One of a kind: college soils laboratory unites characterization services, geotechnical testing
Soil science is life science. And the geotechnical engineers and soil scientists in the Department of Civil and Environmental Engineering working to invigorate the University of Missouri’s Soil Characterization Laboratory are enthusiastic about the critical nature of the work they are doing and its potential impact within the State of Missouri and beyond.
“Can you think of a single life function that isn’t related to soil?” posed soil genesis Professor R. David Hammer who, along with John Bowders, William A. Davidson Professor, oversees the lab’s efforts.
Humans are inextricably connected to the earth’s outermost layer. In addition to providing a growth medium for plants that are a source of both life-supporting air and nutrition, soil filters harmful substances that might otherwise enter groundwater and the food chain. Microorganisms living the Earth’s “skin” help to decompose organic matter and can actually transform harmful substances into something more benign.
Soil also serves as the support for humankind’s vast infrastructure — buildings, roads, bridges and septic and sewer systems. And, it is treasure trove of minerals and fuels as well as acting as a historical receptacle for artifacts and clues to our past and future.
Brief history of soil science at MU
“Professor Curtis Fletcher Marbut started the soil survey — identifying, classifying and mapping of soils — here in Missouri,” said Hammer referencing the university’s rich history and early involvement in soil science efforts.
Marbut, who left his faculty position in geology at MU in 1910, to work with the U.S. Bureau of Soils, continued to direct this state’s soil survey efforts until his death in 1935.
Hammer said that by the time a Missouri constitutional amendment in 1984 created the parks, soils and water tax — primarily to address soil erosion issues — only about one-third of the state’s soils had been mapped to modern standards. Now completed, about 340 of the nation’s 23,000 soils occur in the state.
A 1985 grant from the Missouri Department of Natural Resources provided seed money for MU’s Soil Characterization Laboratory, then housed in the College of Agriculture. A primary goal at its inception was to accelerate the statewide soil survey.
“The knowledge base increased quickly. Because of the lab, we had the ability to map accurately and provide excellent interpretations,” said Hammer, explaining that the project wedded the individual county surveys.
After working with others in the state to complete Missouri’s soil survey, researchers at the facility contracted work from other states around the country.
“We developed an extraordinary reputation,” said Hammer. “We were the first state to digitize our soil survey, and we linked all of the soil data into the digital soil survey, which was available, free, to the public.”
Funding challenges resulted in the relocation of the soils lab to the College of Engineering in 2002, and Hammer came along. The geotechnical engineering faculty in the Civil Engineering Department expanded the work of the lab to include behavioral soil tests.
The lab has operated continuously through the efforts of a dedicated staff that includes Russell Dresbach, Donna Brandt and Paul Koenig. However, the recent economic downturn and a national trend toward increased funding of biotechnology research over soil sciences caused a decline in soil laboratory operations nationally.
Hammer, who left the university in 2005 to work with the Natural Resources Conservation Service and direct the National Soil Survey Laboratory in Lincoln, Neb., has returned. He and Bowders are laying groundwork for the soil lab’s renaissance, revamped and reinvented with investments from the College of Engineering and increased research funding.
“We are expanding the capabilities from classical soil characterization to advanced geotechnical analyses. Dean Thompson, John Bowders and Sam Kiger [associate dean of research] are big picture, forward-looking engineers who don’t see problems, but see opportunities,” Hammer said.
While the characterization side of the lab, under Hammer’s direction, is gearing to document soil health, its elemental properties and composition, geotechnical testing efforts headed by Bowders will look at soil’s physical and mechanical properties: strength, deformation and permeability.
“My focus is to make sure the lab is self-supporting,” said Bowders. He is confident of its future because, as he noted, “We can do things few other labs can do.”
An ongoing research project is one that examines soil properties in the subduction layers of the Sea of Japan to better understand earthquakes. The Integrated Ocean Drilling Program (IDOP) is international in its scope. The soils lab has been conducting tests in cooperation with Mike Underwood, MU professor of geological sciences, who serves as one of the lead scientists for the project, which ships samples all over the world for testing.
Underwood asked the lab to examine deformation and permeability properties in the samples.
“As sediments go deeper and deeper beneath a continental plate, pressure and temperature increase and the properties and structure of the sediments change,” said Bowders. “In the lab, we are determining the maximum past pressure on the sediments by reloading samples and also measuring the hydraulic conductivity of the soils.
“Lots of earthquakes initiate in subduction zones and an overall goal of the IODP is to better understand processes of earthquakes,” Bowders added.
Another current geotechnical emphasis project is a study of radio frequency propagation in soils, conducted in collaboration with Robert Druce, an MU research professor in electrical and computer engineering.
Tyler McKee, a graduate student working with Bowders on the project, manages the civil engineering side of the research, including supervision of student assistants. He is writing his thesis on a reliability analysis of the models developed to forecast the dielectric properties of the soil.
