Wisconsin is the nation’s largest producer of green beans, carrots, red beets and lima beans, and the state ranks third in the U.S. for potato production, according to the Wisconsin Potato and Vegetable Growers Association.

All the crops from that $6.4 billion industry need water — and lots of it — and because the crops in the state’s Central Sands growing area are irrigated with water from an extensive aquifer that lies under several counties, there was a great deal of concern when water levels in parts of the aquifer declined.

Five years after the WPVGA formed a groundwater task force to foster the sustainable use of water resources, the outlook is improving.

“We’ve learned we can irrigate more efficiently,” said Jeff Wyman, program specialist for the Wisconsin Institute for Sustainable Agriculture.

Growers in the Central Sands area monitor roughly 500 high-capacity wells at least twice a year. Wyman said water levels in those wells drop several inches to a foot and a half during the growing season but are replenished by rain and snow in the fall and winter. Wyman said this spring many of the wells had higher water levels than at the same time last year.

“We’re encouraged,” Wyman said.

The groundwater task force has representation not only from more than a dozen potato and vegetable growers but also potato and vegetable processors, rural communities, University of Wisconsin researchers, the Wisconsin Geological and Natural History Survey, the Wisconsin Institute for Sustainable Agriculture, USDA and others.

Two years after the task force was formed, the WPVGA took things a step further when the association and the Midwest Food Processors Association raised more than $600,000 in matching funds to land a USDA grant to examine ways to use water more efficiently. Research for the three-year study is expected to be complete by September, Wyman said.

Soil moisture monitoring has given growers new ways to determine when crops actually need water and devise a new irrigation scheduling program that allows growers to avoid waste. Wyman said the original irrigation schedule was based on potatoes, but new systems are being developed to precisely match the water needs of other crops so that the schedule can be expanded throughout Wisconsin and to other states.

The study also has been evaluating deferred irrigation, a system in which water is withheld from crops in the early stages of growth to promote deeper rooting. Wyman said the method uses one-third less water without adversely impacting yield or quality.

Wyman said deferred irrigation works well with soybeans and field corn, and researchers now are analyzing its use on shorter season crops, including snap beans, sweet corn and multiple varieties of potatoes.

“It’s a tricky thing, especially short-season crops,” he said. “If you’re off by a few days, you could mess up the whole deal.”

Wyman said findings of the project likely will be the subject of grower education sessions the WPVGA will offer in February in Stevens Point.