Imagine this: You’re a potato farmer, but you start to notice something odd about your sandy soil. When you spray water on the mounds piled around each plant, the droplets roll off the soil like water off a duck’s back. It’s as if someone had sprayed a water repellent on your field. You dig into the top of one of the mounds and see that it’s bone dry. You scoop up a handful and dust trickles through your fingers. You realize that your plants aren’t getting the water they need to survive.
Actually, this is happening around Hermiston in northeastern Oregon, where agriculture relies heavily on irrigation. The cause and a solution haven’t been found, but soil scientists at Oregon State University are looking into it. As they well know, in Hermiston and elsewhere, soils can be a mystery.
“Leonardo da Vinci said we know more about the movement of the celestial bodies than we do about the soil underfoot,” said John Baham, a soils professor at OSU. “We know about the planets, atmosphere, oceans, and forests, but when you get down to the stuff below our feet, it’s a mysterious world.”
OSU’s own soil detectives are trying to demystify this subterranean universe. In labs, in the classroom, and in the field, they’re looking at soil and asking, “What’s going on down there?”
James Cassidy is one of them. On the first day of his class this fall, he strolled in, left hand in his pocket, wearing black sneakers, a plaid sport coat, and a rainbow-striped shirt buttoned up to his Adam’s apple. He had pens in his lapel pocket and two earrings in his left ear.
Cassidy used to play bass in platinum-record Information Society, a band that had millions of teenagers dancing to “What’s on Your Mind (Pure Energy)” in the 1980s. These days, soil is what’s on Cassidy’s mind, a subject he has spent considerable energy studying.
“I hope it doesn’t come as a shock to you, but I’m not a soil expert,” he said right off the bat, gesturing exaggeratedly with his right hand, like lawyers do when questioning a witness.
“Soil is the fundamental natural resource that makes everything possible,” said Cassidy, the current president of the Oregon Society of Soil Scientists. “Millions of people have profited from soil and died and been buried in it and never thought what it was.”
Part of Cassidy’s job is to get students excited about what’s under their feet. He does it with a bit of theatrics honed from years as a performer. He likes to shock, telling students to develop a taste for grub worms and corpses because they’ll be the food of the future. Amid such antics, he makes sure students leave his class with a solid understanding of the fundamentals of soil.
“Soil is truth,” he told them. “It’s indisputable that we depend on soil for our survival. We’re not going to live on Mars. If I’m wrong about that, I’ll give you 10 extra credit points.”
Soil, he said, is rotting rocks. It’s the space, often about 6 feet deep, between the Earth’s rocky bones and its weathered skin. It is the meeting place where air, water, minerals, and organic matter come together. It’s a habitat, alive with bacteria, fungi, nematodes, protozoa, earthworms, and voles. It helps plants grow, recycles nutrients, purifies water, provides habitat for soil organisms, serves as an engineering medium, and even archives ancient information (the oldest recipes for beer were written on clay tablets, Cassidy said.)
To really understand soil, you’ve got to become a kid again. You’ve got to play in it, get your jeans dirty, roll mud snakes in your palms, smell it, even taste it. That’s where Will Austin comes in. He’s the adviser for OSU’s soil judging team. Yup, soil judging.
Austin spends weekends and weeknights with an eclectic group of soil judging students who wear shirts that say “SOIL” and “You dig?” One year, they tie-dyed shirts with the reddish-brown stain of Oregon’s unofficial state soil, Jory.
Soil judging works like this: You stand chin-deep in a pit the size of a car and face a wall of soil. The clock is ticking. You’ve got less than an hour to figure out how many different layers of soil there are and where those layers begin. And for each of those layers, you must determine the precise color, the exact texture (is it sandy clay, loamy sand, clay loam, silt loam?), and the structure (blocky, columnar?). And that’s just the start. Meanwhile, you’re staring at this wall thinking this just looks like a bunch of dirt.
On a Sunday morning in October, Austin and the team gave it a whirl in their first practice of the school year. A regional competition was only three weeks away that would pit OSU against the University of Idaho and Utah State University.
Tools in hand, students hopped into the pit. “OK, let’s see what kind of damage we can do,” said Austin, a former mountain climber and a laid-back, Jimmy Buffett kind of guy who looks most at home in a Hawaiian shirt and riding his Triumph. He handed out scorecards.
