I assume you will have large junction boxes at both ends of the 150', one at the array, and one at house.
At a minimum, you must have PVC stubs from the junction boxes going into the ground to protect the cable (rigid conduit better).
You will probably run 10, 8, or 6 AWG cable depending on how many amps your arrays will be delivering.
You can also breakup the 12 panels into 2 independent MPPTs since the 6000XP has two.
So maybe run +, –, +, –, Ground
Option A
Direct Burial cables UF-B, URD, some PV cable, others
Typically 24" minimum depth required, depending on local codes
Not cheap, not expandable for future runs, no protection from roots, etc.
Don't forget to run a ground wire (not just + and –). UF-B solves that problem
Option B
Buried PVC Conduit buried with THHN/THWN2 pulled through later
Typically 18" minimum depth required, depending on local codes
Cheapest conduit, schedule 80 is thicker than sch 40
Some expansion for future runs, much easier if you use 1.25" or bigger diameter conduit
Run what you need now (+, –, Ground), spend more later if you expand
Option C
Buried Rigid conduit with THHN/THWN2 pulled through later
Typically 6" minimum depth required, depending on local codes
Extremely expensive these days, but should last forever
Some expansion for future runs, much easier if you use 1.25" or bigger diameter conduit
Run what you need now (+, –, Ground), spend more later if you expand