- Author: Mary Burich, CLEAR Center
Are cattle a secret weapon for taking on California wildfires?
California's cattle ranchers contribute a significant amount to the region's culture, economy and food supply, but do they also inadvertently help to temper the wildfires that have been plaguing the state? And if so, is it a better alternative – environmentally speaking – to letting grasslands burn?
A new study published in the journal Sustainability delves into the topic, weighing the advantages – and disadvantages – grazing cattle bring to the table. Researchers, including scientists from University of California, Davis and UC Agriculture and Natural Resources, set out to calculate the greenhouse gas emissions of cows consuming vegetation that would otherwise burn in wildfires. Then they estimated the GHG emissions that would result should that forage be untouched and therefore, consumed by fire, eventually comparing the two.
Feeling the burn
Given the severity of California's recent wildfires and the belief they will continue and even escalate in the near future, it's a discussion worth having, said Frank Mitloehner, an expert in animal agriculture and air quality from UC Davis, director of the CLEAR Center and one of the researchers who contributed to the peer-reviewed article.
“Each year from 2010 to 2020, California lost on average 89,000 acres of grassland to wildfires,” said Mitloehner, who is also a Cooperative Extension specialist. “In addition to the obvious disruption and devastation they caused, the fires spewed greenhouse gases and harmful particulate matter such as black carbon into the air and into our atmosphere. Those alone threaten climate health and human well-being.”
A fast and furious gas
Cattle are adept at eliminating herbaceous fuel as they graze. However, at the same time, their specialized digestive system produces methane that is expelled most often in the form of enteric emissions … more commonly known as belches. By way of background, methane is a potent greenhouse gas that warms the atmosphere at 25 times the rate of carbon dioxide over 100 years. But it's only in the atmosphere for 10 to 12 years after it's emitted. Following that, it's broken down into carbon dioxide and water vapor.
For that reason, Mitloehner refers to methane as a “fast and furious” gas. Furious because it warms with a vengeance and fast because it does so for only a short time, especially when compared to carbon dioxide. Furthermore, because of the biogenic carbon cycle, whereby plants extract carbon dioxide from the atmosphere for photosynthesis, the warming of methane and its byproducts can end entirely when it's hydrolyzed and used by plants.
How researchers calculated emissions
In order to determine if grazing, methane-emitting cattle are better for the atmosphere than burning grasslands, Mitloehner and the other researchers employed a method known as “Monte Carlo simulation,” a mathematical technique used by scientists to predict outcomes of an uncertain event.
Looking exclusively at methane emissions, they found it's better to have cows eat vegetation than to have wildfires burn it. Granted, it's only marginally better, but when one considers other advantages of animal agriculture and conversely, other disadvantages of widespread, uncontrolled fire, the conversation suddenly shifts.
“Even if cattle provided no other benefit to us, which certainly is not true, we can now make the case that they are helpful to us in yet another way,” Mitloehner said.
Friends or foes?
It goes without saying that one would be hard pressed to find much good to say about wildfires, but that doesn't hold true for animal agriculture. The industry provides jobs and supports the economy in other ways as well. Plus, it is a major source of protein-rich food that is in increasing demand as the world's population continues on a trajectory toward 10 billion people by the year 2050.
Where global warming is concerned, the industry is in the unique position of being able to reach net-zero warming, also known as climate neutrality, if it continues to aggressively chip away at its methane emissions, which Mitloehner asserts is of critical importance to the planet. “Few other sectors can reduce its warming to net zero and still be of service to society, but agriculture can because of the way methane behaves in the atmosphere,” he said.
To be clear, grazing cows are no match for wildfires. Yet, in addition to everything else the sector does for us, slowing the burn and keeping relatively more methane from entering the atmosphere are not nothing.
In addition to Mitloehner, authors of the study are Cooperative Extension advisors Sheila Barry, Devii Rao and Theresa Becchetti; Rowan Peterson, Ermias Kebreab and Minju Jung of UC Davis; and Felix Ratcliff and Kaveh Motamed of LD Ford.
This article was first published on the website of the CLEAR (Clarity and Leadership for Environmental Awareness and Research) Center at UC Davis.
/h3>/h3>/h3>/h3>/h3>- Author: Jeannette E. Warnert
Six UC Cooperative Extension research projects were awarded funding ranging from $100,000 to $250,000 each from the California Department of Food and Agriculture Healthy Soils Program. The grants are designed to fund implementation and demonstration of on-farm soil health practices that reduce greenhouse gas emissions and store carbon.
One of the grant recipients, John Bailey, director of the UC Hopland Research and Extension Center in Mendocino County, will use the $100,000 award to establish a perennial hedgerow at the center. Hedgerows are not traditionally part of standard ranching practices in Mendocino County, where in the past the center's 5,400 acres of rangeland and surrounding areas were grazed by large flocks of sheep.
