Courtesy of UC Agriculture and Natural Resources 

Additional guidance needed for groundwater management strategies 

Cover crops are planted to protect and improve the soil between annual crops such as tomatoes or between rows of tree and vine crops, but growers may be concerned about the water use of these plants that don’t generate income.

“Cover crops are one of the most popular practices we see farmers employ through our Healthy Soils Program,” said Karen Ross, secretary of the California Department of Food and Agriculture. “Cover crops supply a host of benefits, such as helping to protect against soil erosion, improving soil health, crowding out weeds, controlling pests and diseases, and increasing biodiversity; and they can bring increased profitability as the number of other inputs are reduced. They also provide water benefits such as improved infiltration and reduced runoff.”

These potential benefits are especially salient in the San Joaquin Valley, where groundwater challenges are more acute. A new report evaluates the water implications of cover cropping practices to lay the groundwork for their adoption in the context of the Sustainable Groundwater Management Act, or SGMA, which is intended to protect groundwater resources over the long-term.

“Yes, cover crops require a nominal amount of water to establish – and sometimes rainwater is sufficient – but the myriad co-benefits are worth it,” Ross said.

Growers, water resource planners and managers, crop consultants, irrigation practitioners and policymakers may find the cover crops report useful.

The report is the product of a convening process jointly developed by the California Association of Resource Conservation Districts, CDFA, Natural Resources Conservation Service of California, and University of California Agriculture and Natural Resources, and assembled by nonprofit Sustainable Conservation.

The multidisciplinary group of more than 30 individuals has published “Cover Cropping in the SGMA Era.” The literature review, policy analysis and recommendations pertain to the water impacts of cover crop practices in California’s Central Valley under SGMA.

Cover crops and their potential

“Wintertime rain-fed cover cropping does not necessarily significantly increase water losses compared to bare ground in the winter months,” said co-author Daniele Zaccaria, associate professor in agricultural water management for Cooperative Extension at UC Davis. “Cover cropping can significantly improve soil-water dynamics, increasing soil water infiltration and storage and reducing surface runoff.”

To reap the benefits of cover crops using minimal water, Zaccaria said growers will need to know how the plants perform under different conditions.

“We need to develop and implement a coordinated research effort to increase understanding of net water impacts of cover crops under various meteorological conditions – dry, wet, average,” he said.

Report findings and recommendations

To understand the potential of cover cropping under SGMA, the report’s authors came together to answer the following questions:

1. What are the impacts of cover crops on water cycles (both benefits and use)?
2. How does SGMA management account for cover cropping and is it capturing cover crop benefits alongside their water use?
3. How can we ensure that this practice remains available to growers where and when it makes sense?

This report synthesizes the learnings from the collaborative initiative including 100-plus multidisciplinary experts, a policy analysis, interviews with Groundwater Sustainability Agency (GSA) staff and consultants, and the expertise contributed by its 30-plus authors. In light of these findings, the report advances a series of recommendations aimed at bridging critical knowledge gaps, enhancing the integration of cover crops into policies and incentive programs, and bolstering data infrastructure and other mechanisms to support sustainable groundwater management initiatives.

One vital throughline is the need for additional guidance from the state to support local GSAs in facing the complex challenges of developing and implementing groundwater management strategies for their local watersheds. These measures aim to optimize cover crop integration within SGMA frameworks and promote sustainable water management practices crucial for the region’s agricultural resilience and environmental health.

“This report is unique because the university collaborated closely with state agencies and private sector partners to ensure that the different perspectives provided both the best science available as well as viable policy options,” said Glenda Humiston, University of California vice president for agriculture and natural resources. “By taking a comprehensive view, we can advance recommendations for cover crop policy that help us meet multiple goals, manage our natural resources more effectively, and avoid unintended consequences.”

Sarah Light, UC Cooperative Extension agronomy farm advisor, is one of the UC ANR experts who provided science-based information during the convening sessions and co-authored the white paper.

“Cover crops are a valuable soil health practice that can help ensure the resilience of California farms to climate extremes,” said Light. “As we balance the complexities of water and soil management, it is important to understand the role that cover crops play in an annual water budget so that they are not disincentivized in certain parts of the state. This paper can provide guidance to GSAs and policymakers who are charged with implementing SGMA in their regions.”

The report “Cover Cropping in the SGMA Era” can be downloaded for free at https://suscon.org/wp-content/uploads/2024/05/SC-Cover-Crop-SGMA-Report.pdf.

Courtesy of the UCANR News 

Although training is required to become a University of California Master Gardener, the benefits of gardening can be experienced by anyone and everyone.

“As long as you’re willing to get your hands dirty,” said Laurie Menosky, a UC Master Gardener volunteer in Orange County, “you can learn to grow all sorts of things.”

In early April, Menosky partnered with ETN Medical Infusion (a clinic in Orange County) and the Sustainability Program for Student Housing at UC Irvine to teach students how to grow tomatoes. Menosky welcomed all in attendance, including families with toddlers who seemed fascinated by the 60 tomato plants atop one of the tables in the room.

