- (Public Value) UCANR: Building climate-resilient communities and ecosystems
- Author: Jeffrey P Mitchell
May 17, 2024
Findings from twenty years of soil health research in Five Points, CA have been published in the University of California's California Agriculture peer-reviewed journal's May 1, 2024 issue. https://doi.org/10.3733/001c.94714.
This work has been a large collaborative effort involving twenty-one UC and non-UC coauthors. It began in 1998 initially as an effort to evaluate the potential of reduced disturbance tillage systems to reduce dust emissions from annual cropping systems that are common in California's San Joaquin Valley. It long-term nature however, allowed it to become a unique site for also monitoring changes in soil properties and function under four experimental systems: conventional tillage with no cover crop, conventional tillage with cover crop, no-till with no cover crop, and no-till with cover crop. Crops rotated between tomato and cotton initially, but later during the study, the rotation was diversified to include melons, sorghum, and garbanzo beans.
The work involved the Soil Health Institute's Shannon Cappellazzi, who sampled at the site in 2019. That sampling event led to the site becoming part of a multiple-publication series of articles that reported on soil health impacts in 124 long-term study sites across North America.
https://soilhealthinstitute.org/news-events/a-minimum-suite-of-soil-health-indicators-for-north-american-agriculture/
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- Author: Jeffrey P Mitchell
Robert Willmott not only recently wrapped up his MS thesis research at Fresno State, but he also works full-time as the Farm Manager for his college's student ag farm, is married, and has two small children as well! A full plate, to say the least. In addition to all this, he recently told his story at Fresno State in a 3-minute video that is now posted at You Tube https://www.youtube.com/watch?v=Uo6xZh5sGdA
Working in the Department of Plant Science in the Jordan College of Agricultural Sciences and Technology under his award-winning and Fellow in the American Society of Agronomy major professor, Anil Shrestha, Robert presented his thesis work in an exit seminar on May 14th on campus ahead of being awarded this MS and graduating later this month. His work consisted of a multiple-year study to evaluate the potential of using a roller crimper and strip-tillage for producing silage corn under center pivot irrigation, a new systems approach for San Joaquin Valley dairies that rely on winter and corn silage for animal feed materials. The several years of the study saw quite good success in terminating a variety of winter cover crop mixes using the roller crimper, strong weed suppression during the early corn season, and corn yields comparable to industry standards and the conventional control system that was part of the evaluation.
The work is now being prepared for submission to a scientific journal later this summer. A three-minute You Tube video summarizing Robert's work may be viewed at the link https://www.youtube.com/watch?v=Uo6xZh5sGdA
/span>- Author: Pamela S Kan-Rice
UCCE advisors will present webinars on May 21 and 28
Late spring rains have delayed California's fire season this year, which provides farmers and ranchers an opportunity to improve their wildfire preparedness. Barns, wood fencing, hay and other property commonly found on farms have inherent vulnerabilities to wildfire.
Fortunately, buildings and infrastructure can be hardened and maintained to reduce their vulnerability to fire and fire-related damage to agricultural resources. Having a plan in place to keep livestock safe and healthy is essential to maintaining animal health and resume operations as quickly as possible post-wildfire. Join the UC Agriculture and Natural Resources Fire Network team to learn about wildfire preparedness strategies for farms and ranches.
The two-part webinar series will cover hardening structures and managing livestock during wildfire.
Part 1: Ranch Hardening and Wildfire Preparedness Strategies for Agricultural Structures
- May 21 at 6-7 p.m.
- Join UC Cooperative Extension fire advisor Luca Carmignani and UCCE forest advisor Yana Valachovic to discuss best practices for incorporating principles of structure hardening and defensible space into agricultural structures and operations.
- Register by May 20 at https://bit.ly/3y1MbuP. Link to webinar will be emailed to registrants.
Part 2: The Realities of Managing Livestock Health During Wildfire
- May 28 at 6-7:30 p.m.
- Join UCCE livestock and natural resource advisors and our partners for a set of presentations about managing livestock health during wildfire events and what to do if you find yourself trapped by an approaching wildfire.
- Register by May 20 at https://bit.ly/3y1MbuP. Link to webinar will be emailed to registrants.
- Author: Joanna Solins
Front yard with water-wise landscaping. Photo Credit: Cadenasso Lab, UC Davis
California's urban water agencies have long relied on conservation measures to promote reliability and manage costs. Since landscapes are a large portion of water demand in California cities, many water agencies encourage water conservation by incentivizing the replacement of water-intensive turf lawns with water-efficient or “water-wise” landscaping.
In California's Mediterranean climate, traditional turfgrass lawns require irrigation to maintain their appearance through the hot summer months. Inefficient, poorly managed spray irrigation systems can also result in considerable water loss from runoff and evaporation. Replacing turf and overhead sprinklers with low-water-use plants, alternative ground covers like mulch and kurapia, and more efficient drip irrigation systems can potentially save hundreds of gallons of water per square meter every year.
