I apply prior to planting roughly half of the P, & K I think will be needed for the life of the stand. This usually carries me through a 5 or 6 year stand. If this is much phosphate then I kick in some zinc.
It is not unusual for me to use a fourth of a sack of borax per acre at this time.
Now a sack of copper sulfate will cover 4 acres for sure and usually 8 acres. Add to this a half pound to a full pound of Moly to the entire mix. Reasoning is copper and Moly work in opposite directions and if I apply one I need to apply the other.

Nothing scientific, I make a WAG based on a tissue analysis the final season of the previous alfalfa stand. I also use tissue analysis the first year back in alfalfa for any adjustments needed after my WAG.

Lesson learned. Do not apply more than 500 lbs of 0-0-60. If more is needed use split applications and or top dressing. I usually also apply 500, 1000, 1500, or 2000/A of K-Mag 0-0-22K-11Mg-22S. I like to apply the borax with these dry fertilizers.

I deep band/inject 100 to 1,000 lbs/A of 11-37-0. I tank mix with this any Zn, Cu, and or Mo.

To put this in perspective. My soil has an 8 pH. It will have from 4% to 8% free lime. The measured CEC will usually be between 40 & 50 meq.100g.

If I were in Ohio I would do it differently.