Posts Tagged: carbon
Drip irrigation in arid regions can cut greenhouse gas emissions, improve air quality
Study at Desert Research and Extension Center highlights agriculture's sustainability role
Under the blistering sun of Southern California's Imperial Valley, it's not surprising that subsurface drip irrigation is more effective and efficient than furrow (or flood) irrigation, a practice in which up to 50% of water is lost to evaporation.
But a recent study also concludes that drip irrigation can dramatically reduce greenhouse gas emissions from soil – which contribute to climate change and unhealthy air quality in the region – without sacrificing yields of forage crops alfalfa and sudangrass.
“It was really exciting to see,” said lead author Holly Andrews, a National Science Foundation postdoctoral fellow at the University of Arizona. “The crop yield was at least maintained and in some cases increased, but the water use and gaseous emissions were especially decreased under drip irrigation.”
Desert REC crucial to collecting data
Andrews and her colleagues gathered data from field studies at University of California Agriculture and Natural Resources' Desert Research and Extension Center, a crucial hub of desert agriculture research for more than 100 years. Studies in that context are increasingly important, as much of California and the Southwest becomes hotter and drier.
“We already have this history of looking at drip irrigation at this site, so our study was trying to build on that,” said Andrews, who lauded Desert REC's facilities and staff.
In their study published in Agriculture, Ecosystems & Environment, researchers found that – in comparison to furrow irrigation – drip irrigation in alfalfa slashed per-yield soil carbon dioxide emissions by 59%, nitrous oxide by 38% and nitric oxide by 20%.
Nitrous oxide is a greenhouse gas with nearly 300 times more warming potential as carbon dioxide, and nitric oxide is a precursor to ozone and major contributor to air pollution.
While drip irrigation only decreased water demand 1% in alfalfa, the practice led to a substantial 49% decrease in irrigation for sudangrass. For more fertilizer-intensive sudangrass, drip irrigation also reduced soil emissions of nitrous oxide by 59% and nitric oxide by 49% – the result of drip irrigation making those fertilizers more efficient.
Water management can help mitigate climate change
Studying alfalfa and sudangrass – forage crops with very different fertilizer requirements – was a strategic choice by the researchers. They are number one and number three on the list of most widely grown crops by acreage in the Imperial Valley (Bermudagrass, another forage crop, is number two).
With so much land dedicated to producing these crops, the adoption of drip irrigation at scale could deliver significant benefits to residents' health and quality of life.
“The thought that saving water can increase yields while lowering the emission of trace gases that affect regional air quality and Earth's climate is quite encouraging,” said Pete Homyak, an assistant professor of environmental sciences at UC Riverside who contributed to the study. “This is especially true for the Imperial Valley, an arid region where water is a limited resource and where residents are exposed to bad air quality.”
Homyak, who is affiliated with UC ANR through UC Riverside's Agricultural Experiment Station, said that this study illustrates how changes in water management can substantially mitigate agricultural impacts on the environment.
The study findings should encourage growers to replace furrow irrigation systems with drip irrigation infrastructure – especially in combination with financial incentives from the state, such as cap-and-trade and carbon credit programs, that can help defray high installation costs.
“It really is worthwhile if you're thinking sustainability and environmental activism in how agriculture can actually support climate change mitigation,” Andrews explained. “These practices might be a way that we can start to change that picture a little bit – and make agriculture more sustainable by tailoring irrigation management to local climate conditions.”
In addition to Andrews and Homyak, the other study authors are Patty Oikawa, California State University, East Bay; Jun Wang, University of Iowa; and Darrel Jenerette, UC Riverside.
/h3>/h3>/h2>Plant a Tree. Leave a Legacy!
Do you have Spring Fever? If you have adequate space, why not leave a legacy to your children's children by planting a tree? When the right species is planted in the right location with the right care, landscape trees can be enjoyed for 100 years or more. Landscape trees cool urban heat islands, absorb carbon dioxide, filter toxic chemicals from soil preventing them from polluting our waterways, reduce soil and water erosion, reduce internal energy needs and related costs, provide habitat, and beautify neighborhoods.
Spring is a much better times to plant a container landscape tree in California than is summer. Trees incur far less stress if they've been in the ground several weeks rather than having to immediately adapt to high summer temperatures. Cooler weather allows plants to establish roots in their new ‘home' before the harshness of summer sets in. (Deciduous bare-root fruit trees, on the other hand, should be planted during the winter when they are dormant.) Choose recommended species for your climate and micro-climate.
Choose trees based on your Sunset climate zone (more precise than USDA zones for California since they include impacts of high temperatures as well as low temperatures) and your microclimate (shade, soil conditions, space, etc.). Four of my favorite search engines that allow one to search by multiple criteria (size, water needs, flower color, ecosystem functions, pest susceptibility, etc.) are: Inland Valley Garden Planner: https://inlandvalleygardenplanner.org/; Cal Poly, Pomona: https://selectree.calpoly.edu;California Native Plant Society: http://www.cnps.org/cnps/grownative/lists.php; and WUCOLS IV (Water Use Classification of Landscape Species): http://ucanr.edu/sites/WUCOLS
Avoid circled, girdled roots. Remember to inspect the root system of container trees. Avoid purchasing specimens with severely circled and girdled roots. Root pruning will not solve the problem and the resulting tree is much more prone to failure later. This occurs because the upper portion of the tree continues to grow and expand while the root system lacks the breadth and architectural strength to support the tree. Many times a tree will look fine for several years and - seemingly - very suddenly topple in winds that otherwise it could sustain with a more adequate root system. Only when the tree falls does the owner actually notice firsthand that the root system is the same size it was when the tree was planted years before!
