UI's soil monolith king
by Diane Noel
Maynard Fosberg has almost certainly collected more
soil monoliths than anyone else on Earth. He puts the number at about
350. Until he turned 50, the now retired UI soil scientist excavated the 5-foot
columns of soil from pits he dug by hand—pits big enough to hold two men
6-feet deep. In 1970, he hung up his shovel for a backhoe.
Fosberg, fit at 86, still collects monoliths
and teaches his technique to others.
Photo by mark LaMoreuax.
Today, 86 and vigorous, he still collects monoliths. His quarry
this spring is the soil under his horse pasture (he still rides) on the floodplain
of Paradise Creek in Moscow. “Really, we don’t have a monolith that
tells this kind of story in our collection,” he says.
The collection is the Maynard A. Fosberg
Monolith Collection at the College of Agricultural and Life Sciences. Its 232
monoliths, most collected by Fosberg and his students, make it one of the largest
in the world. The monoliths encompass the huge variation in the state’s
soils—from gravels and sands left by melting glaciers north of Coeur d’Alene
to windblown silts in the Snake River Plain—and a good deal of the variation
in soils nationwide.
Mouse over the individual monolith to reveal legend.
Reading layers like historical
Each monolith consists of a series of natural
soil layers, and Fosberg reads each like a historical tablet. “It’s
a record of the effects of climate, the effects of vegetation, the effects of
parent material, the effects of time,” he says. “When you see a monolith
for the first time, you can tell the plant community it’s related to, something
about its climate. If you understand what you’re looking at, you can sort
of reconstruct the history of that soil.”
The history of the soil under his horse pasture
starts at the bottom with sands carried in Paradise Creek water from the very
old granite on nearby Moscow Mountain. Next comes a thick layer of loess—silt
blown in from Washington on prevailing winds. An ash layer 10 inches thick marks
the date 7,700 years ago when Mount Mazama erupted in Oregon. On top of the ash
lies a foot of silt eroded from the highly productive—and highly erodible—wheat
A monolith collected less than a mile away tells an entirely
different story. Its 6 feet of mottled reds, tans, and whites date back 10 million
years. “It’s a typical tropical soil preserved under this landscape,”
To collect a monolith, Fosberg cuts a vertical slice of soil
8 inches wide and 2 to 3 inches deep extending from the soil surface down 5 feet
or more into the subsoil, ties the intact soil section on a board, and lifts it
out of the pit. Back at the lab, he works on the soil profile to reveal its structure
and color, mounts it permanently on a plywood board, and stabilizes it with resins.
Bringing the field to the student
The monoliths are “really valuable
teaching resources,” says UI soil scientist Paul McDaniel. “It’s
like bringing the field in to the student.” Lining the walls of the first
floor hallway in the Agricultural Science Building, the well-labeled collection
is open to the public during business hours.
Fosberg specialized in soil classification, land use planning,
and soil-plant relationships before he retired in 1989. Since then he has coordinated
the Idaho state land and soil evaluation program in which more than 500 Idaho
high school students compete each year. An endowment in his name supports that
competition and provides scholarships for UI soils students.
“People are always saying, ‘What the heck are you
doing? You’re retired. You’re working like you always did,’”
Fosberg says. This summer, he intends to plant native Palouse Prairie plant species
on 1.5 acres of his land, plants perfectly suited to the soil.
Contact Fosberg at mfosberg@GoVandals.com,
or McDaniel at email@example.com.
Who cares what kind of soil it is?
A soil scientist’s bible, The National Soils Handbook lists more than 60
land uses—from septic systems to golf course fairways—and gives properties
of a soil that can put limits on each. Some soils are too unstable for road building;
some too wet for septic tank drain fields.
Soils under the UI, it turns out, are far better suited to farming than to building
construction. Silty, they hold water well, but are weak and prone to frost heaving.
Extensive flooding in New Orleans after Hurricane Katrina illustrates potentially
disastrous consequences of building on soils with severe limitations for construction.