For an experienced producer, it can be fairly easy to know when a corn field is nitrogen deficient. The yellowing of the lower leaves is a tell-tale sign that a corn plant is lacking nitrogen. In contrast, it is difficult to know if a corn crop is over fertilized or if fertilizer has been applied in excess of what the crop really needs. Many farmers and ag professionals are searching for a diagnostic tool that can improve nitrogen fertilizer management. The basal stalk nitrate test is one of these tools.
It is important to note this is a diagnostic, not a predictive, test. Results do not provide an absolute determination of under or over application. Rather, results from this test provide general management guidelines and help inform discussions about on-farm nutrient management.
In general, the basal stalk nitrate test estimates how much nitrogen is left over at the end of the growing season.
How it works
Producers are able to use this information to make nitrogen management changes that are appropriate for their farm. When possible, nitrogen management trials will be supported to evaluate changes (i.e. compare nitrogen rates) producers want to see in their field.
To learn more, read the University of Minnesota Extension's publication (PDF) regarding end of season basal stalk nitrate testing.
Impaired Waters Technical Adviser
Luke.Stuewe@state.mn.us ~ 218-846-7425