mop has a lot of chlorine in it and that is what probably what happened to your "6 inch" test. try a small plot (use a spreader) and put 1/2 lb per 1000.
recheck your soil sample recommendations. I had a guy try to tell me his soil sample said to put 4 lbs of N per 1000 sq ft. I tried to tell him that had to be for the whole yr (st. aug)