SACRAMENTO (CBS SF) — California’s Central Valley has some of the worst air quality in the nation but it turns out we may have been wrong about the source.

Beyond what comes from the automobile tailpipe, researchers at UC Davis point a finger of blame at the soil that grows our crops.

In a study published last week, UC researchers say smog-forming nitrogen oxides (molecular abbreviation: NOx) are released from the heavily-fertilized farmland in the Central Valley.

The research indicates that fertilizer is responsible for up to 41 percent of the NOx in the valley — much higher than previous studies have showed.

“In California it was an unrecognized source. So the farmers were not aware of it — people were not aware of it — and the state agencies were not really aware of this source of NOx,” said Dr. Benjamin Houlton, senior author of the study and a professor with the UC Davis Department of Land, Air and Water Resources.

Scientists hope their research can be used by lawmakers to reduce smog and improve air quality over much of California.

“The only way to tackle these environmental issues that involve agriculture is to work with farmers. It is really our hope … the state, researchers and farmers come together and work proactively on the issues,” the study’s lead author, Dr. Maya Almaraz, told KPIX.

Comments (2)
  1. James Bowen says:

    Research used by lawmakers to do what? Tax, fine and otherwise run farmers out of the state and/or pass it on to the consumer. They’re already trying to take methane out of manure at the expensive of dairy farmers. Kind of hard to make fertilizer without it. Less fertilizer means less crops and less food, which will drive up the prices. What a fantastic state we live in!

  2. Sharon Har says:

    Applying fertilizer just before a light rain is thought to prevent most of the evaporation into the air. This finding may result in more small family farms that can’t afford a dedicated person to deal with regulators going out of business.