Soybean Meal

I applied 19 lbs/1000ft2 Soybean Meal. Using 7-1-2 analysis, that should work out to 1.3-.19-.38 lbs actual per 1000 ft2. In my research, I saw somewhere that lawns need 4-1-2 lbs/1000ft2 actual a year. i can’t remember if that is a high maintenance lawn. My objective is to have a nice green lawn, but don’t want to have to cut it every 3 days and make a lot of applications, since 70,000 ft2 takes a bit of time. I am trying to feed the soil instead of the grass, so I guess my question is if I should try to supplement (probably map and potassium sulfate) to bring it up to recommended.