Petroleum footprint for local farmers markets

I heard Paul mention that local farmers markets producers and patrons use more, or at least as much, petroleum in getting their food back and forth to the market as does the conventional market systems. I have no particular disagreement with this claim and have certainly seen studies that support that view, but I would be interested if folks have any suggestions or resources to look into the question a little further. The conventional mechanisms, I assume, would have fairly consistent parameters of petroleum use associated with them, but the local parameters seem to be more likely to lend themselves to some floating variables. For instance how far the local producers are from the market and how far the consumers travel to the market are significant inputs to the equation. My experience with most farmers markets in this area is that the produce is almost not grown locally at all. I am working fairly diligently on trying to get local, and in my case large backyard producers, to become the predominant contributors to the market. Further if some ride sharing capacities, or other cooperative means used by neighbors to distribute the food in ways that minimize petroleum miles then it seems likely we could change the outcomes of this equation significantly. Thanks

Interesting question.... Let's start by doing some quick and dirty calculations... Most of the industrialized-produce in my grocery stores come from the Central Valley of California, so call it 800 miles away. Big trucks get about 7 MPG, and carry about 40,000 pounds of vegetables. That works out to 1.9 teaspoons of fuel per pound of vegetables: Less than a penny per pound. If I take 250 pounds of vegetables 10 miles to market in a truck that gets 15 MPG, and have to pay to drive the empty truck home that works out to 5 teaspoons of fuel per pound of vegetables. So on a pound by pound basis it takes me twice as much fuel to get a pound of vegetables to market. That's a rough estimate. Some days I take 1000 pounds of food to market. On those days I'd only use half the fuel per pound that industrialized agriculture uses.

Many people stop my my fields to pick up vegetables on their way home from work. That doesn't cost any extra fuel.

My market is local only and producer only, so if we catch anyone bringing in produce that they didn't grow, or that is from more than 50 miles away they get thrown to the wolves.