SABATTUS – Use the term “car pool” in the Sabattus area and you might start people drooling. Rather than a group of people riding together to go to work, or taking children to school, dozens of Sabattus-area residents car-pool to Willow Pond Farm, where they pick up their weekly allotment of fresh vegetables, fruits and herbs.

Worked by Charles and Jill Agnew, the farm participates in community-supported agriculture, or CSA, which is a working example of the theory that “one hand washes another.”

All those folks sharing a ride to the farm purchase shares in the harvest upfront, before spring planting, allowing the Agnews to have ready cash for planting expenses. As the crops grow and ripen throughout the summer, the shareholders show up weekly to receive their apportionment of the bounty.

According to the Maine Department of Agriculture, 30,000 to 50,000 consumers nationwide rely on CSA arrangements. Although firm figures are not available for Maine, it is estimated that several thousand people have formal or informal CSA agreements with Maine farms.

The share agreements between farms and customers vary. Some customers buy a share and get a bag of produce each week. Others use their share as a credit system, either buying directly at the farm or through the farmer’s display at local farmers markets.

CSA is sometimes called pre-order, share farming, or farming by subscription, and it is becoming an increasingly popular way for farmers and their neighbors to become partners for mutual benefit.

Although the concept has been around for more than 30 years, it is just catching on in Maine.

The Maine Department of Agriculture officially lists 24 CSA farms, half of them certified organic. Many offer unique products and arrangements.

Denise and Craig Chick in Monmouth offer a “Select-A-Tree” program, where customers can choose an apple tree in the Chicks’ orchard, leave a deposit and come back in the fall and harvest the fruit.

Daniel and Carol Doyle provide poultry products, including smoked turkey breast, duck and fresh chicken. Other farms offer flowers, medicinal or culinary herbs, eggs, broiler chickens, seedlings or maple syrup.

There are several kinds of CSA arrangements, but most involve payment in advance.

This enables the farmer to pay for the cost of planting without borrowing and to dedicate time and energy to farming.

Shareholders are assured the highest-quality produce and other foods at fair market prices, while the farmer is guaranteed a reliable market.

Beth Ranggan and Gregory Wheaton of Wassookeag Farm in Dexter are participating in CSA for the first time this year. The close relationship that CSA fosters between the farmer and the consumer is something they look forward to. “You get to know your customers,” said Ranggan. “You can prepare for their needs and grow appropriately for them.”

Tom Roberts and Lois Labbe of Pittsfield offer $100 shares, which translate into credit either at their Snakeroot Farm or at Tom’s display when he sells at farmers markets in Orono, Unity, Fairfield and Pittsfield.

Roberts said that CSA shares amount to only a fraction of his entire business but it is one aspect he likes. “The biggest advantage is cash upfront. For farmers, in the springtime, it is all outgo and no income.” Last year, Roberts had nine CSA customers.

“Another advantage,” he said, “is that CSA binds the customer to us in the buying markets.” At farmers markets, Roberts said, his CSA customers come to him first, rather than patronizing the other sellers.

He admitted that “there is a certain amount of trust involved between the farmer and the customer. You need some kind of history.”

In Maine, depending on which farm a consumer has an agreement with, a CSA farm can begin delivering produce in January, with winter apples, potatoes, dry beans, and squash.

Farms using greenhouses can begin offering tender greens and herbs as early as April, with most CSA farms beginning their harvest in June, July and August. Storage facilities can provide additional crops right through December.

Roberts said he would be offering seedlings, lettuce, carrots, spinach and parsley at the first round of farmers markets, the week of May 7. “By mid-May we will have rhubarb and asparagus.”

A complete list of Maine’s CSA farms may be obtained by calling the Maine Department of Agriculture at 287-3491, or contact the department’s Web site, www.getrealmaine.com.