Posts Tagged: conservation
CASI’s Mitchell announces long-term NRI Project publication in Cal Ag on Don York’s KMJ580 AM morning “Ag Report” radio program, May 23, June 4, and June 6, 2024
In an effort to extend information on CASI's twenty-year conservation agriculture study that has been conducted at the University field station in Five Points, CA and that has been recently published in the journal, California Agriculture, Jeff Mitchell provided three radio interviews on the morning Ag Report that Don York produces for KMJ580 AM each morning out of Fresno. The segments aired on May 23rd and on June 4th and 6th, 2024 and are available below. Mitchell shared findings of the long-term “NRI Project” that since 1998 has examined four production systems – standard tillage without cover crop, standard tillage with cover crop, no-till without cover crop, and no-till with cover crop.
The NRI Project started as an effort to determine the potential of reduced disturbance tillage in terms of generating or producing less dust and in the early 2000s found that dust can be significantly reduced by as much as 80% with a variety of reduced tillage practices relative to standard tillage techniques that have been widely used in annual crop fields throughout the San Joaquin Valley since the early 1930s. The recent findings from the unique long-term study have shown that several soil health indicators including aggregation, water infiltration, biodiversity, and surface carbon were improved through the long-term use of cover crops with reduced disturbance tillage.
In the interviews, Mitchell points out that the systems that were evaluated and developed in the NRI Project were not at all easy to implement and required considerable trial-and-error effort to achieve. Yields, for instance, of cotton in the early years under the high residue, no-till cover crop system lagged behind the standard tillage, however once effective planting techniques were learned to establish the cotton crop. There were no yield differences between the two tillage systems for the next several years.
The results of this study that included 18 coauthors can be seen at https://doi.org/10.3733/001c.94714
Jeff Mitchell on KMJ Ag Report 5-23-24
Jeff Mitchell on KMJ Ag Report 6-4-24
Jeff Mitchell on KMJ Ag Report 6-6-24
Screenshot 2024-06-07 090600 Cal Ag Screenshot Cal Ag
20-year summary of soil health research in Five Points, CA published in California Agriculture!
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/
/span>
Screenshot 2024-05-17 080919 Cal Ag
Fresno State MS student shares his research work on strip-tillage!
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>
Screenshot 2024-05-17 074737 Fresno State
Patterns and drivers of water-wise landscaping for urban water conservation
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
CASI hosts the Soil Health Institute's US Regenerative Ag Cotton Program leaders - April 11 and 12, 2024
April 12, 2024
The UC ANR CASI Center hosted five members of the Soil Health Institute's US Regenerative Ag Cotton Program in the San Joaquin Valley on April 11th and 12th, 2024. The Soil Health Institute (SHI) is a non-profit organization based in Morrisville, NC that conducts research and extension education related to soil health management. Five SHI members, Diana Bagnall, David Lamm, Jessica Kelton, Emily Ball, and Nate Looker, took part in the two-day tour of six San Joaquin Valley farms and the California Cotton Ginners and Growers Associations. San Joaquin Valley farmers who hosted the SHI members included Mark Borba of Borba Farms in Riverdale, CA, Mark McKean of McKean Farms also in Riverdale, Tony Azevedo of Stone Land Company in Stratford, CA, Cannon Michael and Derek Azevedo of Bowles Farming in Los Banos, Gary and Mari Martin of Pikalok Farms in Mendota, and Gary Smith of Ingleby Farms in Burrel. Roger Isom, President of the CCGGA in Fresno, also hosted the SHI guests.
SHI requested help from CASI with the cotton tour and discussions that took place as an effort to expand their national Regenerative Ag Cotton Program to California in 2024. The tour provided excellent opportunities for SHI to learn about California cotton and to make connections with leading cotton farmers in the San Joaquin Valley who may become part of the baseline soil sampling project that SHI is looking to conduct with cotton producers this year.
In addition to the farmers who generously hosted the SHI guests, several other local California folks including Cary Crum, Kimber Moreland, Rob Roy, Jacob Wright, and Olivia Peters helped CASI's Jeff Mitchell in sharing information about California cotton systems.
DSC0148-1 FINAL
DSC0172-1 FINAL