A field study conducted by University of Illinois Extension researchers showed that mixing sawdust with hog slurry controlled odor and added organic matter once applied to cropland over a two-year period.

During the study, 50 gallons of slurry were mixed with each cubic yard of sawdust, creating a compost mixture with about 50 percent moisture. Researchers then used a bucket tractor to make four piles, roughly 4 feet high, 15 feet wide and 20 feet long on the producer's land. The product was left to compost naturally.

After five months, researchers took samples from each pile. Soluble salt, nitrate and pH levels were all within acceptable ranges. Also, the heat that's naturally produced during composting killed most of the Salmonella and E. coli bacteria.

Researchers applied the compost to sandy soils with low organic matter 13 months after composting began. Compost application equaled a high rate of 30 tons per acre and a low rate of 15 tons per acre. Organic matter was 1 percent to 2 percent higher in the manure-treated plots vs. those in the control plots. The compost had significantly increased the amount of organic matter in the top 5 inches of the soil.