Measuring Dust on Feedlots

If you need to borrow a kitchen blender, make sure you don't use the one belonging to Agricultural Research Service's Daniel N. Miller. That's because he uses his slightly modified blender to pulverize soil from cattle feedlots so he can measure the dust produced.

Miller is a microbiologist at ARS' Roman L. Hruska U.S. Meat Animal Research Center in Clay Center, Neb. He and ARS agricultural engineer Bryan L. Woodbury are trying to determine the amount of dust produced in various sections of feedlots and why significant differences exist.

Dust can be inhaled into the lungs of both humans and animals and thus cause respiratory problems. Dust is also a carrier for odors, as well as ammonia and microorganisms.

The soil is first dried to remove excess moisture and then screened through a sieve. After the scientists put the soil sample into the blender, they turn it on for a series of blends totaling one minute. They collect the dust on a round filter that looks similar to fiberglass insulation.

They've verified that areas with a lot of moisture—which usually comes from rain, urine or water a farmer adds—have less dust. They've also gained new insights into the role of organic matter in dust production. Areas with greater amounts of dried manure actually needed more moisture to control dust than low-manure areas. Furthermore, they found that even small increases in moisture transformed dust-producing soil into soil that didn't produce dust.

In the future, the researchers want to look at other characteristics of dust, such as odor compounds bound to dust particles. They also want to look at other types of dust control besides adding sprinklers to the feedlot.

This research is reported in the September/October issue of the Journal of Environmental Quality.

ARS is the U.S. Department of Agriculture's chief scientific research agency.