Extension News

New Publication Explains Meaning of Grain Test Weight, Unravels Misconceptions


AMES, Iowa – With harvest season coming to a close, Iowa State University Extension hopes to clear up misconceptions about grain test weight for farmers working to market and sell their corn. A new ISU Extension publication, “Grain Test Weight Deceptions,” PMR 1005, discusses the purpose for grain test weight, how it can be used to determine grain value and how calculations can be deceptive.


Deception often occurs when one believes that an increase in test weight equals an increase in the weight of grain sold, but this is not true. Instead, test weight is a measure of grain quality and density.


According to the publication, prepared by ISU agricultural and biosystems engineering faculty, increased test weight simply means the corn occupies less total volume because of greater bulk density. However, at sale, one bushel of corn is 56 pounds regardless of test weight.


Test weight can affect the price a seller receives. Additionally, drying methods can increase test weight, and there are various methods of drying that produce different results.


These things are discussed more in-depth in the publication, which was prepared by Carl Bern, professor of agricultural and biosystems engineering and Thomas J. Brumm, associate professor of agricultural and biosystems engineering. It is free to download from the ISU Extension online store, www.extension.iastate.edu/store/. Enter PMR 1005 in the search box to find the publication.



Contacts :

Carl Bern, Agricultural and Biosystems Engineering, (515) 294-1270, cjbern@iastate.edu

Thomas J. Brumm, Agricultural and Biosystems Engineering, (515) 294-5145, tbrumm@iastate.edu

Hannah McCulloh, Extension Communications and External Relations, (515) 294-9915, hmac@iastate.edu

Laura Sternweis, Extension Communications and External Relations, (515) 294-0775, lsternwe@iastate.edu