acidifying soil for blueberries - any non-purchased options?
I'm wondering if there are any alternatives to purchased amendments for lowering soil pH for blueberries. Is there any kind of farm/forestry/etc. product/byproduct that could be used? I've heard that pine needles don't really do a whole lot, but would they be effective over the long-term? I know wood ash can be used to sweeten soils. Is there any locally source-able counterpart for acidifying?
What about fertilizers for blueberries? Is there any way for a "self-sufficient" farm/community to fertilize blueberries? I tend toward preferring to substitute labor for purchased inputs when there are options, so I'd just like to know about options.