Check drainage before you plant. Dig a hole where you are planning on planting the tree, fill it with water, and make sure it completely drains within 24-hours. If it doesn't drain, don't plant a tree there. In some cases, trees are carefully selected based on species and location only to perish ten or more years later due to poor drainage and water-logged soil. Trees often die in these situations due to a lack of aeration setting them up for disease-causing fungal pathogens.
Planting the tree. Dig a hole at least 2-1/2 times the width of the container (in clay or compacted soils make the hole at least 4-5 times wider) up to two inches shallower than the depth of the tree in the container to compensate for settling. Use a shovel or trowel to roughen the soil on the sides of the hole to encourage root growth into the native soil. Remove the tree from the container along with any loose soil that covers the lower part of the trunk. Carefully place the tree in the planting hole, keeping the trunk flare (the area where the trunk widens and connects with the roots) 1-2 inches above the existing grade. Gently fill the hole with the same soil that was removed. Do not add soil amendments or compost, another common cause of circled and kinked roots. Irrigate the tree immediately after planting through the entire root system and slightly deeper. Keep in mind that soils with appreciable clay content absorb water more slowly than sandier soils and need to be watered longer but less often. Water newly planted container trees often through their establishment period, even if they are drought tolerant species. Recently transplanted trees have a small volume of roots that dry out very quickly. Water newly planted trees regularly through the first season. Trees in sandy soils require more frequent watering than do trees in heavier soils. (After trees are fully established, irrigation frequency should be reduced but more water should be added during each irrigation.)
Avoid staking trees unless necessary. Stake trees only if they were staked at the nursery and/or if they are planted in a wind-prone area. Remember to loosen ties on nursery stock before they girdle the trunk. Gently secure any tree requiring staking with two opposing flexible ties on the lower half of the tree, allowing the tree to gently blow in the wind to encourage lower trunk strength. Avoids taking trees tightly, restricting flex. As the tree matures, remember to loosen ties and aim for removing stakes entirely if the tree is self-supporting.
Pruning. Avoid heavy pruning at the time of planting. Remove only broken branches, crossed branches and suckers at the base of the tree.
Fertilizing. Most trees have received adequate nutrition in the nursery and do not need fertilizer at the time of planting.
Mulching. Apply a 2-4 inch layer of mulch three or more inches away from the tree trunk. Organic mulches such as woodchips and compost should be applied and maintained at a depth of 3-4 inches to prevent weed seeds from sprouting. Inorganic mulches (gravel, pebbles, etc.) should be maintained at 2-3 inches. In fire-prone areas, organic mulches near the urban/forest interface should be avoided. Remember to irrigate below the mulch.
For more information on tree planting and care and all other home gardening and landscape topics, contact the UCCE San Bernardino County Master Gardener Helpline at mgsanbern@ucanr.edu
Researchers honored with U.S. Department of Energy Award
On Wednesday, the United States Department of Energy (DOE) granted a Secretary of Energy Achievement Award to a team including two Rausser College researchers, assistant Cooperative Extention specialist Daniel Sanchez and PhD candidate Bodie Cabiyo. The award, with a total of 32 recipients, is one of the highest internal, non-monetary recognitions that DOE employees and contractors can receive.
DOE recognized teams for advancements such as understanding crude oil characteristics, efforts in COVID-19 clinical testing at National Labs, and the development of high-performance computing systems to combat the coronavirus pandemic. Sanchez and Cabiyo's team "Getting to Neutral Carbon Emissions" was selected for their outstanding service and research contributions, both to the agency's mission and the benefit of the nation, in greenhouse gas emissions reduction scholarship.
The team's final report, titled “Getting to Neutral: Options for Negative Carbon Emissions in California,” provides a comprehensive study of technologies that remove carbon dioxide from the atmosphere. It offers frameworks for developing public policy and legislative action based on scientific data, in order to help California achieve carbon neutrality by 2045 or sooner. Sanchez and Cabiyo contributed research to help estimate the amount of forest biomass that can be used in negative emission pathways, as a result of managing one million acres of forest each year. They used economically-driven models to identify the most cost-efficient forest management strategies for the team's Forest Carbon Plan goals.
In the Department of Environmental Science, Policy, and Management, Sanchez studies carbon dioxide removal, bioenergy, and climate policy. With a background in engineering and energy systems, he analyzes the commercialization and deployment of carbon removal technologies. In the Energy and Resources Group, Cabiyo uses interdisciplinary approaches to understand land-based solutions to climate change. Currently, he is studying forest carbon systems and how new technologies impact emissions mitigation.