“At Hopland, we have pivoted our operation to reflect the current state of the sheep industry in California, with reduced overall sheep numbers and decreased individual flock size, so we will use this project to show our smaller-scale sheep owners how they can enhance the ecosystems of their properties,” Bailey said.
Bailey expects the hedgerow to offer many educational, ecological and practical benefits, including enhancing soil health, increasing soil carbon sequestration, and providing habitat and food sources for beneficial organisms, such as pollinators and birds.
There may also be economic benefits to using sustainable practices in raising sheep. The project will explore the financial costs of implementing hedgerows as well as the opportunity for producers to enter a niche fiber market by offering sustainably produced wool to textile companies and consumers willing to pay a premium to support the ecological benefits of Healthy Soil Projects.
“I'm excited about this opportunity to combine the latest knowledge on environmental sustainability practices with the older traditions of livestock grazing in Northern California,” Bailey said. “This is a progressive step that ties in ecological knowledge that can benefit the livestock ranching model by both enhancing their properties and creating new markets for their products.”
The following projects were also funded by CDFA Healthy Soils Program in 2020:
Integrated sustainable nitrogen management in vegetable cropping systems, $250,000
Maria de la Fuente, UCCE county director and advisor, Monterey and Santa Cruz counties
The implementation of climate-smart agricultural practices within intensively managed vegetable cropping systems is extraordinarily challenging. Often conservation practices cannot be effectively implemented due to operational barriers, resulting in very low rates of adoption.
By demonstrating nutrient management strategies in partnership with a large influential vegetable grower in the Salinas Valley, the project aims to encourage broad scale practice adoption.
Recent research has indicated the addition of organic amendments in combination with nitrogen fertilizers potentially reduces nitrogen-derived greenhouse gas emissions and nitrate leaching while increasing soil carbon stocks. These outcomes will generate significant climate benefits in agroecosystems experiencing heavy tillage and fertilizer inputs.
This project has the potential for statewide impact as the researchers are currently working with the developers of COMET-Farm to provide data and coordinate outreach within vegetable cropping systems. Through direct engagement the team will make integrated sustainable nitrogen management more feasible and agronomically favorable for producers.
Using hands-on COMET-Farm-focused field days and a webcasted sustainable nitrogen short course, the project will provide producers with additional tools to make nutrient management planning decisions that have positive climate and soil health outcomes.
Evaluation of compost application to processing tomato fields in the Sacramento Valley, $100,000
Amber Vinchesi-Vahl, UCCE vegetable crops advisor, Colusa, Sutter and Yuba counties
The project will demonstrate compost applications on two farms in two Sacramento Valley counties, Colusa and Sutter. The researchers will work with Westside Spreading LLC and compare two plant-based compost rates to a control (no compost) over three years. Soil health parameters – such as total carbon and nitrogen, pH, EC, organic matter and fertility analyses relevant to tomato crop production – will be measured.
The benefits of compost applications vary depending on how often they are used, how much is applied, crop rotation, and other management decisions, such as whether compost is incorporated or left on the soil surface. Vinchesi-Vahl expects that over time the compost implementation evaluated in this project will result in lower input costs and improved soil function.
Compost application may reduce the need for fertilizer inputs for some of the rotational crops and provide benefits to the microbial community, thereby improving soil structure and reducing heavy conventional tillage needs.
By improving soil health, the research expects plant health will also be improved, leading to better tolerance to pest pressure from diseases and weed competition.
The two demonstration sites will showcase compost applications and their impact on processing tomato production and annual production soil health. These focused demonstrations will be extremely important in showcasing this soil health practice in the local Sacramento Valley region, providing information to growers from the experiences of collaborators at the two sites.
Evaluation of winter cover crop species for their ability to mitigate soil compaction in an annual rotation, $100,000
Sara Light, UCCE agronomy advisor, Sutter, Yuba and Colusa counties
This project has three components:
- Replicated research plots in which three cover crop varieties are evaluated for improvements in soil structure, specifically subsurface soil compaction
- Fieldscale demonstration plots in which varieties thought to reduce soil compaction are planted and visually assessed for performance in the Sacramento Valley
- Small, single-row hand planted plots in the buffer area, in which a wider number of both summer and winter cover crop varieties will be planted for outreach and demonstration purposes
Combined, these components will enable growers to make more informed decisions about cover crop selection and encourage wider adoption of cover cropping. The outreach objective for this project is to reduce barriers to cover crop adaption among regional growers by increasing knowledge and information about varietal selection and field-scale cover crop management, as well as opportunities to improve soil structure using cover crops.
Healthy soils demonstration project with Cardoza Farm, $100,000
Ruth Dahlquist-Willard, UCCE small farms advisor, Fresno and Tulare counties
This project will demonstrate compost application, hedgerow planting, and application of mulch generated from cover crop residue in a vineyard producing organic raisin grapes. Mulch will be applied directly under the vines, providing ground cover that will conserve soil moisture and decrease weed pressure. Generating the mulch on-farm eliminates the need to transport materials from outside sources.
