- Author: Ali Montazar
UC ANR research helps Southern California farmers conserve water by an average of 15% and encourages others to make region-specific crop management and irrigation decisions, contributing to UC ANR's public value of protecting California's natural resources.
The Issue
Water scarcity will become a more significant concern in the Colorado River Basin due to altered weather patterns and multi-year droughts. Knowledge of the evapotranspiration (ET) of crops produced in Southern California will be critical to better managing limited water resources. Accurate information on crop water use and crop coefficient (Kc) is an immediate need for on-farm water conservation programs in the low desert region. Growers, irrigation and water districts, and researchers typically use crop coefficients developed in the Central Valley or other areas. Formulating this irrigation information for the Southern California region is crucial since the region has differences in climate, soil types and conditions, cropping systems, and irrigation and farming practices.
How UC Delivers
Extensive field measurements were conducted in 53 commercial fields over the last three-year for 11 agricultural commodities, including alfalfa, carrots, onions, Klein grass, date palm, lemons, olives, sugar beets, spinach, sunflowers, and wheat. The residual of energy balance method, which used a combination of surface renewal (SR) and eddy covariance (EC) techniques, was used to determine the actual ET and crop coefficients in each site. In addition, Tule technology, an affordable crop water use measurement sensor, was set up at the experimental sites for extension purposes. Twenty fully automated SR-EC ET towers, 60 Tule technology sensors, and more than 700 other various soil moisture sensors were set up in the Imperial, Coachella, and Palo Verde valleys. The study's crop coefficients and irrigation management best practices were periodically shared with cooperative growers to evaluate their practices, learn about the advantages of sensor-based irrigation management, and encourage utilizing the tools and information to improve irrigation management and yield production. Additionally, the information was discussed with local irrigation and water districts in different events and meetings, and study findings were published in several extension articles and peer-reviewed journals.
The Impact
As a result of collaborating in this study, a cooperative date grower found that water use efficiency improved by 18%, puffy skin diseases of date fruits reduced, and fruit quality improved overall. The study, which includes nearly 50% of crops grown in the region, helped participating growers conserve water by 15% on average across various agricultural commodities. Furthermore, these findings provide evidence about the benefits of the residual of energy balance method, water use sensors, and soil moisture sensors specifically in southern California. The most accurate crop coefficients for the cropping systems and the best factual guidance available provide significant benefits to the region by supporting enhanced water and nutrient use efficiency and drought resilience information for profitable and sustainable crop production. The tools developed by this program have the potential to yield large dividends through not only improved resource use efficiency but also best management practices and crop quality. Local irrigation and water districts may utilize the information in their on-farm efficiency conservation and water delivery programs. Additionally, adopting these knowledge-based information and tools in combination with CIMIS (California Irrigation Management Information System) or Spatial CIMIS data may benefit the region more than $7.5 million in water and energy savings.
These outcomes demonstrate UC ANR's public value of protecting California's natural resources. The following links are publications associated with this study that have been shared in agricultural journal and research settings:
UC ANR Agricultural Brief: May 2021
Vegetables West July/August 2020 Issue
UC ANR Agricultural Brief: December 2019
UC ANR Agricultural Brief: July 2019
UC ANR Agricultural Brief: October 2018
UC ANR Agricultural Brief: July 2018
UC ANR Agricultural Brief: March 2018
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- Author: Ali Montazar
UC ANR research on drip irrigation shows potential to reduce downy mildew incidence while improving water quality and resource-use efficiency, contributing to increased water-use efficiency and improved food safety.
The Issue
Spinach is a leafy green quick-maturing, cool-season vegetable crop. Downy mildew on spinach is a widespread and very destructive disease in California. It is the most significant disease in spinach production, causing crop losses in all areas where spinach is produced. Most conventional and organic spinach fields are irrigated by solid-set or hand-move sprinklers. However, overhead irrigation may contribute to the speed and severity of downy mildew epidemics within a field when other conditions such as temperature are favorable. It is postulated that new irrigation management techniques and practices in spinach production may have a significant economic impact to the leafy greens industry through the control of downy mildew.
How UC Delivers
The main objective of this study was to explore the viability of adopting drip irrigation for organic and conventional spinach production. Field experiments were conducted at the UC Desert Research and Extension Center and three commercial fields in the low desert of California over four crop seasons (2018-2021). Several treatments and comprehensive data collection were carried out to optimize drip system design, irrigation and nitrogen management strategies, planting method, and evaluating the effects of drip on plant growth and downy mildew incidence, and seed germination by drip irrigation.
The results of this multi-year study demonstrated that drip irrigation has the potential for producing profitable spinach in the California crop production system. No significant yield difference was observed among sprinkler treatments and most drip treatments in the 2021 trial. An overall effect of the irrigation system on downy mildew was observed, in which downy mildew incidence was two-to-five times lower in plots irrigated by drip when compared to sprinklers. The likely mechanism for reducing downy mildew incidence is the reduction in leaf wetness resulting from drip irrigation. Leaf wetness is a critical factor for infection and sporulation by the downy mildew pathogen.
