Posts Tagged: greenhouse gas

UC Cooperative Extension to investigate healthy soil practices with CDFA grants

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.

A home garden can help reduce greenhouse gas emissions

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:

1. Reduction of lawn area due to replacement by the garden
2. Reduction of vegetables purchased from the grocery store
3. Reduction in the amount of greywater sent to treatment facilities due to diversion to irrigate the garden
4. Reduction in amount of household organic waste exported to treatment facilities due to home composting
5. 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.

San Joaquin Valley row crop growers help control greenhouse gases

Reporter Dennis Taylor of the Visalia Times-Delta wrote about research results recently published by UC Agriculture and Natural Resources scientists that may allow farmers to be part of carbon cap-and-trade agreements.

Taylor interviewed lead researcher Jeff Mitchell, UC ANR Cooperative Extension specialist and chair of the UC ANR Conservation Agriculture Systems Innovation Center.

Long-term research by UC ANR has documented the capacity for farmland in the San Joaquin Valley managed with certain conservation practices to sequester carbon, results that could give farmers a seat at the carbon trading table, the article said. The study was published this month in the Agronomy Journal.

"We're reducing the atmospheric load of carbon dioxide, a greenhouse gas that plays an important role in global warming," Mitchell said. "Proving a stable storage location for carbon could allow agriculture to be part of future cap-and-trade programs."

The ANR news release on the research was also picked up by the Central Valley Business Times, California Political Review and the Red Bluff Daily News.

 

Biodigester turns campus waste into campus energy

More than a decade ago, Ruihong Zhang, a professor of biological and agricultural engineering at the University of California, Davis, started working on a problem: How to turn as much organic waste as possible into as much renewable energy as possible.

Last week, on Earth Day, the university and Sacramento-based technology partner CleanWorld unveiled the UC Davis Renewable Energy Anaerobic Digester (READ) at the campus' former landfill. Here, the anaerobic digestion technology Zhang invented is being used inside large, white, oxygen-deprived tanks. Bacterial microbes in the tanks feast on campus and community food and yard waste, converting it into clean energy that feeds the campus electrical grid.

“This technology can change the way we manage our solid waste,” Zhang said. “It will allow us to be more economically and environmentally sustainable."

It is the third commercial biodigester CleanWorld has opened using Zhang's technology within the past two years and is the nation's largest anaerobic biodigester on a college campus.

The system is designed to convert 50 tons of organic waste to 12,000 kWh of renewable electricity each day using state-of-the-art generators, diverting 20,000 tons of waste from local landfills each year. It is expected to reduce greenhouse gas emissions by 13,500 tons per year.

The READ BioDigester encompasses several of the university's goals: reducing campus waste in a way that makes both economic and environmental sense, generating renewable energy, and transferring technology developed at UC Davis to the commercial marketplace.

The biodigester will enable the more than 100 million tons of organic waste each year that is currently being landfilled in the U.S. to be converted to clean energy and soil products. The READ BioDigester is a closed loop system, moving from farm to fork to fuel and back to farm. Whatever is not turned into biogas to generate renewable electricity can be used as fertilizer and soil amendments — 4 million gallons of it per year, which could provide natural fertilizers for an estimated 145 acres of farmlands each day.

Nearly half of the organic waste, or feedstock, needed to operate the biodigester to full benefit will come from UC Davis dining halls, animal facilities and grounds. CleanWorld is working with area food processing and distribution centers to supply the remaining amount. Meanwhile, UC Davis will earn 100 percent of the project's green energy and carbon credits and receive all of the electricity generated.

Anaerobic digestion is an age-old process. However, Zhang's patented technology made it more efficient — capable of eating a broader variety and bigger quantity of waste, turning it into clean energy faster and more consistently than other commercial anaerobic biodigesters.

View a video about the UC David biodigester here:

(This blog post is condensed from a UC Davis news release about the biodigester.)

Additional information:

• Read the full press release
• Download biodigester photos
• Vine video: From lunch to lights
• Visit http://www.cleanworld.com/

UC to measure energy and greenhouse gas footprints of orchard crops

What if the trees in an orchard could be considered a savings account for energy and carbon? When determining the value of an orchard, we may account for the fruits it bears, the air it cleans, and the labor it employs. But with California climate policies in place and carbon becoming a tradable commodity, we may also be able to calculate and account for the long-term value of a tree itself.

A new study underway at the UC Sustainable Agriculture and Research and Education Program (SAREP) aims to help growers and policymakers better understand the energy use, greenhouse gas emissions, and carbon sequestration potential of orchard systems throughout California.

As trees grow, they draw carbon dioxide from the air to create sugar and cellulose for food and growth, locking some of that carbon into their wood as the trees age — in some trees for 25 years, in others like walnuts, for upwards of 150 years. Proper use of that carbon at the end of an orchard's life can have major implications for the overall greenhouse gas footprint of an orchard operation. Trees used for power generation after orchard removal have the potential to offset fossil-fuel related emissions created throughout the orchard's life.

"Our preliminary study in almonds shows that the amount of fossil fuel emissions saved in this way is equal to almost three-quarters of the greenhouse gas emissions generated during the whole 25-year lifespan of the orchard, using current practices," says the project's director, Sonja Brodt, SAREP academic coordinator. "We think that this information could help to position orchard crops favorably for a consumer base that is increasingly climate-smart."

This study, funded by the California Department of Food and Agriculture's Specialty Crops Block Grant Program, will focus on prunes, peaches, walnuts and almonds in all of the primary production regions of the state.

Many farm management practices have an energy use component that the project will consider including water and fertilizer use, tractor use and post-harvest transportation. By understanding which parts of orchard operations use the most energy as well as how much energy is required to manufacture and distribute inputs before they even arrive at the farm, growers can increase the efficiency of their practices. Industry groups can also develop more scientifically-sound grower sustainability programs to improve energy efficiency more broadly for the state's many tree crop growers.

"Energy is one input into agriculture that we have not thought about much from a whole supply chain point of view," says Gabriele Ludwig of the Almond Board of California, which funded a preliminary study on energy use and emissions in almond production and handling. "Yet the costs of energy, especially from fossil fuel sources, keep going up. The life cycle assessment approach used in this project can provide an analysis of where increased efficiencies may be possible."

The project's collaborators include the UC Cooperative Extension's Sutter-Yuba office, the UC Davis Department of Civil and Environmental Engineering, Department of Land, Air, and Water Resources, the Department of Plant Sciences, and graduate students in Horticulture and Agronomy and International Agricultural Development.

By working with growers throughout the state, project staff will be able to ensure that orchard management practices included in the project's models are representative of current practices. Growers interested in providing confidential input about their orchard practices are invited to contact Brodt at sbbrodt@ucdavis.edu or (530) 754-8547.

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