I have an out of state farming investment in California. The investment had no profits this year, just depreciation. I filed a federal k1, do I need to complete a CA?

Yes, you need to file with California.  For California to know about the loss, so you can carry the loss forward, you need to file a return with them

The general rule is that is if you do not file then you loose the loss and cannot take a deduction for it when you have income.

@andrew-uthoff