Farming in partnership with the local community. In community supported agriculture (CSA), consumers pay at the beginning of the growing season and receive a share of the farm's crops as the harvest comes in.
A subscription or membership with a CSA farm typically provides enough vegetables for a family of two to four people. When you have a CSA membership, you get a variety of fresh vegetables, some of which you might never have heard of before. You know exactly where your food comes from. Some CSA farms are certified organic farms and/or practice sustainable agriculture. Some farms will let you pay for part or all of your subscription with farm labor. The farm thus becomes a greengrocer, a health club, a tanning salon, and a social club.
A recent harvest at my local CSA farm included starfruit, sorrel, kale, chard, broccoli, carrots, kohlrabi, dill, mei choi, beet greens, and half a dozen kinds of lettuce. The size and variety of that week's harvest is normal for our farm. If the weather is kind, your harvest will be large; if the weather isn't cooperating, your harvest may be smaller.
What's in it for the farmer? Their customers provide seed money up front, pick up the harvest at the farm (saving the cost of distribution), and provide a hedge against a bad year. Perhaps most importantly, the farmer grows a bumper crop of good PR in the community.