How did the Cunninghams pay for things in their impoverished state in To Kill a Mockingbird?

We don't know how all of the Cunninghams paid for their
goods and services, but we do know how Walter Cunningham Sr. paid for Atticus' legal
work. Atticus served as Mr. Cunningham's attorney for his problems with "entailment"
issues, and during a conversation in the Finch's living room, Scout overheard Cunningham
tell her father that "I don't know when I'll ever be able to pay you." Atticus told him
to "Let that be the least of your worries." When Scout asked about it, Atticus told her
that he wouldn't get any money, but that he would be paid "before the year's out." Sure
enough, Atticus was paid--in goods. First he received a bag of hickory nuts; then came a
"crate of smilax and holly." After receiving "a crokersack full of turnip greens" the
next spring, Atticus considered the debt paid in full.