“We have conducted sensitivity and reliability studies for single- and multi-variable models and are working to find what parameters are the most critical to each individual model,” said McKee of the project.
Bowders said that one-third to one-half of the project is based on lab-generated data. The object of the research is to better forecast radio frequency response of soil to ground-penetrating radar. Predicting frequency response would allow its use in the identification of such things as caverns underneath roads and buildings, sinkholes in limestone and soil movement.
“It could be used to identify leakage through dams and seepage of contaminants from underground storage tanks,” said Bowders.
McKee said his lifelong fascination with the geoenvironmental aspects of things like the Midwest’s levees and dams fits nicely wit the work he is doing. “I’d like to eventually make it my specialty,” he said.
“The soil strength surveys we are doing in the lab will ultimately be online. Marrying that with the soil survey takes it one step further,” McKee said. “It could potentially save money for construction efforts. It would be a big advantage to have access to archived geomorphology and engineering characteristics prior to visiting a prospective site.”
McKee, who said the entire experience has given him a better feel for the state’s geology as well as offering him some great networking opportunities, expects to finish his master’s degree in December. By the first of next year, Bowders plans to turn over management of the geotechnical lab projects to him.
“All of our undergraduate students work on projects in the lab and because of that, we’re able to figure out which students might continue on. We recruit about one-third of them for graduate study. It is a perfect pipeline: they know their way around the lab, are familiar with others working there and also understand what research is about,” Bowders said.
“Tyler is a perfect example. He’s developed people and logistics management skills and he is an experimentalist, critical thinker and good motivator of others,” he added.
Soil health emphasis
“People have finally realized that healthy soil is necessary for sustainability for any human use including plant productivity and water quality,” said Hammer. “It’s important to have an inventory of the soils and an understanding of the most important functions soils provide.
“We’re the only remaining soil characterization facility among the land grant universities,” he said. “Our multidisciplinary lab resources can support and manage soil and water resources in economically sound and sustainable ways. And we can do these analyses at a very competitive price.”
One ongoing lab project is a USDA-funded soil carbon inventory. A large environmental consulting firm, Applied Ecological Services (AES), located in Broadhead, Wisc., has contracted with the soils lab to help with a Conservation Improvement Grant they were awarded.
“We are analyzing 1,500 soil cores obtained from the project located in eastern Washington’s famous Palouse farmland, which produces wheat, canola and sunflowers,” Hammer said. “Soil carbon is such a complex thing to measure.”
The organic carbon content in soil is the result of decomposition of residual plant and animal materials, as well as synthesis by microorganisms. This organic matter is crucial to all plant processes. The loss of organic matter occurs for a number of reasons, both natural and due to human activity. Variables include the types of crops planted, cultivation practices, drainage, topography and weather conditions.
Hammer said he believes that we have grossly underestimated the release of the soil carbon pool due to agricultural practices, and that we need to work toward the recapture and reintroduction of carbon into soil where it resided for millennia.
The soils lab also is on contract with the National Soil Survey Center (NSSC) of the U.S. Department of Agriculture to help with soil pH and soil particle size analyses for the EPA’s national wetlands inventory. Particle size analysis reveals the relative percentages of sand, silt and clay in the samples.
“We’ve also received two grants from the state Natural Resources Conservation Service (NRCS) for development of a soil health laboratory that will serve Missouri and the nation,” Hammer said.
“Soil health is focused on a stable soil surface with a viable population of soil micro-organisms that allow maximum water infiltration and minimum runoff and soil erosion,” he added. “There’s an incredible diversity of microorganisms and only a small fraction of them have been classified.”
Open for business
The MU College of Engineering’s Soil Characterization Laboratory is unique in the breadth of testing and analyses services it is able to offer. Hammer and Bowders maintain that there is no lab quite like it in the country due to its collaborative nature in soil science and engineering and the fact that it integrates teaching and research into its mission.
“In addition to performing contract and research work for public and private entities, an ongoing activity of the lab will be to compile geotechnical information including descriptions of subsurface soils based on results of subsurface drill logs and cataloging the soil properties measured in the lab,” Bowders said, adding that, as McKee indicated, the goal is to incorporate the information into an online database, similar to or linked with the Center for Applied Research and Environmental Systems (CARES) site (www.soils.missouri.edu).
Bowders said the current site is a great resource for the public, especially engineers, who need subsurface information for planning, design and construction. He predicted the added widespread availability of subsurface information will allow consulting engineers, government agencies, academics and others to augment their usually budget-limited subsurface exploration and testing.
“They can focus their funding on obtaining more detailed or widespread subsurface information ultimately leading to improved project designs for lower costs, higher reliabilities or both”
“The lab is already set up and we are accepting samples from the private sector,” Hammer said. “This kind of testing is traditionally pretty expensive, but we have a competitive edge as students work with us to conduct tests and at the same time, get experience that will help them in their future careers, wherever they go.”