A federal judge in Southern Oregon has rejected a request by two alfalfa farms to block Jackson County's ban on genetically engineered crops.

The decision by U.S. Magistrate Judge Mark Clarke following a hearing last week in Medford could allow the ordinance to take effect in June. Clarke found that the GMO ban is not pre-empted by Oregon's "right to farm" law. He said the "right to farm" measure prohibits ordinances and lawsuits that treat a common farming practice as a trespass or nuisance, but the law does not protect activities that harm commercial agriculture.

The Capital Press reports that Clarke also found that state lawmakers intended to permit the county's GMO ban when they excluded Jackson County from a 2013 bill that pre-empted other local governments from regulating biotech crops.

Some farmers and others are concerned about possible cross-pollination between biotech crops and those that are conventional or organic.

While Clarke dismissed the farmers' arguments regarding "right to farm," their claim seeking $4.2 million in compensation from Jackson County remains alive.