Posts Tagged: cover
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
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
Sheep Grazing in Vineyards and Fields
Vineyard grazing flyer (002)
Cowpeas Can Make Money in Spanish Mandarins
If you can sell your cowpeas, fava beans and barley, you can make money in Spain and apparently not use any more water than if just growing the mandarins. And coastal growers should look at the fresh market. Have you ever tasted a fresh green cowpea or fava bean? Pretty darn good and consumers think so, as well.
A Diverfarming project study compares the environmental footprint and the economic performance of traditional mandarin monocropping as opposed to growing mandarin intercropped with herbaceous crops and the use of deficit irrigation
The transformation towards intensive agriculture has led to agricultural practices in Europe that have centred on increasing the yield and reducing costs in recent decades, and which involve a major dependence on external sources of agrochemicals and energy. These intensive monocropping systems have generated biodiversity losses, water contamination, and high rates of greenhouse gas emissions, as well as degrading the soil and reducing the ecosystem services.
Faced with this situation, the European Diverfarming project has trialled the diversification of crops throughout the European Union, seeking the best practices to combine crops and focusing on reducing inputs to find the best options to preserve the sustainability of the systems and increase the resilience of the European agricultural sector. To do so, it is also necessary to know the impacts of these practices both at environmental as well as economic level.
With the aim of knowing the environmental footprint and the economic performance of the introduction of herbaceous crops among the alleys of the mandarin trees using controlled deficit irrigation in a mandarin grove located in the Region of Murcia, a team of researchers from the Universidad Politécnica de Cartagena have carried out a life-cycle assessment of the crop and an evaluation of the costs and income of the farm for the three years that the experiment in this case study was carried out.
Although the growing area increased with the introduction of the herbaceous crops (in this case purslane, cowpea, broad beans, and a barley-vetch mix), no detrimental effects occurred in terms of exhausting resources, acidification, or global warming. Therefore, the practice of intercropping did not cause additional contamination or other environmental impacts. This, in addition to the results of the increase in nitrogen and organic carbon content and in the soil and the reduction in erosion and run-off makes the introduction of herbaceous crops in the alleys of the mandarin trees a good sustainable environmental option to cope with the current challenges of the sector.
In economic terms, the financial security of the agricultural community also becomes a key element for successfully adopting diversified systems. This study highlights, through the economic assessment, that intercropping can lead to an increase in production costs, mostly related with a greater demand for labour in comparison with monocropping. However, the study also concludes that “the correct choice of intercropping practices can bring economic advantages”. The results showed that the mandarin crop with purslane and broad beans as intercrops could be profitable and reduce the risk for the grower against volatile prices in the main crop.
In this way, considering all the potential environmental and economic benefits of intercropping practices, these systems arise as a tool to move towards more sustainable and profitable agricultural systems. The valorisation of agricultural products that are more respectful to the environment on the part of consumers and the backing of public funding (e.g., direct help to growers who introduce intercropping) are key aspects to drive the adoption of these practices.
pixie harvest 2
Cover Crops and Healthy Soils
Lockeford Plant Materials Center
Cover Crop and Soil Health Field Day
April 6, 2022 - 10 -12pm
Agenda
Fava Bean Advantages in Cover Crop Mixes – Hossein Zackeri, Chico State
Cover Crop performance for the Central Valley - Tom Johnson, Kamprath Seed
Conservation Cover Study – Perennial planting for orchards and vineyards – Margaret Smither-Kopperl, NRCS
Field Border Study in the Healthy Soils Program – Anthony Fulford, UCANR
Changes to Soil Health at the PMC - Demonstration - Z. Kabir, NRCS
Location: Lockeford PMC, 21001 N. Elliott Rd., Lockeford, CA 95237
Please Register for the event here: https://surveys.ucanr.edu/survey.cfm?surveynumber=36926
cover croppwed citrus