ARS News Service
Agricultural Research Service, USDA
David Elstein, (301) 504-1654, delstein@ars.usda.gov
January 9, 2004 

Cleaning soil from plant roots before studying them would be easier and faster using a new washing device developed by Agricultural Research Service scientists.

Agronomists, plant pathologists, botanists and other researchers study the effects of soil and crop management practices on crop root systems. To examine plant roots, scientists usually have to spend time and energy cleaning them first.

Now ARS soil scientist Joseph G. Benjamin, at the agency's Central Great Plains Research Station in Akron, Colo., has created a root washer with a rotary design to automate and speed up the process. Other devices require more attention from the operator. The new device can clean up to 24 samples at a time, more than other washers.

The washing cycle starts when a technician places a soil sample--including roots--in the machine. As the samples rotate inside, they are dipped into water and then sprayed with water to remove the soil. Mud goes out the back of the machine as the roots are constantly washed. The cycle takes about one and a half hours to complete. The undamaged roots are then ready to study.

After the roots are cleaned, a flat-bed scanner digitizes root images so scientists can analyze the samples using computer software. Through mathematical equations, Benjamin determines the surface area of roots in the samples.

Benjamin's root washer is an enlarged version of the weed-seed washer invented by weed scientist Lori J. Wiles and others in the ARS Water Management Research Unit, Fort Collins, Colo.

More information about this research is available in the January issue of Agricultural Research magazine, available online at: http://www.ars.usda.gov/is/AR/archive/jan04/roots0104.htm

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