Boulder County commissioners on Thursday directed county staff to draft a plan for phasing out the growing of genetically engineered crops on county-owned farmland.

The county’s current cropland policy, which allows its tenant farmers to grow certain varieties of genetically modified corn and sugar beets on land they’re leasing from Boulder County, remains in effect at least through the end of this year.

But that policy, adopted in December 2011, has drawn fire from individuals and groups challenging the safety and impact of genetically modified organisms, or GMOs, on human health, water, soils and the environment in general.

Conventional farmers now leasing those county lands have argued that GMO crops are safe, reduce the amounts of pesticides applied and water used, and increase productivity.

On Thursday evening, the Board of County Commissioners didn’t take a formal vote. But their discussion indicated that an eventual plan for transitioning away from GMO crops on county lands will probably gain support of at least two of the three commissioners, Deb Gardner and Elise Jones.

Jones said the nearly 1,180 total acres of leased-from-the-county land now used to grow GMO crops annually could be phased out of those kinds of crops over a three-to-five-year period.

Gardner said the transition “should happen in close partnership with the farmers leasing the land” and may have to be done “on a field-by-field” basis.

Commissioner Cindy Domenico stated her support for a 5-3 vote by Parks and Open Space Advisory Committee members on Tuesday to continue the current cropland policy that permits GMO corn and sugar beets.

But Domenico — who was one of the three commissioners voting unanimously for the current limited-GMOs policy in 2011 — noted that she appeared to be in the minority on the present board.

If there has to be a phasing out of GMOs, Domenico said, she’d rather that it be done over a five- to seven-year period instead of three to five.

A number of supporters and opponents of the current policy allowing GMO crops sat in the board’s downtown Boulder meeting room as the commissioners gave lengthy presentations about how each had reached her policy positions.

Dan Lisco, president of the Farmers Alliance for Integrated Resources — an organization whose members include many of the tenant farmers leasing county lands as well as farming their families’ privately owned lands — said afterward that he was disappointed in the commissioners’ decision because “science supports that GMOs are safe,” and that GMO crop production uses fewer pesticides than even organic farming.

Lisco also said the tenant farmers may be looking into possible “legal remedies” to any forthcoming county action to ban GMOs. He said that might violate the terms of at least some of the farmers’ leases with the county.

But Richard Andrews, a former organic farmer who’s been fighting for years against the county allowing GMO crops on its lands, said, “I’m obviously pleased that they took the right path.”

Andrews said, though, that he’s a “little concerned” that the commissioners were discussing such a long multi-year transition period before eliminating the growing of those crops on county-owned lands.

Jones said she didn’t believe that foods consumed from GMO crops are “an automatic risk to human health,” but said she had “significant concerns” about the impacts of “toxic pesticides” that GMO crop systems require for weed control.

Gardner said her concern “is not with genetic engineering per se,” but about “the consequence of making crops resistant to applications of toxic pesticides like glyphosate.”

Domenico, however, said that after studying all the information she’s received about the GMO issue, “I am persuaded by the scientific literature and the scientists that state that biotechnology benefits outweigh the risks.”

The commissioners did not set a specific deadline for the Parks and Open Space Department’s agriculture staff to report back with a draft plan for phasing out GMOs.

John Fryar: 303-684-5211, jfryar@times-call.com or twitter.com/jfryartc