ALBUQUERQUE — Farmer Don Bustos said the tradition of working the land in Northern New Mexico's Española Valley had been passed down from his Spanish ancestors who tilled the same soil centuries ago.

But when he realized the traditional farming techniques he was using could harm his children's health, he went organic 15 years ago. Now, Bustos said, he has found an even safer method: vegan organic farming without any animal fertilizers or byproducts.

Bustos was inspired to pursue vegan farming four years ago after hearing an address by then-U.S. Secretary of Agriculture Mike Johanns.

"He was talking about ways to protect the safety of our food system, but to me, you still have things like E. coli and salmonella from manure (fertilizer). I thought to myself, 'I'm not going to be putting that crap on my crops,' " Bustos said. "Now, I use no manures, no bone meals, blood meal, no pesticides, nothing."

This farming method, also called veganic or stock-free farming, is an emerging concept here in the United States.

Much like certified organic farmers, veganic farmers use no synthetic chemical fertilizers, pesticides, herbicides or genetically modified ingredients. But veganic farmers take their methods to another level by not using any manures or slaughterhouse byproducts. They don't even use organically approved pesticides.

Veganic farmers use crop rotations and composted plant matter — or "green manure" — to fertilize their crops.

Vegan farmers in the U.S. are motivated by the need to protect the environment and human health, said Ron Khosla, who operates the 77-acre vegan organic Huguenot Street Farm in New Paltz, N.Y., with his wife, Kate.

Khosla said the primary source of nutrients on many organic farms in the country comes from manure from confined animal operations, or what he calls "factory farms."

"You think you are getting these clean happy vegetables, but more often than not, they're grown in waste from factory farms," he said. "The animals ... were fed nonorganic feed laced with hormones and antibiotics. Those products bio-accumulate in the animals, and it's present in their waste as well."

Both Kholsa and Bustos said they have a strong customer base that seeks out their produce because of the vegan growing philosophy as well as a growing awareness about food production.

"Customers are becoming more aware about how their food is grown and the practices by the farmer who's growing it. It's the customers that are encouraging us to find ways to become more environmentally conscious and efficient," Bustos said.

Veganic growers say their methods reduce environmental impact by using less land, conserving water and producing fewer greenhouse gas emissions. "Veganic farming is not rocket science. It's only using techniques for farming that have been used for hundreds of years," Kate Khosla said.