The Impact
The findings of the aforementioned study show that adopting drip irrigation for high-density spinach plantings can reduce incidence of downy mildew and related food safety risks and crop loss. As a result of participating in research trials, a cooperative grower reported a considerable cost reduction of $300 per acre due to less/no water treatment applications for downy mildew control and food safety issues in conventional spinach under drip irrigation. The findings of this study show that adopting drip irrigation for high-density spinach plantings can be a solution to reduce food safety risks and losses from downy mildew, conserve water and fertilizer, and reduce greenhouse gas emissions. A lower energy cost of $200 per acre is estimated for spinach producing under drip irrigation.
Several factors influence appropriate drip irrigation management in spinach including system design, soil characteristics, and environmental conditions. Drip irrigation offers the potential for precise water management, as well as the ideal vehicle to deliver nutrients in a timely and efficient manner. However, achieving high water- and nutrient-use efficiency, while maximizing crop productivity requires intensive and proper management, particularly in organic baby spinach. The knowledge-based information and findings of this study have been shared with growers and stakeholders through several media interviews, presentations in workshops/webinars, and extension and peer-review publications, contributing to UC ANR's public values of resource conservation and safe, sufficient food for all. The following links are some of the publications associated with this study in Western Farm Press, the Desert of Review, the Holtville Tribune, California Ag Today Radio, Vegetables West, California Organic Farmer, Journal of Agriculture, Agricultural Briefs, and UC ANR Knowledge Stream:
The Holtville Tribune - May 2021
California Ag Today Radio - March 2021
Western Farm Press - February 2021
Journal of Agriculture - August 2019
California Organic Farmer - August 2019
UC ANR Knowledge Stream - August 2019
UC ANR Agricultural Briefs - June 2019
UC ANR Agricultural Briefs - February 2019
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- Author: Steven M. Worker
- Author: Lupita Fabregas User
- Author: Claudia P. Diaz Carrasco
- Author: Lynn Schmitt-McQuitty
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The 4-H Latino Initiative achieves positive youth outcomes and advances practices on culturally relevant programming, contributing to UC ANR's public value of developing an inclusive and equitable society.
The Issue
Over 39% of Californians identify as Hispanic or Latino. Growth estimates project that Latinos will make up half of all Californians by 2060. In the K-12 public school system, more than 54% of students identify as Latino or Hispanic. Yet, until recently, the youth membership of UC Agriculture and Natural Resources (ANR) 4-H programs did not represent the state's Latino population.
How UC Delivers
In 2015, UC ANR provided $2 million to fund the UC 4-H Latino Initiative, a three-year effort from 2016 to 2019 to develop, adapt, implement, and evaluate culturally relevant and responsive 4-H youth development programs. Seven counties — Kern, Merced, Monterey, Orange, Riverside, Santa Barbara, and Sonoma — were selected, representing rural, suburban, and urban communities. Each county received funding to hire a bilingual and bicultural 4-H program staff. Additionally, UC ANR hired an assistant state director for diversity and expansion. The goal was to develop, deliver, and assess culturally responsive program models to recruit and retain Latino youth, families and volunteers into 4-H.
Over three years, each county made progress increasing its reach with youth using a combination of program models and delivery modes. Statewide, youth enrollment grew from serving 1.1% of the school-aged population in 2016 to 1.9% at the end of year three (2019). The number of Latino youth enrolled in 4-H grew 104% from the year before the initiative to year three. Specifically, the 2016 program year had 34,040 Latino youth members, which was 40% of total 4-H membership, and the 2019 program year had 69,383 Latino youth members, making up 47% of total 4-H membership.
We generated new knowledge to advance the field of culturally responsive youth development programming. For example, in a study of bicultural program staff, published in the Journal of Youth Development, we reported on the competing demands to build relationships, engage youth, and show results, with lessons to help shape future efforts (Worker et al., 2019)
The Impact
Newly recruited Latino young people experienced positive outcomes from participating in 4-H programs such as improvements in mindset and social skills. Additionally, we found that the program experience including relationship building and youth engagement, were similar across community clubs and 4-H Latino Initiative programs (Worker, Fábregas Janeiro, & Lewis, 2019). As a result, the 4-H organizational culture shifted to become more accepting and welcoming, particularly with implementing new, culturally responsive programming. Adopted strategies include incorporating positive development of ethnic identity, tailoring to the needs and interests of local and regional Latino youth and families, removing barriers to participation, and increasing cultural competencies among 4-H volunteers. Resources developed by the Latino Initiative are now located on a web page and continue to be accessed by 4-H academics, staff, volunteers, and 4-H professionals across the nation. They include resources for assessing, implementing, and evaluating culturally responsive programs, as well as marketing and communicating about efforts to engage Latino youth.
“I love having 4-H in my school. I decided to help coach a team, even if I don't know much about soccer. It has been so much fun to learn with the kids and play soccer with them." – Elizabeth, 4-H volunteer soccer coach
/h3>/h3>/h3>/h3>Final Report 2018-2019 - UC ANR 4-H Latino Initiative
- Author: Andra Nicoli
- Author: Pam Kan-Rice
- Author: Mary Vollinger
- Author: Laura Vollmer
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CFHL, UCCE San Mateo partnership with JobTrain results in 128 adult students increasing food resource management life skills, contributing to UC ANR's public value of safeguarding abundant, healthy food for all California.