The UC Master Gardener Program is a part of UC Agriculture and Natural Resources. During her presentation, Menosky taught participants how to choose varieties that fit their taste and growing environment, how to cultivate a thriving environment, and how to control pests and diseases using integrated pest management practices.

“We have 16,000 residents at UCI and sustainability is one of our values. One of the ways we engage students is through on-campus gardens,” said Rachel Harvey, sustainability program manager for UCI Student Housing and a UC Master Gardener volunteer in Orange County.

UC Irvine has one teaching garden reserved for undergraduate learning, and three gardens operated and maintained by graduate students. “I was on the waiting list for a garden plot for a while, but it was totally worth the wait,” said Johanna Rinaman, a fifth-year Ph.D. student studying physical chemistry.

While the highlight of the event for many people was the opportunity to take a tomato plant home, another important takeaway was how gardening can be a good activity for your mental health. Sarah Nghiem, family medicine specialist at ETN Medical Infusion, who worked closely with Menosky, was instrumental in developing the mental health content for the day, encouraging attendees to attempt gardening with a mental health perspective.

Nghiem and her team received funding from the Orange County Health Care Agency through the Mental Health Services Act to work with transitional aged students (15-24 years-old) on understanding the importance of mental health, which led to the collaboration between UC Irvine, her alma mater, and the UC Master Gardeners of Orange County.

“I didn’t do any gardening during the winter, and I felt a lot more anxious and depressed during that time,” Rinaman said. “I know gardening improves mental health because I’ve immediately felt a difference whenever I spend time with plants.”

Rinaman, whose father taught her a lot of what she knows about gardening, said that having access to a 4 feet by 6 feet plot to grow her own food is one of the many things she loves about UC Irvine.

Like Rinaman, Menosky turns to gardening to decompress, especially during the long days of summer. Teaching others about the physical and mental benefits of gardening gives her an opportunity to share her experience and, hopefully, help others find new ways to manage stress.

“We often have attendees come back years later telling us how our information has helped them and how much more they are enjoying their time in their gardens,” she said.

To conclude her presentation, Menosky instructed participants to line up for their own tomato plant. Attendees took their plants outside to transfer them from a small pot to a grow bag – a type of container that helps root structure development.

Cassie Ekwego, a third-year transfer student studying civil engineering, couldn’t hide her excitement after carefully lifting her plant. “I don’t think I realized how attentive you need to be when working with plants,” said Ekwego, reflecting on what she learned from Menosky’s presentation.

Now that she has her own plant to care for in her own home, Ekwego is eager to put her new knowledge to the test. “I love tomatoes, but this is going to be a huge responsibility for me,” she said.

Randy Musser, UC Master Gardener program coordinator for Orange County, said that while he enjoys talking to avid gardeners, bringing gardening to new people in the community is special to him. “This tomato workshop is particularly exciting for me because it is an opportunity for the UC Master Gardeners to grow our connection to UCI and young people just starting off on their gardening journey,” said Musser.

With a generous contribution from UC Master Gardener volunteer Sheila Peterson, Musser was able to purchase enough supplies to help attendees, like Ekwego, jumpstart their gardening experience.

Students, whose stress levels can skyrocket throughout the school year, value opportunities to be outdoors, try something new and be in community. “The garden is a different type of classroom. It’s a place where students can learn and experiment, hopefully in a way that reduces stress,” said Harvey of UCI Student Housing.

Ekwego, who tried gardening for the first time while volunteering at UC Irvine’s teaching garden, is just one of the many students inspired by their experiences. “Gardening reminds me that it’s OK to get my hands dirty,” Ekwego said.

A new study that can help growers and other readers estimate costs and potential returns for blackberries grown on California’s Central Coast was recently released by UC Agriculture and Natural Resources, UC Cooperative Extension and the UC Davis Department of Agricultural and Resource Economics.

“The study provides growers with a baseline to estimate their own costs, which can help when applying for production loans, projecting labor costs, securing market arrangements or understanding costs associated with water and nutrient management and regulatory programs,” said Brittney Goodrich, UC Cooperative Extension specialist and study co-author.

The cost study models a management scenario for a 30-acre farm, 15 acres of which are planted to blackberries. The remaining acres are planted to other berries or are used for the irrigation system, roads and buildings. The authors describe the cultural practices used for the establishment, production and harvest of blackberries, including land preparation, soil fertility and pest management, irrigation and labor needs.      

The 28-page study shows costs for each operation, material inputs and costs, and cash and non-cash overhead costs in a variety of formats for an establishment year and then four additional production years. A ranging analysis for the four production years is also included and shows potential profits or losses over a range of prices and yields.

The new study, titled “2024 Sample Costs to Establish, Produce and Harvest Blackberries” can be downloaded from the UC Davis Department of Agricultural and Resource Economics website at https://coststudies.ucdavis.edu.  

For a detailed explanation of the assumptions and calculations used to estimate the costs and potential returns, readers can refer to the narrative portion of the study. 

Sample cost of production studies for many other commodities grown in California are also available on the website.

For more information, contact Mark Bolda, University of California Cooperative Extension farm advisor, at mpbolda@ucanr.edu or Jeremy Murdock in the UC Davis Department of Agricultural and Resource Economics at jmmurdock@ucdavis.edu.