Friday, August 22, 2008

Dry Forage Samples With a Hair Dryer

Ag Engineer Dennis Buckmaster has developed plans for building a simple homemade tool to determine moisture content of forage samples.

Buckmaster designed the dryer out of a standard home hair dryer and materials available at hardware stores. The homemade dryer is called a "Vortex Dryer", so named because a CPVC pipe is attached to a funnel- or vortex-shaped container made from two round duct reducers.

The Vortex Dryer is easy to use, requires less supervision when drying samples than the microwave oven method, and requires less time to dry samples than a Koster tester.

The Vortex Dryer also gives very accurate results. The error error was -0.1%. Moisture estimates were within 1% of the actual value 95% of the time. There was no statistical difference between the vortex dryer results and those obtained when using the standard drying oven method.

For more information on the Vortex Dryer, including how to build and use one, see the Penn State Extension Fact Sheet entitled "A Vortex Forage and Biomass Sample Dryer", available online at

The Vortex Dryer would be useful for checking forage moisture levels at harvest or feeding time. Earlier this week Bill Weiss alerted Ohio corn silage growers to check their corn for dry matter content, as it is likely to be ready for chopping. The Vortex Dryer would be very useful in determining the dry matter content of corn silage in each field.