I would go local.

Like LS said, I would then hope that the extra $ earned by the farmer could be put to instituting better practices.

I also believe in the economies of scale and think that although having little organic farms dotting the countryside is lovely, it's not always environmentally "best practice".
are we not better off having one farm of 100 acres, with 1 house, 1 road 1 lot of farm machinery etc and leaving the rest of the country side undeveloped than having 20 farms of 10 acres, miles of road, extra houses, cars, building a shop, putting in a petrol station etc.
The more I think about it the more I believe that the future health of our land, infrastructure and economy, especially being such a vast country, is dependant on us becoming more high density living minded.
I think it is a sounder model, keep people and nature separated. That way you can much more effectively maintain both.
Sorry, gone totally OT, and a bit ranty