This week's key to the cosmos, and the meaning of life: thin-ness.
We're not talking weight loss; rather the marvel that so much of what is vital to life occurs in such skinny slices of the biosphere.
We marvel at the boundlessness of outer space, yet it is only in the lowest sliver of atmosphere that terrestrial life can exist.
Ocean depths fascinate us, but it is in the coastal marshes and shallows, and muds of the continental shelves, that the huge bulk of aquatic life thrives.
Nothing exemplifies life's propensity for little layers more than topsoil, the merest gossamer skin on our thick globe, but the only part that grows green plants.
Such thoughts of thin miracles occur in a Worcester County woodland, where last week soil scientists George Demas and Dick Hall showed off Maryland's new "State Soil."
They brought the tools of their trade: a hand-driven auger-like device, which requires enough muscle that Demas once cracked ribs extracting soil cores with it.
They also brought their bible, as Demas calls it: "Keys to Soil Taxonomy, 5th Edition," plus a book of color chips of every hue in which soil occurs, and a plastic spray bottle.
Hall twists, slicing the auger's hollow head through the forest roots and down about a foot, pulling up a plug of fine-textured, brownish yellow soil. Demas scrunches a fist-full and crumbles and sifts it through his fingers, like savoring fine wine.
"Some of the best we've got," he says.
Another twist, a deeper core, this one more moist, and slightly heavier and darker; and another, this core turning a distinct reddish brown.
This, the scientists explain, is classic Sassafras, a soil type that virtually defines "prime" or "Class 1" agricultural land across much of Maryland.
It is one of some 1,500 distinct soils identified in the United States, one of 34 types that occur in Worcester County alone.
But this year, to celebrate the 100th anniversary of mapping the nation's soils, Maryland will put Sassafras in a class of its own, declaring it the official state soil.
It did not happen without spirited debate within MAPSS, the Mid-Atlantic Association of Professional Soil Scientists, recalls Demas.
Hagerstown, an excellent Piedmont soil named for the area where it was first identified, had strong support.
Others championed Othello, a "hydric" soil that underlies wetlands. Othello is not prime farm soil. But wetlands have become such an issue that a hydric soil ought to be given recognition, supporters felt.
Perversely perhaps, Collington soils were also put forth for the honor. Collington soils, which occur in Central Maryland, can leach enough acid to destroy concrete bridges and foundations that are placed in them without protection.
Recognizing Collington would be educational, emphasizing the importance of knowing what soils are where, its backers said.
But Sassafras swept the field, recalled Demas, who maps soils for the federal Natural Resources Conservation Service out of Snow Hill in Worcester County.
It occurs in 18 of Maryland's counties, to Hagerstown soil's four counties. And it was one of the first soils ever mapped in Maryland, beginning with the original national soil survey in 1899, on a farm in Cecil County by the Sassafras river, namesake of the soil type.
"It is one of our top crop producers -- easy to plow holds moisture without being soggy There are almost no limitations on it," Demas says.
Ironically, he adds, Sassafras is as beloved by developers as by farmers, with no engineering limitations and easily able to handle septic systems.
Demas spritzes the Sassafras cores taken from the forest floor with the spray bottle. "It brings out the color." Then he shows how samples are compared with color chips. This allows scientists to standardize soil comparisons.
Soil mapping has become sophisticated since it began a century ago. An early map of Worcester County shows nine soil types. The 1996 map shows 34 types.
And the early emphasis on identifying good places to farm has evolved. By mid-century, erodability was an important characteristic to know, as soil conservation efforts grew.
Recently, knowing where wetland soils lie has been critical, both for preventing wetlands losses from drainage and development, and in knowing where to get the most bang for the buck in restoration efforts.
Both Delaware and Pennsylvania (but not Maryland) now require soil scientists to site septic tanks and their drain fields.
Soils have been mapped and remapped for a century now, and you might think scientists would be finished. But Demas recently opened a vast new territory.
For his Ph.D. research, he proved for the first time anywhere that the shallow bottoms of Maryland's coastal bays, were not just undifferentiated "sediment," but contain scientifically distinct soil types.
The implications are huge for restoring and protecting submerged aquatic grasses in places like the Chesapeake. Like crops on land, the grasses do better, water quality being equal, on some soils than others.
Someday, we may proclaim a state underwater soil, and the debates will rage among Patuxent, Choptank and Sinepuxent. Maybe there will even be a Sassafras.
Pub Date: 9/10/99