When Andrew and Melissa Dunham took over a 150-year-old corn, soybean and cattle farm from a relative in 2006, the 80-acre spread northeast of Des Moines couldn’t support a full-time farmer.

So the young couple decided to overhaul the operation by embracing what was then a small but growing niche in agriculture — organic farming, now one of the hottest sectors in the multi-billion-dollar food industry.

Organic food sales have risen by double digits annually as the public consumes more fruits, vegetables, pastas, dairy and meats raised and grown without pesticides, genetic modification or antibiotics, among other stringent requirements. Over the past decade, organic food revenue has tripled, reaching a record $36 billion last year.

“Organic is much more mainstream now. More people are seeking it out,” said Andrew Dunham, who sells beef along with carrots, kale, cabbage and almost 60 other crops to Whole Foods, co-ops and farmers markets in Iowa. “We actually do end up saying ‘No’ quite a bit. We’re pretty much selling everything we grow now.”

Dunham said embracing organic has made it easier to get his produce and meats into grocery stores and attract customers seeking organic goods at farmers markets. The decision also has been a boon to the farm’s bottom line. The operation posted sales of around $400,000 last year, up 20 percent from two years earlier.

Their success has allowed the Dunhams to focus full-time on farming. Melissa quit her job in Minneapolis-St. Paul to work on the family operation.

“Demand (for organic) just keeps going up and up and up,” Andrew Dunham said.

A rising market

Despite organic farming’s booming growth, it remains less than 6 percent of the $630 billion in total supermarket sales in 2014 reported by Progressive Grocer Magazine.

But the industry’s growth isn’t expected to subside anytime soon, according to the Organic Trade Association. It predicts sales will increase 12 percent to 15 percent annually for the next three years.

That rapid growth has brought its own challenges to the industry — chief among them demand, which organic producers are struggling to meet.

Shortages have led to sky-high prices for some organic products. And more livestock producers, hungry for organic feeds, are importing them from overseas because they can’t find enough in the United States.

“There is not a major retailer in the country that doesn’t have appealing to the organic shopper in their strategy right now,” said Laura Batcha, executive director of the Organic Trade Association. “But what happens if the industry can’t fulfill that opportunity, and people walk away?”

It’s difficult to know how many new acres of organic crops will come into production, the industry concedes, because of incomplete data, competition for land in some areas and the three years it takes to earn certification as an organic farm.