Late Season Cornstalk Nitrate
management is one of the most challenging areas in corn
production because of the many factors that influence N
availability including: form of N applied, timing of
application, impact of weather, etc. This is especially true when manure is part of the system.
Standard N recommendations take into account many of
these variables and early in-season tests such as the Pre-sidedress
Soil Nitrate Test (PSNT) and Chlorophyll Meter test are very
helpful in reducing the uncertainty in N recommendations.
While this uncertainty can never be completely
eliminated, it can be minimized.
A key to improving N management over time is having
reliable feedback on how well your N management program is
working. While good
yields and dark green plants are clear indicators of adequate
N, they do not tell you if you have too much N which can
especially be a problem for fields to which manure has
been applied. Similarly, visual symptoms of N deficiency may be observed
late in the season, but they are not always associated with decreased crop yields.
Season Cornstalk Nitrate Test has been demonstrated to be a
reliable end-of-season indicator of crop N status based on
research performed throughout PA as well as other states. It
provides a good assessment of whether the crop had the right
amount of N or too much N or whether it ran out of gas. This
information combined with records of N management can be very
useful for making future management decisions.
While you could test all fields, testing a few
representative fields will probably be adequate to provide a
good assessment of your N program.
this test, print the submission form and sampling instructions
from this site. Sampling instructions should be followed
carefully. Send the completed submission form and samples
with payment to the Agricultural Analytical Services
Cornstalk Nitrate Test