Special Report

Nitrate Toxicity in Drought Stressed Corn

Harvest of corn for silage will be occurring within the next week.  Concerns are that we may have nitrate toxicity problems in the corn due to droughty conditions in many areas.  Most nitrates accumulate in the lower 1/3 of the corn stalk.  Raising the cutter bar 6 to 8 inches higher than normal will greatly reduce the potential of high nitrates in green chopped silage for feed.  Normally, the ensilaging process (three to four weeks) will eliminate any nitrate problems in the feed.  Additionally, the rainfall prior to harvest  will help to alleviate concerns of nitrate problems in the corn. The corn plant (with the additional moisture) will mobilize the accumulated nitrates (lower stalk) to the leaves or developing grain where it will then be converted into amino acids.

When in doubt, send a sample to a lab for testing.

For more detailed information on nitrate problem in feed, refer to the following websites:

Kansas State University http://www.oznet.ksu.edu/library/crpsl2/MF1018.PDF

Michigan State University http://www.msue.msu.edu/ipm/CAT01_field/FC08-13-01.htm

Todd Vagts
Iowa State University Extension
Field Crops Specialist
1240 D. Heires Avenue 
Carroll, IA 51401 
Office: 712-792-2364; Cell: 712-249-6025;  Fax: 712-792-2366
Email: vagts@iastate.edu  

For questions or comments please respond to vagts@iastate.edu

This page last updated on 07/21/03