The end-of-season cornstalk test is a good tool for evaluating nitrogen (N) management practices used in any corn field in any year. The test is most valuable when used on field that show no visual signs of N deficiency. Stalk Nitrate Brochure, Aug, 2017.
The key here, is that your sample should be collected and sent to the laboratory within a 24 hour period. This analysis can experience a lot of variability if the sample is collected and it sits around for days. To help with this process, Midwest Laboratories is providing Stalk Nitrate bags that are much easier to use in the field than paper bags. Many articles indicate that plastic should not be used. Most of this information was written 15-20 years ago when transporting samples was an issue and for that reason plastic was highly discouraged. Today, growers are in their fields on a regular basis and use the advances with shipping technology to send samples to a lab in a more efficient manner.
Learn more about this analysis on the Midwest Labs Stalk Nitrate Page.
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