Great question, DJT. Checking my records, I was actually surprised that my feeding season last over 6 months every year, and that I'd better get a couple bags of feed in the next week to get started on time (I may actually be late this year, if my new YP eat earlier than the BG/LMB/CC).
Anyway, for2007 (the last year I can remember exactly how much feed I bought),, I fed 150 pounds of GFC and 150 pounds of Aquamax 600 in 0.9 acre. Figuring an effective 6 month long feeding season (it's more like 6.5 months, but they feed not so much at either end), I fed 55.6 pounds/acre/month.
Of course Theo is probably going to muck this formula up by throwing in an azimuth calculation or something.
That's
Latitude, Bean Counter.