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Evaluating your nitrogen (N) management practices used in cornfields with a fall cornstalk nitrate test from SGS gives you an inexpensive and unbiased report on the N-practices used.  Thoughtful use of this test for several consecutive years can help producers compare alternative N management practices, avoid those that work poorly, and adopt those that work best.  Test results can help to optimize fertilizer placement within a field and minimize costs.

The fall cornstalk nitrate test is based on the fact that, during the grain-filling period, corn plants suffering from inadequate N remove nitrate from the lower cornstalks while corn plants having extra N accumulate nitrate in their lower stalks.  The concentration of nitrate in the stalk at the end of the season reflects all factors that influence N availability and N needs during the growing season. 

Sampling Procedures

  • Sample for stalk nitrates between one and three weeks after black layer of most kernels on most ears. 
  • Sample the 8-inch segment of stalk found between 6 and 14 inches above the soil surface. 
  • Remove leaf sheaths from the segments.  Do not use barren stalks or stalks severely damaged by disease or insects.
  • Within an area not larger than 10 acres, randomly collect fifteen 8 inch segments to form a single sample to be sent for analysis.  Sample areas differing in soil type or management histories separately.  Collecting one composite sample from each of several small areas (less than an acre) that seem to be representative of larger areas within a field is an effective strategy.
  • To reduce stalk mold, ship stalks immediately to the laboratory in paper bags or onion sacks, and placed in cardboard boxes.

For more information on fall cornstalk nitrate testing, please contact:

Neil Stoller
Agronomist, CCA/TSP
117 E. Main Street
Toulon, IL 61483
t: +1-309-286-2761
f: +1-309-286-6251