If you are REAL lucky (and a bit of a shadetree electrician) you may be able to reconnect those wires and insulate same well enuff to make do.
If you look under your tractor , there is a static plate - (part of the clutch assy) that bolts up to the frame and holds one part of the clutch assy static (the part carrying the wire harness). That part apparently came loose and caused your wiring problem.
That assy will have to be re-attached to the tractor. You will have to have the hardware to do it. The other thing to chk while under there is that the PTO pulley that normally drives the mower blades turns freely on it's own bearing with all power off. If it drags or turns hard, then the PTO assy must be repaired or replaced ($$$$Ouch!) Good Luck.