The Issue
Research indicates that approximately 134,443 people in San Mateo County live at or below 185% of the poverty level and 18% are SNAP-Ed eligible. Given the pandemic and ongoing economic crisis, this number is expected to grow next year. Of the SNAP-Ed eligible population, 66% of adults are overweight/obese.
How UC Delivers
To address these health concerns, CalFresh Healthy Living, UCCE San Mateo County (CFHL, UCCE) has partnered with JobTrain, a non-profit education and training institution delivering the food resource management curriculum “Plan, Shop, Save and Cook” to adult participants for the past eight years. JobTrain provides career training in fields such as culinary arts, certified nursing assistant (CNA), medical assistance, carpentry, building maintenance, and IT support and services. While this training enables students to move from unemployment into careers offering self-sufficiency, the nutrition and food resource management classes offered through partnership with CFHL, UCCE offer important life skills in consumer decision making, dietary health and wellness.
“These valuable life skills complement the vocational training they receive at JobTrain,” said Elaine Silver, Nutrition Educator for CFHL, UCCE in San Mateo and San Francisco counties. During lessons, JobTrain students learn about MyPlate, shopping on a budget, preparing healthy meals and snacks for families, reading food labels, and the importance of physical activity.
Since October 2020, 128 JobTrain students have taken Silver's virtual Plan, Shop, Save and Cook lessons. In past years, these lessons were delivered in person, but switched to Zoom during COVID-19 stay-at-home orders to allow JobTrain students to continue building these important life skills.
The Impact
Overall, 88% of the students reported improvements ranging from 43% comparing unit prices more often to 60% reading/using nutrition facts labels more often. In addition, 28% of participants reported running out of food less often before the end of the month – suggesting they were more food secure after taking the course.
“I started cooking healthier meals for my family, including veggies,” wrote one survey respondent. “Some of the changes I've made is that I now look at the unit price, just to make sure I am getting my money's worth,” wrote another student. “Also, I have started taking a grocery list with me so that I can make sure I can stay on budget and not buy things that I do not need.”
These outcomes demonstrate how CFHL, UCCE San Mateo County is contributing to UC ANR's public value of safeguarding abundant and healthy food for all Californians. When asked about the impact these virtual classes have had on students' lives, the feedback from JobTrain's instructors has been overwhelmingly positive. In addition to increasing food resource management, instructors noted how much students look forward to classes, how they benefit from incorporating new healthy practices, and that learning more about healthy living helps bolster education for students entering the healthcare field.
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- Author: Katherine Jarvis-Shean
- Author: Allan Fulton
Agricultural clientele utilize Extension information to inform irrigation management decisions, potentially improving water use efficiency and protecting California's water resources.
The Issue
For farmers to grow high-yielding and good quality crops and be good stewards of our finite water resources, they need to know how much water is used by their crop and how much to refill the soil with irrigation. Weather conditions and the crop's life stage determine the water use, also known as crop evapotranspiration (ET). When farmers have accurate crop ET information available, they can more closely apply the appropriate amount of water at the right time and grow more and better quality food and fiber with each unit of water.
How UC Delivers
Since 1995, UC ANR has collaborated with the Department of Water Resources (DWR) to deliver weekly crop ET estimates to growers for the major crops grown in California. These ET estimates integrate real-time, on-the-ground weather measurements taken by DWR and decades of research by UC ANR on crop water use. These reports provide growers with representative estimates of crop ET each week and a running total of crop water use as each crop develops. The weekly rates of ET can be related to the water application rate of an irrigation system to help determine how frequently to irrigate and how long to run a system. Comparing cumulative ET early in the season to the available soil moisture can help decide when to apply the first irrigation of the season. At the end of the season, a comparison of the seasonal ET to total applied irrigation water provides a yardstick to assess irrigation efficiency. Beginning in 2000, methods of delivering these weekly reports expanded to include email and blogs. In 2015, these reports expanded to UC ANR offices throughout the Central Valley to serve more than 1,200 clientele throughout California.
The Impact
In 2019, a one-time survey was sent to about 1,200 clientele throughout California, including growers, agricultural land managers, and crop advisors to understand how the weekly ET reports were being used, quantify the impact of use of the emails, and assess the needs of irrigation education. The survey findings indicated that 70% of clientele use these weekly ET reports in irrigation management decisions. Of that 70%, 75% use the information to inform how long to irrigate, 73% how frequently to irrigate, 53% when to begin the irrigation season, and 39% when to end the irrigation season.
Research has shown that scheduling irrigation based on ET can improve plant health and yields, translating to more crop per drop. Previous UC ANR research has demonstrated that California growers save approximately $64.7 million per year by using CIMIS weather station data. In this way, UC ANR contributes to improved water use efficiency, demonstrating UC ANR's commitment to the public value of protecting California's natural resources.