Currently, production of organic raisin grapes involves frequent tillage under the vines. The cover crop between rows and the mulch under the vines will reduce the need for tillage for weed control and increase soil organic matter. These practices will be showcased at field days that will include bilingual training for small-scale, socially disadvantaged farmers in the San Joaquin Valley.
Application of compost to alfalfa to improve soil structure and fertility, $250,000
Kate Scow and Radomir Schmidt, UC Davis Department Land, Air, Water Resources and UCCE advisors Michelle Leinfelder-Miles and Rachael Long
This project will demonstrate compost application to alfalfa for improving soil structure and fertility. Compost is not typically applied to alfalfa; however, manure application to alfalfa is common in the state's dairy regions.
The over half a million acres of alfalfa in California could represent an important repository for compost, for which a large land base of spreading may be needed as municipalities convert organic waste management streams to diversion from landfills.
Alfalfa has the ability to immobilize large amounts of nitrogen and phosphorus, nutrients of concern in the concentration of organic wastes due to their potential to contribute to water pollution. Furthermore, alfalfa growers are interested in the potential of compost to improve soil structure in their alfalfa fields, as many growers report suffering from the large cracks that form in soils during the wet-dry cycles of alfalfa surface irrigation management.
Compost application has been anecdotally reported to alleviate soil cracking in another perennial crop, almond orchards in the Central Valley, but soil structure improvement via management practices like compost application has received little research attention thus far. Westside Spreading LLC is collaborating on this project.
- Author: Chris M Brunner
California leads the nation in agricultural production, producing nearly all the nation's leafy green vegetables, most nut and fruit varieties, and is ranked first in egg and dairy production.
What that means is that California also produces a lot of agricultural waste materials, including lots of manure.
Historically these waste materials have been used as a rich source of compost. However, researchers at UC Cooperative Extension are researching innovative uses for this material.
Dr. Pramod Pandey, a faculty member and Cooperative Extension specialist at the UC Davis School of Veterinary Medicine, focuses on better ways to manage waste material for both large and small farms. Dr. Pandey researches how to convert the organic matter in manure and other waste materials into a renewable energy source that can be used to power our state.
Converting manure to renewable energy
California gets over 27% of its energy from renewable resources like solar wind, and hydroelectric. Our goal is 50% renewable energy by 2030. California is taking steps towards this goal by building a network of dairy digesters which use bacteria to break down dairy manure and convert it into biogas. Clean burning fuels, such as biogas, are a sustainable source for generating energy because when they are burned, harmful by products are not produced.
Big bonus
A bonus is that the solid material left after the digesters have done their job is a fertilizer that can be used to grow the fruits, vegetables and nuts that our state is famous for. This type of fertilizer contains nutrients that are more readily available for plants because the digestion process breaks up organic materials more efficiently than traditional composting. The digestion process also helps reduce the number of harmful bacteria found in manure, making it much safer for use on plants grown for human food.
California leading in discovery and innovation
When we think about where agriculture has been and where it is going, innovation, efficiency and environmental sustainability are hallmarks of our approach in California. People like Dr. Pandey are driving forward research and technology to minimize the impact of agriculture production on the environment. When we think about where agriculture has been and where it is going, innovation, efficiency and environmental sustainability are hallmarks of our approach in California. His multidisciplinary approach to solving this complex problem of agricultural waste materials and water/air quality helps improve the economic wellbeing of farmers, and benefits Californians by providing nutrients for safe, healthy, and nutritious food.
While the importance of California's agriculture might be huge, its footprint on the environment doesn't have to be, and it is researchers like Dr. Pramod Pandey who are ensuring our state leads in discovery and innovation for many harvests to come.
Heather Johnson, Instructional Systems Designer, Gregory Wlasiuk, E-Learning Curriculum Designer, and Dr. Sara Garcia, Project Scientist, with the Western Institute for Food Safety and Security at the University of California, Davis, provided the script for the video which was used in this story. View Heather, Sara and Greg's filming and editing skills in the video below. Greg provides the narration.
/h3>/h3>/h3>- Author: Kat Kerlin
Reposted from UC Davis News
As climate change transforms California's landscape in the years to come, coastal habitats appear to be more resilient than many other places in the state. (Getty Images)
Current levels of greenhouse gas emissions are putting nearly half of California's natural vegetation at risk from climate stress, with transformative implications for the state's landscape and the people and animals that depend on it, according to a study led by the University of California, Davis. However, cutting emissions so that global temperatures increase by no more than 2 degrees Celsius (3.2 degrees Fahrenheit) could reduce those impacts by half, with about a quarter of the state's natural vegetation affected.
