Some ideas and concerns:
Hydraulic would be probably the most effective way. If the tractor is a 4010 and you are already using both remotes, you could rig in an extra circuit much like some of the discussions on here about mounting loaders.
You would need two motors one for each side.
A PTO powered hyd pump may be a good way... it would be separate of the tractor hydraulics.
A concern: Is the FM cultivator going to handle full fertilizer boxes hung on it??? Especially when you get sick of filling every 3 acres and build extentions?
Why not put the fertilizer down with a spreader in one pass (quick) and then come back and cultivate it in?