Santa Cruz County will test whether steam can replace chemical soil fumigants in berry fields, a move aimed at reducing pesticide use near schools and other community locations while exploring a more sustainable way to control pests.

A field is treated with steam fumigation in an undated image. Santa Cruz County will begin testing steam as a sustainable replacement for chemical fumigants on berry crops near populated areas. (Santa Cruz County Agricultural Commissioner’s Office)

The $175,000 pilot project, funded by the California Department of Pesticide Regulation, will begin this summer in the Pajaro Valley, where several berry growers will use high-temperature steam to treat soil before planting instead of conventional pre-plant fumigation. The research will continue into 2027, county officials said in a statement Thursday.

The pilot, led by the Santa Cruz County agricultural commissioner, grew out of discussions with community groups seeking alternatives to fumigants near sensitive locations, including schools.

Steam treatment works by injecting high-temperature steam into the soil before planting. The heat helps reduce soil-borne pests, plant diseases, nematodes and weed seeds without using conventional fumigants, according to county officials.

Test fields will be selected based on their proximity to schools and other community sites.

A recent independent study commissioned by the Department of Pesticide Regulation found that no existing alternative can currently replace chemical fumigants on a broad scale, and called for more research into where other methods may be effective.

“We’re pleased to support this collaborative effort by helping inform the public, facilitating community engagement, and contributing to the evaluation of a promising technology in sustainable pest management.”
David Sanford, Santa Cruz County Agricultural Commissioner

“This project provides an opportunity to further assess soil steaming as a potential alternative to conventional pre-plant soil fumigation,” Santa Cruz County Agricultural Commissioner David Sanford said. “We’re pleased to support this collaborative effort by helping inform the public, facilitating community engagement, and contributing to the evaluation of a promising technology in sustainable pest management.”

County officials plan to hold community outreach meetings throughout the pilot so residents can ask questions and provide feedback. The first meeting is scheduled for 5:30 p.m. on Aug. 18 at the South County Government Center in Watsonville.