Farm wife Sharlene Merk is encouraged by research findings that a cocktail of ground horseradish and hydrogen peroxide can cut the stench of hog manure.
From the door of her rural farmhouse in west Iowa, Merk can see two long blue buildings containing thousands of hogs on a neighboring farm. A second hog farm, with thousands more animals crammed into three white buildings, is less than half a mile away.
The 67-year-old Merk said the stink often makes her and her husband Leroy, 71, feel physically ill.
"A lot of times we simply have to leave home because it is so bad," she said.
When mixed with a manure slurry, the horseradish cocktail neutralizes the chemical compounds that comprise odor - substances called phenols, said Jerzy Dec, a senior research associate at Pennsylvania State University.
Dec said the horseradish mixture cut odor intensity as much as 50 percent - at least that's what the six people on the test panel said after sniffing the hog slurry, obtained from a university research farm.
The findings were confirmed through gas chromatography, which documents the chemical makeup of the air. It confirmed that 100 percent of odor-causing chemicals were neutralized for at least 72 hours.
"At least you have ... three days to go and dispose of your treated manure," Dec said.
The study, which appeared in the June 29 issue of the Journal of Agricultural and Food Chemistry, emerged from previous research that found that minced horseradish roots, potato tubers and white radish roots, combined with small amounts of hydrogen peroxide, removed phenols, including industrial contaminants, from water and soil.
Dec said the horseradish works because it contains large quantities of an enzyme that breaks down the phenols, which are formed from sugars.
The horseradish mixture is environmentally friendly and can be reused up to six times before having to be replaced, making it a cost-efficient option for farmers.
Horseradish prices are a little high, but "if this method catches on ... then the prices should drop dramatically," Dec said.
Dec said the discovery is important as factory farms continue to spread in Iowa, where hogs outnumber people 5-to-1, and in other rural states across the nation.