I've been seeing more and more major P deficiencys on some new sites around here. Like 5 lbs or less / A. What's the maximum rate I should apply P / 1000 sq ft for surface applications? When feasible I'm core aerating before application but can't do this on all propertys. Soil test recommendations suggest 4 # P per year just for maintenance, and I'll probably overseed this fall too. One property I just aerated and seeded a few weeks ago. Right now I'm using 11-52-0 (MAP) to raise the P (at around 4#/1000). I'll probably use some 18-46-0 (DAP) this fall if my supplier has it. What are your thoughts?