|Over many years and fields of sampling, we have learned a lot. Post
pollination nitrogen application is the only statistically significant nitrogen
application that correlates to yield. This is true over all fields and
those with the low pre plant nitrogen amounts.
observations from our data include a statistically significant cost savings from
not applying more than 50 #/ac of nitrogen with a herbicide carrier. A
larger application than this tends to drive nitrate levels very high in the
young corn plant. The plant cannot utilize all the nitrogen at once and in
effect results in "wasted" nitrogen as more has to be applied at a
later date. We have also seen the same from pre pollination applications
of UAN over 80 #/ac of nitrogen. The most cost effective application
combination in this case is a side dress application followed by UAN post
pollination. We have some fields with adequate soil nitrogen
that use no pre plant nitrogen, a small amount of herbicide carrier, and then
UAN both pre and post pollination. These fields do not require over 80
#/ac of nitrogen pre pollination, so UAN is the most cost effective
The chart below examines the effect of timming on yield and nitrogen use. It is based on our years of data.
key is monitoring the crop and managing the nitrogen. Better Harvest
specializes in just that.