American consumers' demand for chemical-free and locally produced food has caused a surge in the number of organic operations across the county, new figures show.

The U.S. Department of Agriculture reported Monday that the number of certified organic producers jumped by almost 12 percent from 2014 to 2015 -- the highest rate increase since 2008.

"A powerful local and regional food movement is growing inside the United States," Agriculture Secretary Tom Vilsack wrote in a lengthy post Monday on Medium, "a movement that directly connects consumers with how, where and by whom their food is grown."

Vilsack called organic food "one of the fasting growing segments of American agriculture."

Thomas Barwick via Getty Images The U.S. has certified 21,781 organic growers since 2002, according to the USDA.

The U.S. has 21,781 certified organic growers -- 300 percent more than in 2002, when the USDA's Agricultural Marketing Service began keeping track, the federal agency said in a release. Worldwide, there are more than 31,000 certified organic operations.

The United States' organic retail market is worth more than $39 billion, up from $35 billion two years prior. In 2014, organic food represented about 5 percent of the nation's total sales -- up from 1 percent in 1997, according to a survey by the Organic Trade Association.

Laura Batcha, CEO and executive director of OTA, told Agri-Pulse the USDA's numbers reflected their own research. "Organic certifiers are getting more calls from farmers who want to go organic,” she told the publication.

A growing number of American consumers are also interested in locally sourced foods. In 2014, local food sales totaled at least $12 billion, compared to just $5 billion six years prior, USDA figures show.

ColorBlind via Getty Images The USDA figures showing a surge in the number of organic operations seem reflect a demand from American consumers to know what is in their food.

The agriculture debate today often pits organic products against those that have been genetically engineered. Genetically modified organisms, or GMOs, are often developed for their resistance to pesticides, allowing farmers to use more pesticides on their crops. But pesticides have come under increased scrutiny in recent years from those concerned about their safety and environmental impact.

The Associated Press found in a recent poll that 66 percent of Americans support mandatory labels for food products containing GMOs, while only 7 percent were opposed to the idea.

Several major food producers, including Mars and General Mills, have already begun voluntarily labelling products containing GMOs, and a Vermont law will soon require all genetically engineered food sold in the state to be labeled.

The nation's growing organic sector seems to be just the latest data point illustrating a national trend: Increasingly, Americans want to know what is in -- and on -- their food.