I do not think Montag makes a 36 outlet box and I do not know of any way to put a 2x2 frame mounted dry (or liquid) fertilizer opener on a Bauer bar planter with JD or any brand planter row units.

My suggestion would be to set up a separate DB90 toolbar with our 6000 openers and put down the fertilizer in a separate 90 ft wide pass. Not what you wanted to hear I am sure. On a 90 ft planter when it is time to  plant you want to keep that planter rolling not filling fertilizer nor trying to find where along a 45 ft hose there is a plugged line, etc.

Or set up a 60 ft fertilizer bar (as shown here) to run ahead of your 90 ft planter. The 6000 will generally let you run at least 1.5 times planting speed so generally no problem staying ahead of the planter.

There is generally a much wider time window in the spring to get the fertilizer applied than an optimum time window to plant, especially if you have the acres and terrain to support a 90 ft planter. And with RTK on good terrain you can get almost the same 2x2 accuracy that you can on the planter. Side benefit is that your planter is not carrying corrosive fertilizer also. jmho

Jim at Dawn

edit: "2x2" generally means 2" to the side of the seed and 2" below THE SEED.

Then if we are planting corn 2" deep, 2x2 fertilzer placement is 2" to the side and 4" DEEP.

Trying to place any type opener 4" deep it should be mounted to the toolbar frame, NOT to the planter row unit in my opinion. Maintaining a fertilizer opener 4" deep in most soil conditions puts a lot of extra and random loads into the row unit and its frame, linkage etc. There is almost always some sacrifice in seed depth control which can be costly if not obvious. There is also very accelerated row unit etc wear.  "2x2" fertilizer openers must, in my opinion, be toolbar mounted, not planter row unit mounted. (unless you are in potting soil). jmho.

Jim at Dawn