Posted 6/30/2020 11:14 (#8345207 - in reply to #8345175) Subject: RE: Top dress or not?
I think it depends on how much of the pre plant applied nitrogen is still there, if it was applied to right before planting and you haven't had tons of rain the I would think that would be sufficient. 164 lb applied plus 60-90lb from organic matter mineralization should be enough for 200bu + corn according to the calculator I looked at.
Now if you applied it back in April or May and had the rain that we had here then I would bet some has gone.
Seems like it might be a good time to try a pre sidedress nitrate test.