Still, many farmers and scientists remain unpersuaded. Mr. Chapman, of the Real Organic Project, served on a U.S. Department of Agriculture hydroponics task force five years ago, and is leading an effort to get the agency to stop allowing hydroponic farmers to certify their produce as organic. The very definition of organic farming, he and others say, rests on building healthy soil. In May, the Center for Food Safety, an environmental advocacy group, led an appeal of a federal court ruling that upheld the agency’s policy.
Although the nutritional profile of hydroponic produce continues to improve, no one yet knows what kind of long-term health impact fruits and vegetables grown without soil will have. No matter how many nutrients indoor farmers put into the water, critics insist that indoor farms can never match the taste and nutritional value, or provide the environmental advantages, that come from the marriage of sun, a healthy soil microbiome and plant biology found on well-run organic farms.
“What will the health outcomes be in two generations?” Mr. Chapman asked. “It’s a huge live experiment, and we are the rats.”
The divide between soil loyalists and ag-tech futurists is playing out on a much more intimate scale between two influential brothers: Dan and David Barber, who founded and own the organic farm Blue Hill and its restaurants in Greenwich Village and at Stone Barns in Pocantico Hills, N.Y.
In 2018, David Barber created an investment fund to support new food tech companies, including Bowery. But Dan Barber, a chef whose 2014 book “The Third Plate: Field Notes on the Future of Food” devotes an entire section to soil, believes that truly delicious food can come only from the earth.
“I am not buying any of it,” Dan Barber said of the hydroponic fever.