Although the water savings from turf replacement can be substantial, generating widespread buy-in is a challenge. Landscape renovation can be expensive and intimidating, requiring residents to learn new landscape management practices or pay for professional assistance. In addition, many people appreciate their lawns as spaces for children, pets, or entertainment. Some prefer the look of turfgrass, especially where neighborhood norms promote a unified lawn aesthetic.
To help overcome cost barriers and encourage water-wise landscaping, government agencies and water suppliers commonly offer “cash for grass” programs, in which residents are offered a rebate for landscaping expenses based on the amount of turf they replace. These programs also aim to promote neighborhood adoption of water-wise landscaping by providing attractive examples. Turf replacement incentive programs are likely to expand under proposed new water use efficiency regulations, Making Conservation a California Way of Life (AB1668 - SB606).
While large-scale, regional turf replacement programs in Southern California have been evaluated in peer-reviewed studies, questions remain about the extent and impact of these programs in other parts of the state. How widely are turf replacement programs utilized, and by whom? Are these programs responsible for a substantial amount of water-wise landscaping?
Water-wise landscaping in Sacramento
With these questions in mind, we wanted to understand how both rebate recipients and houses with independently installed water-wise landscaping were distributed across an entire city in inland Northern California. The study was recently published in the Journal of Urban Ecology.
We visually surveyed the front yards of all single-family homes in 100 census tracts across the city of Sacramento—109,062 homes in total—and compared the prevalence of water-wise landscaping with the city's turf replacement rebate data. We especially wanted to understand how this landscape water conservation measure was being adopted by communities of varying socioeconomic and demographic characteristics, and which communities were benefitting from the rebate program.
Front yard with traditional turf. Photo Credit: Cadenasso Lab, UC Davis
In Sacramento, the City's Department of Utilities has offered a rebate of (typically) $1.50 per square foot of turf removed since the summer of 2014. To qualify for the rebate, replacement landscapes must meet several criteria, including efficient irrigation systems and approved plants that cover more than half of the area at maturity. The planting requirement addresses an important concern with turf replacement—the potential for an increase in urban heat. Lawns have a cooling effect through evapotranspiration, and if they are replaced primarily with non-living groundcovers, temperatures could increase. However, such program requirements can make some residents reluctant to participate.
When we conducted our visual survey of front yards in 2018, we found that approximately 10% of Sacramento's single-family-homes had water-wise yards, while 88% had conventional lawns. Only around 3% of water-wise yards were rebate recipients, though, meaning that the vast majority—97%—of water-wise yards were landscaped independently from the city's rebate program. We also found support for neighborhood adoption effects, with clustering of water-wise yards at the city block scale.
The prevalence of independent water-wise yards should be good news for water conservation, since it would not be feasible for the city to fund many thousands of turf replacement projects. However, independent turf replacement projects don't need to comply with the city's requirements for plant coverage or irrigation system efficiency, meaning that they could be contributing to increased urban temperatures or failing to save water.
Our study also showed that water-wise landscaping was more common in census tracts with less diverse, more highly educated, and more affluent populations, as well as fewer households with children. Rebate recipients followed the same trends, suggesting that rebates weren't overcoming barriers to adoption. The uneven distribution of resources necessary for turf replacement—money, time, and information—is likely an important driver of this pattern, along with cultural or functional preferences for lawns. Lawns may play a particularly important role for families as spaces for children to play.
Photo Credit: Cadenasso Lab, UC Davis
A Tool in the Toolbox
Turf replacement is one important tool in the water conservation toolbox, and our research suggests that many residents voluntarily install water-wise landscapes even without a rebate. However, adoption is not equal across communities. The roots of this disparity likely reflect uneven distributions of resources and preferences.
With thoughtful program design and outreach, incentive programs could help overcome some of these barriers, although funding and staffing limitations in water agencies pose a challenge for implementation. For instance, carefully crafted direct installation programs could reach lower-income residents who find it difficult to pay up-front costs associated with rebates. Tailoring efforts to the needs of lower-income and marginalized communities will be important to ensure that they do not end up with unirrigated, high-heat landscapes instead of attractive, water-wise yards.
In the Sacramento region, focus groups conducted for the Regional Water Authority revealed that some residents have a very strong preference for lawns. In these cases, water suppliers may have greater impact by promoting efficient irrigation practices, turfgrass varieties that use less water, and climate-appropriate shade trees. Partial lawn conversions are also a viable water-saving strategy, and one that Sacramento's rebate program supports.
As California's cities grapple with climate change, water reliability, cost effectiveness, and meeting new water use efficiency standards, reducing high-water-use turf lawns will continue to be an important adaptation strategy. Figuring out how to support effective and equitable landscape water conservation programs must be a focus of future research and evaluation studies to promote a California where everyone benefits from climate adaptation measures.
Joanna Solins is an Environmental Horticulture Advisor with UC Cooperative Extension, serving Sacramento, Solano, and Yolo Counties, and is an Affiliate Researcher with the California Institute for Water Resources and the UC Davis Department of Plant Sciences.
