Nutrient Management Minute #75
Week of May 20, 2002 (June 17 kill date)
John Creswell, Coordinator
Nutrient Management Education Project
Iowa State University Extension
Late-Spring Nitrogen Test
This is John Creswell for Iowa State University Extension with a Nutrient
Management Minute.
This week, we’ll talk about the late-spring nitrogen test.
The late-spring nitrogen test can help you estimate the additional amount of
nitrogen your corn crop needs this season. To use the test, sample the top
12 inches of soil when the corn is between six and twelve inches tall. Then
immediately send samples to a commercial laboratory for nitrate analysis.
Test results will help you decide if there is enough nitrogen to optimize corn
yields, or if you need to apply more nitrogen. It can help you reduce
production costs, and also reduce nitrogen in surface waters.
To learn more about the late-spring nitrogen test, call your county Extension
office for a copy of publication PM-1714, Nitrogen Fertilizer
Recommendations for Corn in Iowa.
This has been John Creswell for Iowa State University Extension with a
Nutrient Management Minute.