The food is probably more nutritious because it’s not as old, it hasn’t been transported thousands of miles (a variation of the latter point), and the soil richness of the small farm may be superior to that of big industrial farms that have depleted the minerals in their farmland through high crop yields over the generations (there are exceptions of course, and few farms are perfect—wash all the food!).

For the same reason why you might consider getting a mortgage at the bank down the street, using the local car garage, or quaffing your morning joe at the Hippie Gal Café rather than the mall (sorry, Starbucks)—supporting local food producers makes for a stronger community.