Soil That's Suitable for Framing

David Verdone, left, and Eddie Earles with soil monoliths made at the National Arboretum. (By John Kelly -- The Washington Post)

Yesterday at the National Arboretum -- under a warm sun and a blue sky -- several dozen people stood around looking at a hole in the ground.

It was a very nice hole: neatly rectangular, about six feet wide, 12 feet long and five feet deep. A lectern and microphones had been set up so people could talk about the hole. Wooden stakes strung with orange ribbon ringed the perimeter and also fenced off the hole's former contents: a huge, ruddy pile of -- dare I say it? -- dirt.

Eddie Earles and Jim Brewer walked down a set of loamy steps that had been cut into the hole and went about the business that had drawn us all to this particular patch of Planet Earth: the creation of a soil monolith.

A soil monolith is a slice of soil about six inches wide, two inches deep and four feet long. Painstakingly extracted from the ground, carefully treated and stabilized, lovingly mounted in a varnished wooden frame, a soil monolith is to soil scientists what the head of a pronghorn antelope is to a big-game hunter: the perfect trophy to display in the office.

Or, in the case of the monolith harvested yesterday, display at the National Museum of Natural History, which in July 2008 will open a $2.5 million, 5,000-square-foot exhibit of soil monoliths from all 50 states, plus the District of Columbia and various U.S. territories and protectorates.

But first, Eddie and Jim, soil scientists with the Department of Agriculture's Natural Resources Conservation Service, had to get the darn thing. They pushed a metal frame over a raised slab of soil carved from one wall of the hole and then screwed a board into the frame. They used a cordless drill to punch holes in the soil behind the slab and then sliced along the dotted lines with a drywall saw, the way a short-order cook would cut meat for a gyro.

Standing above them were their colleagues David Verdone and Susan Davis. David used a little saw to cut through the turf and then Susan slipped a flat-bladed spade into the gap. It was time for the moment of truth.

The idea is to get it out all in one piece, but as Eddie and Jim pulled back on the metal frame and Susan pivoted with the spade, the top 10 inches of soil broke off.

A cry of "Oh!" went up from the crowd, as if a trapeze artist had missed his partner and plummeted to the circus floor.

"It's okay," said Susan. "That was just the plow layer."

The plow layer: the depth to which 19th-century plows reached, back when this area was used for tobacco farming. The offending portion settled back into the frame perfectly and the monolith extraction was considered a success. Later, the soil would be spritzed for several days with a mixture of water and Elmer's glue to render it stable, a teaching tool for the next 50 years.

There are 23,000 types of soil in the United States. About half the states have official soils, the way they have state flowers and state songs. Virginia and Maryland aren't among them, though Del. Anne Healey (D-Prince George's) proposed that Sassafras Sandy Loam get the nod for Maryland during the last session of the General Assembly. The bill didn't get out of committee.

"It was one of those things that couldn't pass the giggle factor," Del. Healey said by phone. "People were concerned about looking silly, even though it really is a serious scientific effort."

The District doesn't have an official soil, either, so what was carved out of the earth yesterday was a "representative soil." Technically, it is a "fine-loamy, siliceous, semiactive, mesic Typic Hapludults," according to a handout. But I prefer to call it by its peppy nickname: Sunnyside Soil. The red, clayey Sunnyside will take its place alongside Maine's Chesuncook, Nebraska's Holdrege and the pride of Texas, Houston Black.

Sunnyside is good for crops, but like a lot of soils, it's good for other things, too: filtering water and providing a foundation for our very lives. Without soil, we'd have nothing to build our strip malls on.

The scientists who study soil wish the rest of us would treat it better. Said Maxine Levin, another scientist with Natural Resources Conservation Service: "They've said that the soil is the skin of the Earth and if you scar it in any way, it never functions quite as well again."

Think about that the next time you have the urge to dig.

Julia Feldmeier helped research this column.