You may like avail IF you have a high pH with a Very High Calcium level, and or if you have a calcareous soil with 6% to >10% Free Lime (Calcium Carbonate).  The free lime turns the phosphate to a rock phosphate in short order. 

 

If I need 17 units of P2O5 normally HERE I need to apply 71 units of P2O5 for the same result. BROADCAST. 

 

 

We can band the phsophate fertilizer that helps some.

 

WeI can deep band the phosphate fertilizer, down a pipe behind the pipe with anhydrous ammonia that helps a good bit.

 

If I were planning to  broadcast 800 lbs of Triple Super Phosphate prior to planting alfalfa, for sure, I would include some Avail !