ORIGINAL: psandhu
Someone will end up richer and someone else will end up wiser if you buy the P in 4 pound bags.
You need 25 lbs of actual P for your 1/4 acre plot. There is about 3/4's of a pound of P in the 4 pound bag of SuperPhosphate. That means you'll need 33 bags of the stuff. How much is it per bag, a couple of bucks? Multiply a couple of bucks by 33.
Buy your P from a grain elevator/fertilizer dealer. You should be able to get a 5 gallon bucket of DAP for less than $15. A 5 gallon bucket of DAP will have over 25 pounds of actual P in it.
Tip: You'll have to supply your own bucket when you buy the DAP.
All I have been able to locate in my area as far as Phosphorus goes is the Super Phosphate. There's another store that has a 50lbs bag of it and he said itis 0-46-0. Would that be sufficientfor my 1/4 acre plot? He also said he could get the potassium in 0-0-60. That should be fine right?