I'm new to the Permies website, and just a little bit less new to the whole homesteading/permaculture/food forest world. Please forgive me if this topic has been discussed at length in the past, but after a quick search through the forums I was unable to find a topic that answered my question.
I live in central Arkansas (border of zones 7/ on about 5 acres that has been used solely for horse pasture and has quite a bit of water flow during the wet season. It's sandy to silty loam and seems to have a pretty decent texture. I had my soil tested which showed a pH of anywhere from 4.3 to 5.1 and poor nitrogen content. We actually have a ton of growth where the horses haven't been, mostly sweet gums, buttonbush, pokeweed and a ton of thorny vines in addition to the older hickory and oak. My goal is to condition the soil and raise the pH to a more neutral level in preparation for our permaculture aspirations. Obviously, 5 acres is too much to bring in municipal compost (which I'm not sure I trust due to persistent herbicide/pesticide/fungicide contamination, anyway), but I'm really not fond of the idea of tilling and spreading lime in order to quickly fix the pH. We hope to be able to plant food for ourselves in the spring, if at all possible. So here's my question... Do I have any options beyond lime for significantly changing the pH of this soil in a reasonable amount of time? Can I use green manures to condition this type of soil and bring up the pH before spring planting? Are their other options that I am not aware of for increasing pH beyond adding lime or compost?
substantially changing the pH before Spring might be a tall order. do you know the history of the land and how the pH got so low to begin with? if it's due to previous management, chances are good you can reverse the problem. if it's due to local climate and soil conditions, chances are still good you can improve things. expecting that to happen quickly, though...
wood ash can take the place of lime. you don't have to till it in since it will wash in with the rain. just be judicious in your application.
my first step for improving soil is almost always trying to add organic matter. mulches, hugel/soil banking, deep rooted cover crops, intensively managed grazing. these and others are effective methods of getting more goodness in your dirt. that organic matter will also help microörganisms hang onto more nitrogen and provide more cation exchange capacity. chances are pretty good that your low nitrogen is directly related to the low pH, and the organic matter will help both.
that there are plenty of plants growing well already is certainly a good sign. honestly, I might not worry too much about the acid until something you plant shows signs of pH distress.