Underneath It All

The world generally thinks of Martha's Vineyard as a tourist destination. And, indeed, that land use has been growing steadily on the island at the expense of both fishing and farming. Farming is making a comeback on the island and perhaps has been since the 1970s. The recent nationwide interest in sustainability and locally-sourced food is manifested on Martha's Vineyard in forms like the Island Grown Initiative, the success of The Grey Barn and Farm, and a list of 43 farms collected by the Martha's Vineyard Times that reveals an impressive variety.

The figurative and literal basis for farming is the soil. One of the standard references for learning more about the substrate is a soil survey, which in this country are generally issued county by county. Martha's Vineyard forms the bulk of the County of Dukes County. (The strange name is an artifact of an eight-year interlude between 1683 and 1691 during which the island was a county of the colony of New York. The aristocratic name jibes with Queens, Kings (aka Brooklyn), and Dutchess counties, which all remain part of the Empire State. So, while Cape Cod is the County of Barnstable, Martha's Vineyard, the Elizabeth Islands, and Noman's Land were incorporated as the county of another colony's county.)

The Dukes County Soil Survey was last completed in 1986, but is also available as an online (web soil) survey, as are 95 percent of the U.S. Department of Agriculture surveys. The surveys are attributed to staff of the Soil Conservation Service, in this case Peter Fletcher and Rino Roffinoli with fieldwork by them and other staff, but the history and geology sections were contributed by William Wilcox, a local soil conservationist who worked for the Martha's Vineyard Commission, and Rudolph Chlanda, a geologist with the Soil Conservation Service.

It is sort of amazing what you learn in a soil survey; some of the information is only tangentially to do with soils. For example, Wilcox, in his thumbnail history of the island, writes that after 1866, when the new petroleum industry began eroding the whale oil business, the Oak Bluffs Land and Wharf Company began subdividing the land on the island to sell off for summer residences, a trend that has continued ever since.

Because population affects land use, Wilcox cites the U.S. Census data. In 1950 there were only 5,633 people on the island. By 1980 there were 8,942. There was a corresponding increase in the amount of acreage with an urban use — 1,705 to 5,855 — and a decline — 5,131 to 2,442 — in the amount used for agriculture. An interesting fact: Wilcox writes that at no time (presumably during the period of European settlement) was farming a more important part of the economy than fishing. This contradicts an assertion by Nora Ellen Groce in Everyone Here Spoke Sign Language, a history of the deaf community on Martha's Vineyard. Groce claimed that the settlers farmed out the soil and then took to the sea. The decline of farming, Wilcox said, began after World War II, just as it did in most places in the United States.

Wilcox and Chlanda called the terminal moraine that makes up the upland northwestern part of the island a "variable matrix of sand, silt, and clay." The northeastern part of the island is this moraine covered by outwash that eroded off of the northwestern part. (Perhaps the Cape Cod lobe of the icesheet retreated before the Buzzards Bay lobe?) The interior of the island and the southern shores consist of outwash from the moraines, which Chlanda describes as deposited by "tremendous braided streams laden with sand and gravel."

Morning Glory Farm on the outwash plain in Edgartown.The soils that formed from on top of these mineral substrates are most often described as sandy loams. A loam is a substrate that is on average 40 percent sand, 40 percent silt, and 20 percent clay. It is regarded as the basis for good arable land. The USDA has a formal definition of "prime farmland." It has the "soil quality, growing season, and moisture supply needed to economically produce a sustained high yield of crops when it is treated and managed using acceptable farming methods." According to the county soil survey, 11,200 acres or almost 17 percent of the Vineyard meets these requirements. In 1986 about 600 acres of this land was being used to grow crops, mostly silage, alfafa hay, vegetables for roadside stands, and grapes.