Posts Tagged: cover crops
Cover Crops in Rice - Field Demonstration Day
UC Cooperative Extension will host a Healthy Soils Program field demonstration day on...
2024 Rice Cover Crop Field Day Agenda FINAL
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2023 Delta Rice Recap
Rice production in the Sacramento-San Joaquin Delta region has been steadily increasing in recent...
Fire and Dried Cover Crops
Vineyards and orchards have long used winter cover crops to help reduce erosion, improve soil structure and prevent nutrient leaching. Growers are being encouraged to increase their use of cover crops to help capture atmospheric carbon dioxide and fix it as soil organic matter, thus helping mitigate climate change.
However the dry residues resulting from abundant cover crop growth can also serve as a highly flammable fuel if fire occurs at the vineyard or orchard. The risk of fire occurring in any given year is likely small, but many coastal areas of California are rated as having a very high or high fire hazard (see the Fire Hazard Severity Zones Maps).
The picture below offers a clear visual example of just how flammable these dry plant residues can be. This is from an experiment by Livestock and Range Advisor Matthew Shapero and colleagues of how different grazing levels affect fuel quantities and therefore fire behavior. The plots with low fuel levels burn at lower fire temperatures and with lower flame lengths while the higher fuel levels result in much more intense fire behavior.
The California vineyard pictured below in July 2022 is an example of how the management decisions with cover crop residues can result in a very elevated fire risk. This cover crop of oats has full surface coverage and the abundant residues have mostly been left standing. The vines themselves and especially the drip irrigation lines are at very high risk of burning if fire was to ever occur under these conditions. The lack of bare ground under the vine rows will also allow fire to move across the rows and potentially impact the entire vineyard from a single ignition point.
The picture below is from an area in Chile which suffered extensive forest fires in early 2023. In this region, vineyards which had large amounts of dried cover crop residues suffered far more damage than vineyards without such residues. The vineyard on the left had a large amount of dried residues from a lupine cover crop and as a consequence burned very intensely, while the vineyard on the right had very little dried residues and had virtually no direct fire damage to the vines.
Another example from the same region is the effect that the burning of adjacent trees had on a vineyard with little dried residues. In the picture below tall burned pine trees were directly behind the photographer (you can see the shadows of the trunks) but only the near edge of the vineyard was damaged by radiant heat from the burning trees. Undoubtedly many burning embers landed within the vineyard as the trees burned, but the lack of dried residues resulted in no fires within the vineyard.
The take home message from this short article is that dried cover crop residues are highly flammable! With the abundant rainfall in California this past winter we are seeing heavy growth in cover crops this spring which will lead to heavy levels of dried residues this summer. For vineyards and orchards in higher fire risk areas these residues should be managed to help minimize the risk of catastrophic damage if a fire was to occur there.
With all this rain, the trees and the cover crops are thriving, but with an annual cover crop that dries out when the soil moisture dries up, it could be a fire hazard. It should be mowed prior to fire season.
Thanks, Mark Battany, for the reminder - https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=56817
citrus cover crop
Growers invited to see benefits of cover crops in orchards, vineyards
Searchable database of growers experienced in growing cover crops launched
Growers are invited to tour orchards and vineyards and hear from other growers about their experiences with cover crops.
UC Sustainable Agriculture Research and Education Program, UC Cooperative Extension, the Napa Resource Conservation District, and the Community Alliance with Family Farmers have created a searchable database of orchard and vineyard growers experienced in growing cover crops that will help other growers bring the benefits of the practice to their operations.
“The tours are part of a project for which we recently unveiled new tools for orchard and vineyard growers to learn about cover cropping from experienced growers,” said Sonja Brodt, associate director of the UC Sustainable Agriculture Research and Education Program.
The database describes cover cropping strategies, details of field practices, benefits and challenges experienced by cover crop growers in orchards and vineyards in the southern Sacramento Valley (including the Capay Valley) and the North Coast viticulture region. The cover crop grower database is available at https://sarep.ucdavis.edu/covercropsdb.
Feb. 8, 1-5 p.m., Capay Valley tour:
The tour will visit three organic farms in the Capay Valley that are integrating cover crops and grazing in their orchard and vineyard systems. Topics of discussion will include:
- Strategies for integrating cover crops into orchards and vineyards
- Impacts of cover cropping and grazing on soil health
- Funding and information resources for growing cover crops
Speakers will include:
- Rory Crowley, Director of Habitat Programs, Project Apis m.
- Amélie Gaudin, Associate Professor, Department of Plant Sciences, UC Davis, Endowed Chair in Agroecology
- Hope Zabronsky, Climate-Smart Agriculture Program lead, UC Agriculture and Natural Resources
To register for the Feb. 8 tour, visit https://sarep.ucdavis.edu/events/grazing-cover-crops-orchards-and-vineyards-capay-valley-tour.
March 8, 1-4 p.m., Arbuckle area tour:
The tour will visit two conventional farms in the Arbuckle area that are integrating cover crops into their orchard and vineyard systems.
Topics of discussion will include:
- Strategies for integrating cover crops into orchards and vineyards
- Impacts of cover cropping on soil and water balance
- Frost risk protection and prevention
- Funding resources for growing cover crops
Speakers will include:
- Rory Crowley, Director of Habitat Programs, Project Apis m.
- Kosana Suvocarev, UC Cooperative Extension Specialist in Biometeorology, UC Davis Department of Land, Air, and Water Resources
- Hope Zabronsky, Climate-Smart Agriculture Program lead, UC Agriculture and Natural Resources
To register for the March 8 tour, visit https://sarep.ucdavis.edu/events/cover-cropping-conventional-orchards-and-vineyards-arbuckle-area-tour
Cover Crops/Hedgerow Workshop
Hedgerows and Cover Crops and How They Affect IPM
Date: Wednesday; Dec 14, 2022
Time: 9:30AM coffee and tour of cover crop demo, talks will be 10AM - noon
Location: UC Hansen REC, 287 Briggs Rd, Santa Paula, CA 93060
Speakers:
Nic Anne Irvin
- "Nic has been researching biological control of invasive pests in Hoddle Lab at UCR since 2001. She started research on Asian citrus psyllid in 2017, and is currently involved in investigating Integrated Pest Management tools for California citrus growers".
Brent Mossman, RCD
- Brent Mossman is a California native that has a B.S. in Plant Science from Cal Poly Pomona. He is a CA state licensed agricultural Pest Control Adviser, specializing in Integrated Pest Management. Currently working at the Ventura County Resource Conservation District as the Conservation Agriculture Specialist, providing technical assistance to ensure the success of programs such as CDFA's WETA, IIMRLN, and HSP.
Liz Scordato
- Dr. Elizabeth Scordato is an Assistant Professor of biology at Cal Poly Pomona. Her research in Ventura County focuses on using native vegetation restoration to improve ecosystem services in citrus and avocado orchards.
Gordon Frankie
- Dr. Gordon Frankie is a research biologist interested in native bees of California and Costa Rica. One of his prime interests is exploring and implementing ways to extend results of his findings and those of colleagues to a wide variety of audiences. He is currently involved in researching the many insect visitors to avocado flowers. He works closely with UC Coop Extension on this project.
Please reach out to Nicki Anderson with UCCE Ventura for any questions or concerns – nanders@ucanr.edu (805)452-4182
https://surveys.ucanr.edu/survey.cfm?surveynumber=39522It
cover crop workshop dec 2022