Learn more about the Getting to Neutral Carbon Emissions Team on the Lawrence Livermore National Laboratory website. Find the full list of Secretary's Honor Award Recipients on the Department of Energy website.
UC Merced becomes the first public research university in the country to achieve carbon neutrality
After a lengthy and rigorous review by independent auditors, UC Merced can proudly announce it is the first public research university in the country to achieve carbon neutrality, two years ahead of its goal.
“UC Merced has been on the cutting edge of sustainability in higher education since its inception. We are proud of our many achievements in reducing our impact on the environment, and this recognition of our carbon neutrality stands among the most meaningful we have yet received,” Chancellor Juan Sánchez Muñoz said.
The campus also made the Green College Honor Roll by The Princeton Review, and ranked No. 5 in the Sierra Club Cool Schools listings.
The campus actually achieved carbon neutrality in 2018, seven years before former UC President Janet Napolitano's initiative goal to have all 10 campuses carbon neutral by 2025. However, the emissions verification and validation take time. UC Merced retained a third-party verifier to review and audit the campus inventories of greenhouse gas emissions specifically from onsite fossil fuel combustion and purchased electricity.
“This was a voluntary step we took, and usually take, to ensure accuracy and transparency,” said Breeana Sylvas, assistant director of the Office of Sustainability. “We wanted to ensure we reflected the full spectrum of our campus emissions profile.”
The inventory results are reported to The Climate Registry (TCR), which conducts its own review. TCR is a nonprofit organization with a mission of empowering its members to reduce their carbon footprints. It does not certify organizations as carbon neutral, but rather works with member organizations to measure, report and verify their carbon footprints.
“I'm very proud that our university has achieved carbon-neutral campus operations and hope we can be an inspiration for others across the state and nation,” said distinguished professor Roger Bales, a member of the UC Global Climate Leadership Council. “The current carbon neutrality announcement is an important milestone in our long journey to create a just, sustainable future.”
Since its founding, UC Merced has set stringent sustainability goals, including zero net greenhouse gas emissions by 2020. The campus is green from the ground up, with every campus building LEED certified by the U.S. Green Building Council.
In addition to the wealth of sustainability and climate-related research projects across all three schools, carbon neutrality has been a campuswide effort, with faculty, staff and students engaged in climate action planning. Contributing programs include faculty integrating sustainable practices in their labs, students analyzing building operations and energy use, and student research on carbon offsets and carbon sequestration. The campus has integrated engagement programs as an opportunity for students to learn about sustainability measures on campus and to carry the culture of sustainability out into the wider world.
“Supporting the campus carbon neutrality goal has been rewarding,” said Carlin Coleman, a graduating senior studying environmental engineering, who works in the Office of Sustainability. “Often, people don't recognize the small measures that can reduce impacts on the environment. It makes me proud to know that my actions are directly affecting our campus goal.”
The entire campus took part in campaigns such as the UC Cool Campus Challenge, and staff members have participated in the Green Offices Program, engaging daily in practices that have helped.
Other efforts include prioritizing student-led programs to reduce greenhouse gas impacts in buildings, developing high-performance buildings, installing renewable energy generation onsite, making clean power purchases and using carbon offsets.
“Our priority is to align operational goals with the mission of the university, student learning and research,” Sylvas said. “This includes reducing energy use, identifying and utilizing clean and renewable sources for onsite combustion, and mitigating remaining emissions generated through gas with offsets.”
Even as the Merced 2020 Project doubled the size of campus and added 13 new buildings over the past three years, UC Merced has been able to keep its energy use-intensity relatively level, she said. While the construction of each building meets high standards, the campus has modeled building efficiency within the state.
“Past revisions of the energy code for the state of California were updated because of advancements made by UC Merced,” Director of Sustainability Mark Maxwell said. “Specifically, lighting control methods designed into buildings, which included multiple controlled lighting systems, occupancy sensors, and lighting control management systems.” The campus is looking to eliminate fossil fuel combustion in future capital developments, he said.
Besides its own goals and the UC-wide carbon neutrality initiative, UC Merced is also a signatory of the Second Nature Carbon Commitment, an extension of the Presidents' Climate Leadership Commitments. Second Nature is a non-governmental organization committed to accelerating climate action in, and through, higher education, and recognizes schools that have achieved carbon neutrality.
“Congratulations to UC Merced on this major accomplishment,” Second Nature President Tim Carter said. “Achieving carbon neutrality for higher education institutions is not an easy undertaking. It requires tremendous commitment and continuous work on the campus and within their community to do so. To do so earlier than their goal neutrality date illustrates just how committed UC Merced is.”
Taken all together, UC Merced's commitment to sustainability has had a positive effect on the campus community and the region, as well. You can learn more about the campus's carbon neutrality efforts and successes online.
“We have a dynamic, robust program that is engaging and utilizing multiple avenues that have achieved and are maintaining our goal, and we thank our incredible campus community members, all of whom are making a difference. We are just getting started,” Sylvas said. “This is just the beginning.”
Composting Basics
If you've ever felt confused by the process of composting, you are not alone! Most gardeners...