My favorite radio station, WWOZ in New Orleans, specializes in local roots/traditional music, which is NOT the same as "folk music" in the generally accepted sense, and which is also not necessarily acoustic.

HOWEVER: There are a few individual shows that might be appropriate for your material:

Saturday 10-11:30 am: Sean O'Meara, "Music in the Glen" (Irish/Celtic)

Sunday 10-11:30 am: Hazel the Delta Rambler, Old Time Country & Bluegrass

Sunday 2:30-4 pm: Your Cousin Dimitri, Acoustic Blues

Each of these specialized program has its own seriously devoted "niche" audience, and since the station is webcast, there are listeners all over the world. To contact any of these DJs, go to this schedule page on the station's website, find the desired program on the schedule gird, and just click on the show-host's name to send an email.