Let me know if my math is wrong but I think you are applying over 2lbs of N/k
200lbs of 46-0-0 x.46 equals 92lbs N divided by 300gal equals .307lbs N/gal X7gal/k equals 2.149/k.
I don't do liquid fert but isnt 2lb/k if N high
MDA no. 29204 (3-C)(6)