120 of whom were able to receive funding after receiving technical assistance. UC CSA CES efforts don't stop at the outreach or application phase; educators work year-round to ensure successful implementation of climate-smart projects.
After the award process, educators assist awardees in completing grant invoicing and contract reporting requirements and connect them with vendors, industry experts, and service providers. UC CSA CES also engage in a variety of additional support activities. For example, to help establish successful cover crop adoption, one educator created a cover crop decision-making tool. A different educator started a small compost spreader rental program to assist small growers in spreading compost. Another facilitates full project management through translation services to a cooperative of Cantonese-speaking awardees.
The Impact
Through assisting awardees in the adoption of practices such as cover cropping, installing solar panels, and installing dairy manure solid separator systems, the 10 UC CSA CES have collectively supported growers in reducing 33,000 MT/CO2 per year, as measured by California Air and Resources Board (CARB) Green House Gas Emission reduction calculator (SWEEP GHG Calculator on CDFA's website), and the HSP Comet planner tool. That's equivalent to removing 7,000 cars from the road per year.
Table A provides an overview of how much GHG has reduced in counties where the UC Climate Smart Agriculture Educator team has helped farmers implement climate-smart practices. Totals for all projects are much higher.
UCCE-County Location |
Total CO2 equivalent in MT/year |
Sonoma, Mendocino, and Lake County |
314.2 |
Merced, Madera, Stanislaus |
5263.31 |
Glenn, Butte, Colusa, Tehama County |
4545.785 |
Yolo, Solano, Sacramento, San Joaquin, El Dorado, Sonoma, Colusa, Sutter |
11716.4 |
Santa Clara County |
58.85 |
Fresno County |
1353.924 |
Kern & Tulare Counties |
7060.283 |
Santa Barbara, Los Angeles, Orange, Ventura County |
630.5 |
San Diego and Riverside Counties |
300.18 |
Imperial County and Riverside County |
3689.1 |
Glenn County grower, Shannon Douglass says, “When producers have the support from the UCCE office that they already know and trust, they are more willing to implement new practices. The application process is intimidating, but with the help from UC, soil healthy practices are becoming much more widely adopted.”
Research shows that Healthy Soils Program practices such as compost application increases the amount of organic matter in soil, amongst numerous other benefits such as increasing the water and nutrient retention capacity of soils, providing a reservoir of nutrients for plants, improving aeration, improving water infiltration, reducing soil erosion, and supporting the abundance and diversity of soil organisms, which can improve plant health. Compost application is just one fundable practice farmers can implement to help reduce greenhouse gases on their operation.
Thanks to this unique partnership with CDFA, UC ANR is able to provide hands-on support to farmers statewide so that they can improve the health of their soils, reduce livestock methane emissions, and improve water use efficiency. In this way, the Climate-Smart Agriculture program contributes to UC ANR's public value of building climate-resilient communities and ecosystems.