This can be intimidating for the uninitiated. Austin recalled one student breaking into tears upon being faced with a wall of soil and a checklist of demands to identify horizons, boundaries, textures, colors, and something called redox concentrations. Students must measure hydraulic conductivity, rooting depth, water retention, slope, surface runoff, and more. Basically, these smarty pants are trying to answer questions like: Can you grow crops in it? Can you build a house on it? Can you bury a septic tank in it?—questions they would need to answer someday as crop consultants, wetland specialists, or hydrologists.
The team got to work, squirting water on the wall of the pit to help define the layers. They jabbed at the pit wall with knives. They rolled mud balls in their hands. They held dirt clods next to a book of color samples as if trying to match a piece of fabric with a color swatch at The Home Depot.
Austin asked his team to look at what’s above ground, too, for clues to what hides below the surface. He surmised that the area was once the bottom of a lake formed by the Missoula Floods, and the floor of the pit probably dated back 40,000 years. That’s when it hits you. You’re touching soil walked upon by woolly mammoths.
“This is a page out of the history of the Earth. If you know how to read the page, it’s fascinating history. Plants change, but soil is always here,” Austin said.
OSU soil scientist Jay Noller has read that book. He postulates soil types by observing landscapes—both on foot and with the help of technology. He and his research team are using satellite images and flyover photos to map the soils in Malheur County in the first soil survey of the area. The results will help farmers, ranchers, and policymakers decide how best to use the land.
Noller also teaches students to classify soils, which are ranked in a system similar to plants, with orders at the top of the hierarchy and series at the bottom. There are 12 orders of soil in the United States, everything from tundra to desert. Oregon is known to have at least 10 of those orders, and Noller has found the other two. He located a parking lot-sized piece of Gelisols containing permafrost on the flank of Crater Lake. And he found Oxisols, weathered soils from the tropics, in the John Day Fossil Beds National Monument. As for soil series, there are more than 3,200 of them in Oregon, Noller said.
You can find 27 of Oregon’s soil series displayed in a string of monoliths hanging on the wall of a campus lab. It looks as if someone had sliced the state from east to west with a 6-foot knife. The monoliths carry names that you might find in a phonebook, names like Frohman, Hankins, Morrow, Dupee, Steiwer. On the Ochoco monolith, you can see how the salt drained through the soil and accumulated in the bottom layer. The top half of the Blacklock, found on Oregon’s coast, is gray and sandy then abruptly turns earthy brown. The silty Nehalem, found in floodplains, has roots poking out and dead grass matted at the surface.
Noller thinks about these soil series when he’s driving. As the landscape zips by, he can’t help but wonder what’s below the surface. At a forested terrace above the beach, it’s not the trees he sees but the Blacklock below. Back home in his art studio, Noller captures those soil profiles on canvas. To see some of his paintings, go to his blog The Art & Science of Soilscape Painting.
While Noller examines soil on a landscape scale, Dave Myrold examines it on a microscopic scale, working in a world in which a human hair would be the size of a school gymnasium. A soil microbiologist, he studies bacterial genes in soil.
One billion bacteria can be found in a teaspoon of soil, he said. Those bacteria consist of tens of thousands of different species. With new technology, researchers like Myrold are getting a better picture of soil diversity, quickly breaking open bacterial cells and isolating their DNA.
“Just as criminal investigators get DNA from semen, we’re extracting it from the soil,” Myrold said. With equipment that can do hundreds of thousands of genes simultaneously, you could conceivably sequence everything that’s in one teaspoon of soil. “That’s way-cool technology, but what does it mean?” Myrold said. “Just because you have 10,000 species of bacteria, why does it matter?”
For many bacteria, it may not matter. But some species have specific, valuable functions, he said. The bacteria might be able to degrade pollutants in the air, make antibiotics, or generate electricity.
Whatever their potential uses, the bacteria are just one of the thousands of critters who’ve set up housekeeping in the soil, making it all the more complex and mysterious. “What is above ground is a sideshow compared to what is going on below,” Cassidy told his class. “Yet, people are blind to soil. We are so immersed that we don’t get it, like a fish in a tank that doesn’t know it’s in water.”