Rules on page 123 say:
"to fire a bombardment an artillery team must either:
spend the whole turn stationary, or
Unlimber in the movement step provided the gun team remains where it started the turn aside from rotating."
The rule for digging in on page 51:
" Rather than move, a platoon can use their movement step to attempt to dig in.....
Regardless of whether they succeed or not, every team that attempted to dig in is treated as having moved when determining its ROF if it shoots (see page 91), but not for any other purpose."
So can you dig in and fire bombardments on the same turn? What about missions (Meeting Engagements) that have you count as moving and not being able to fire bombardments in the first players turn?