Acknowledgments: Many thanks to Erik Porse, Amy Talbot, Jasmin Green, and Mary Cadenasso for their input and assistance with this post.
Additional Reading
Green, J. C., Solins, J. P., Brissette, L. E. G., Benning, T. L., Gould, K., Bell, E. M., & Cadenasso, M. L. (2024). Patterns of water-wise residential landscaping in a drought-prone city. Journal of Urban Ecology, 10(1), juae003. https://doi.org/10.1093/jue/juae003
Alliance for Water Efficiency. (2019). Landscape transformation: Assessment of water utility programs and market readiness evaluation. https://www.allianceforwaterefficiency.org/impact/our-work/landscape-transformation-assessment-water-utility-programs-and-market-readiness
Matlock, M., Whipple, R., & Shaw, R. (2019). Just for the turf of it: Turf replacement as a water conservation tool. Journal of Soil and Water Conservation, 74(5), 449–455. https://doi.org/10.2489/jswc.74.5.449
Pincetl, S., Gillespie, T. W., Pataki, D. E., Porse, E., Jia, S., Kidera, E., Nobles, N., Rodriguez, J., & Choi, D. (2019). Evaluating the effects of turf-replacement programs in Los Angeles. Landscape and Urban Planning, 185, 210–221. https://doi.org/10.1016/j.landurbplan.2019.01.011
Simpson, S.-A., Altschuld, C., Ortiz, A., & Aravena, M. (2023). Green to gold mile: An environmental justice analysis of drought and mitigation policy impacts on home landscapes in Sacramento California. Landscape and Urban Planning, 234, 104729. https://doi.org/10.1016/j.landurbplan.2023.104729
- Author: Pamela S Kan-Rice
A free webinar series titled “Trees to the Rescue: Solutions for Climate Change” will be held on May 14-16, from 4 p.m. to 5:30 p.m. each day. The webinars are sponsored by the University of California Thelma Hansen Fund.
“The webinars aim to increase our understanding of the role of trees in mitigating and adapting to climate change, how to plant the right trees and keep them healthy in urban environments, and the challenges of increasing the number of trees at the local level,” said Annemiek Schilder, director of Hansen Agricultural Research and Extension Center, who is organizing the series. Hansen REC is operated by UC Agriculture and Natural Resources.
Participants will discuss some of the challenges and pitfalls of reforestation, urban greening and tree equity. They will also provide diverse perspectives on tree planting and maintenance efforts and policy at the local level.
“Anyone interested in learning about the importance of trees in urban environments and climate resilience, as well as tree retention in the landscape should join us,” she said.
The agenda for each 90-minute webinar is listed below. To register, visit https://bit.ly/HansenTreesWebinar.
Tuesday, May 14: Trees as a Tool for Climate Change Mitigation and Resilience
4 p.m. Welcome—Annemiek Schilder, Director of Hansen Agricultural Research and Extension Center
4:05 p.m. Opening Remarks—Matt LaVere, Ventura County Supervisor District 1
4:10 p.m. Improving Outcomes of Tree Growing and Forest Restoration Efforts—Karen Holl, Professor of Environmental Studies, UC Santa Cruz
4:50 p.m. Climate Resilience through Urban Greening—Edith de Guzman, UC Cooperative Extension Specialist, Water Equity and Adaptation Policy, UCLA
5:30 p.m. Closing—Annemiek Schilder
Wednesday, May 15: Optimizing Tree Survival in a Changing Climate
4 p.m. Welcome—Emma Volk, Production Horticulture Advisor, UCCE Ventura and Santa Barbara counties
4:05 p.m. Cooling Urban Heat Islands with Climate-Resilient Trees—Janet Hartin, Environmental Horticulture Advisor, UCCE Los Angeles and San Bernardino counties
4:30 p.m. Keeping Trees Healthy from Sapling to Maturity—James Downer, Environmental Horticulture and Plant Pathology Advisor Emeritus, UCCE Ventura County
5:05 p.m. Dealing with the Inevitable Threat of Exotic and Invasive Pests—John Kabashima, Environmental Horticulture Advisor Emeritus, UCCE Orange County
5:30 p.m. Closing—Emma Volk
Thursday, May 16: Tree Advocacy and Planning at the Local Level
4 p.m. Welcome—Julie Clark, Natural Resources Community Education Specialist, UCCE Ventura County
4:05 p.m. Native Tree Restoration with Partners and the Public—Joey Algiers, Restoration Ecologist, Santa Monica Mountains National Recreation Area
4:30 p.m. Panel Discussion (Joey Algiers, moderator):
- Joey Algiers, Santa Monica Mountains National Recreation Area
- Mireille Vargas, County of Ventura Sustainability Division
- Mikaela Randolph, Green Schoolyards America
- Jan Scow, Registered Consulting Arborist, Ojai Valley
- Max Young, Ventura Regional Fire Safe Council
5:30 p.m. Closing—Julie Clark