Environmental Feasibility of DairyMAR

Researcher: Dr. Helen Dahlke, UC Davis Land, Air, and Water Resources
Timeline: January 2024 – December 2025

Background: Available water for recharge in 2023 exceeded 21 million acre-feet. Dairies manage about 430,000 acres of cropland and dairies in the Tulare Lake Basin have participated in DairyMAR (managed aquifer recharge on dairy-controlled, manure-managed cropland) to receive credit toward future groundwater pumping. The purpose of this project is to confirm that DairyMAR can be implemented without negative impacts to groundwater quality and to provide an initial assessment of the feasibility of DairyMAR under federal and state water quality protection constraints.

Industry Benefit: This research will further develop a foundational framework for the development of promising DairyMAR practice standards. A downstream impact of this project will be that the dairy industry could be able to augment the available water resources under the implementation of groundwater sustainability plans, leading to relatively larger forage and silage production than would otherwise be possible. This work could establish a foundation for the dairy industry to engage in California’s most promising expansion of water resources available to growers: managed aquifer recharge.

This will be the first U.S. project to investigate the groundwater quality impacts from DairyMAR that is from implementation of managed aquifer recharge on croplands managed with dairy manure as the main source of fertilizer. The ultimate economic impact would be the availability of additional water resources, which will lessen the need for land re-purposing of dairy crop acreage to meet water supply constraints in a changing climate and under the implementation of groundwater sustainability plans.