Most field burning in the Willamette Valley will be banned starting next year, the legislature has decided.

The House voted 31-29 today to adopt Senate Bill 528, which cuts the maximum allowed burning area to 20,000 acres this year and bans the practice starting in 2010.

The only exceptions are for steep terrain in the Silverton hills and for disease outbreaks that can't be managed any other way.

Rep. Andy Olson, R-Albany, opposed the bill on the floor. He pointed to Nebraska, which had an unemployment rate in May of only 4.4 percent based on the strength of supporting agriculture.

Oregon's jobless rate was more than 12 percent in May, and in Linn County, the heart of Oregon's grass-seed industry, it was more than 16 percent.

Olson feared the ban would harm farming at a time when other sectors such as tourism, timber and high tech already are suffering.

Rep. Sara Gelser, D-Corvallis, spoke for the bill, saying that field burns under power lines had caused electric outages at Hewlett-Packard in Corvallis, a vital part of the mid-valley economy.

Rep. Phil Barnhart, D-Eugene, whose district includes south Linn County, urged approval of the ban.

Senate Bill 528's supporters say the bill is needed to protect the health of people on the east side of the valley who sometimes get hit when unforeseen weather changes cause field smoke to hover near the ground in towns such as Lebanon, Sweet Home and Lyons.

Olson distributed an analysis by Oregon State University showing that farmers may lose money on annual ryegrass if they are not allowed to burn at all. The analysis showed that the additional costs of baling the straw, flailing the stubble, applying herbicide and pesticide, and additional tillage raise the cost of raising annual ryegrass to the point where farmers lose money on every acre farmed.

The burn ban was the last major items of legislative business before adjournment either today or Tuesday.