Farmers should use caution when using poultry litter as a source of fertilizer for tobacco to ensure that chloride levels aren’t too high.

“Basically, we’ve known for many years that chloride in high amounts is detrimental to cured leaf quality,” said Bob Pearce, University of Kentucky tobacco management specialist. “It can negatively affect the color, flavor and aroma and the rate of burn of tobacco products.”

Chloride in high amounts can act like a wick taking up and retaining moisture in the cured leaf resulting in fat stems, and can cause it to come too high in case relatively easily, he said.

Because of this knowledge, there is a law in Kentucky that limits the amount of chloride in commercial fertilizer that can be sold for use on tobacco.

With the influx of the poultry industry into Kentucky, litter has become available for farmers to use to fertilize their crops. Chloride levels are a quality issue unique to tobacco, Pearce noted.

A survey conducted by Frank Sikora, UK soil testing coordinator, has shown a wide range of chloride content in chicken litter with an average of about 2 percent, Pearce said. The current UK recommendation for use of chicken litter on tobacco is no more than four tons per acre.  However, even that may be too much.

Litter with a 2 percent chloride content at 30 percent moisture amounts to approximately 130 pounds of chloride per acre, more than double the recommended maximum of 50 pounds annually for tobacco, Pearce said.

Pearce, along with some of his students, is studying chloride’s effects on tobacco with 2002 being the first year of the project. He said he hopes within a couple of years to be able to revise the formal litter recommendations for use on tobacco.

For now, Pearce recommends that farmers be cautious when using litter on tobacco and suggests using a maximum of 2 tons per acre and to apply it in the fall. A fall application allows the chloride to leach out during the winter months reducing its possible negative impact on quality, but farmers should also be aware that fall application will result in some nitrogen loss.