The study, published in the journal Ecosphere, asks: What are the implications for the state's vegetation under a business-as-usual emissions strategy, where temperatures increase up to 4.5 degrees Celsius by 2100, compared to meeting targets outlined in the Paris climate agreement that limit warming to 2 degrees Celsius?
“At current rates of emissions, about 45-56 percent of all the natural vegetation in the state is at risk, or from 61,190 to 75,866 square miles,” said lead author James Thorne, a research scientist with the Department of Environmental Science and Policy at UC Davis. “If we reduce the rate to Paris accord targets, those numbers are lowered to between 21 and 28 percent of the lands at climatic risk.”
The report notes that this is a conservative estimate because it only examines direct climate exposure. It does not include increased wildfire or insect attacks on forests, which are also intensifying and likely to increase with further warming. These secondary effects are likely to have large impacts, as well, the authors say. For example, during the recent drought, more than 127 million trees died primarily due to beetle outbreaks, and wildfires have consumed extensive amounts of natural vegetation.
68 percent of LA, San Diego regions impacted
The study features maps of the state and shows the climate risk to 30 different vegetation types under different climate scenarios. It projects that at current rates of greenhouse gas emissions, vegetation in southwestern California, the Central Valley and Sierra Nevada mountains becomes more than 50 percent impacted by 2100, including 68 percent of the lands surrounding Los Angeles and San Diego.
“This is the map of where we live,” Thorne said. “The natural landscapes that make up California provide the water, clean air and other natural benefits for all the people who live here. They provide the sanctuary for California's high biodiversity that is globally ranked. This map portrays the level of climate risk to all of those things. In some cases, the transformation may be quite dramatic and visible, as is the case with wildfire and beetle outbreaks. In other cases, it might not be dramatically visible but will have impacts, nevertheless.”
Resilient areas also identified
The study and its maps are being used by state agencies and land managers to make decisions under changing conditions. Commissioned by the California Department of Fish and Wildlife, the data is helping the agency understand not only which parts of the state are vulnerable to climate change, but also which areas are more resilient, such as some coastal areas and parts of northwestern California, so they can ensure they remain resilient.
“In California, we have good information on the vulnerability of fish and wildlife to climate change,” said Whitney Albright, a project manager with the California Department of Fish and Wildlife. “But we were missing this crucial piece of climate risks to underlying habitat. This study helped fill the information gap. We've already started to use its data in our conservation planning efforts.”
The study also provides a risk assessment for policymakers to consider the benefits to California of reaching Paris climate agreement emission targets that limit global warming to 2 degrees Celsius, and the risks to the state of remaining on the current business-as-usual level of emissions and temperature warming.
Co-authoring institutions included the California Department of Fish and Wildlife, Sequoia and Kings Canyon National Parks, and the U.S. Geological Survey.
The study was funded by the U.S. National Park Service and the California Department of Fish and Wildlife.
/h2>/h2>/figcaption>- Author: Jeannette E. Warnert
A UC Santa Barbara study concluded that planting a home garden can cut carbon emissions to the atmosphere. However, if gardening isn't done right, it could actually contribute to greenhouse gas emissions, reported Nathanael Johnson on Grist.org.
The article looked at five factors that impacted greenhouse gas emissions in home gardens:
- Reduction of lawn area due to replacement by the garden
- Reduction of vegetables purchased from the grocery store
- Reduction in the amount of greywater sent to treatment facilities due to diversion to irrigate the garden
- Reduction in amount of household organic waste exported to treatment facilities due to home composting
- Organic household waste is composted for use in the garden
The abstract of the research article, written by David Cleveland, sustainable food systems professor in the Department of Geography, said:
"We found that (gardens) could reduce emissions by over 2 kg CO2e kg−1 vegetable, but that results were sensitive to the range of values for the key variables of yield and alternative methods for processing household organic waste."
In his Grist story, Johnson provided key points from the research that can help ensure the home garden is climate smart:
- The main reduction from gardening comes from diverting food waste from the landfill, where it rots and emits methane and nitrous oxide. Food waste must be properly composted to prevent the emissions.
- Planting a garden then forgetting about it ends up emitting more greenhouse gases than if you never started.
The article suggests that Californians contact their local UC Master Gardener program for assistance in properly managing a home vegetable garden. Johnson spoke to Kerrie Reid, the UC Cooperative Extension environmental horticulture advisor in San Joaquin County.
"Reid doesn't abandon her plants midway through summer, and she doesn't over-plant and then end up throwing out dozens of thigh-thick zucchinis," Johnson wrote. "Sure, when the cucumbers peak, there are more than she and her husband can eat, she confesses, but they share with their neighbors. The neighbors also come over to harvest herbs from the sidewalk."
The article said readers can find their own version of Reid by looking up a local UC Cooperative Extension Master Gardener program.