Innovations in groundwater recharge

For the past several years, UC Davis hydrologist Helen Dahlke has worked with Cooperative Extension Agronomy and Nutrient Management Advisor Nick Clark and Khaled Bali, UCCE Irrigation Water Management Specialist, on groundwater recharge in alfalfa fields. They were introduced together by Cooperative Extension Specialist Dan Putnam and have been funded by UC ANR, California Institute of Water Resources, and USDA-ARS. The research and extension explores how alfalfa copes with additional water in the winter and early spring, when snowmelt runoff occurs, for groundwater recharge.

The findings have shown great promise for recharging groundwater without negatively impacting alfalfa yield but may diminish quality. Bali commented, “You could do recharge in winter and then turn the water off completely and still get a cutting or two of alfalfa before the summer.”

Clark emphasized that farmers face incredibly complex water management issues today, and the drivers that influence their decisions reach far beyond the farm scale. “It requires an approach from multiple disciplines to address that complexity,” he said. “Being able to work with Helen, who brings the hydrological expertise, while I can focus on the agronomy helped create a more balanced team, so the information we provided was more holistic and relevant on a larger scale, but still practical and applicable for farmers.”

In all her collaborations with farm advisors, Dahlke appreciates the guidance they provide when she is planning an experiment. “They have such a solid footing in the farming community that they already know what practices could work, which ones might be problematic, where there might be pushback,” she said. “And the grower trusts that farm advisor and I trust the farm advisor, and by relation the grower trusts me eventually, and that’s just golden,” she added.

Groundwater recharge study

Watch a short video about the collaboration

Grower input on the research findings has been critical to their success. “With that feedback we were able to reform some of the project methodologies to achieve results that were even more relevant to the local conditions,” said Clark.

Bali and Dahlke are also working with UCCE Farm Advisors Laura Snell and Larry Forero. They formed a group to explore winter recharge in Modoc County, and they have already done some recharge there through outreach to landowners. “These are the types of collaborations we want to see, and again, it would not be possible without farm advisors in those communities caring and then knowing what network of researchers they have at the campuses,” said Dahlke.

Agronomy and Crops Advisor Giuliano Carneiro Galdi is also working with Dahlke to address water management in Siskiyou County; they will begin a grant-funded winter recharge project in 2022. “She's teaching me how to sample water from groundwater or surface water and explaining how the flow of the water works here in Siskiyou County,” Galdi said. “She's been very helpful in this research and having been in the position for just two years, it’s been especially important.”

Dahlke, Clark, Bali and Galdi all stress the importance of networking for academics to find opportunities to collaborate. They recommend attending the UC ANR academic orientation meetings, attending trainings and workshops that ANR offers, reaching out to the extension specialists in their departments, and connecting early with ANR program teams and work groups as well as actively using the ANR directory.