AMES, Iowa — From the old paper soil maps to the new, high-tech, interactive environment of Soilscape.org, Iowa State University scientists have led efforts to characterize a largely hidden landscape — the ground under our feet, farms, homes and businesses.
Soilscape
Advanced soil mapping techniques leverage digital, geospatial tools that make soils information more immediate, accessible and communicative, according to Professor Bradley Miller, agronomy, manager of Iowa State’s Geographic Laboratory for Soil Informatics.
“We are improving capabilities all the time,” Miller said. He is one of the creators of Soilscape. The new public resource integrates data from the long-time soil survey data with advanced landscape analytics to enhance public access to comprehensive soil information.
“Soilscape offers user-friendly tools and visualization that empower researchers, land managers and the public to explore and understand soil and environmental data like never before,” he said. “Using the website’s interactive maps, you can easily turn on or off layers of information relevant to your interests.”
At this point, the resource is most well developed for Iowa, but the team, which includes Michigan State University partners, plans to continue updating the platform to add details and expand the coverage areas. They are also working on a set of tutorials to make it easy to find soil descriptions for a particular location.
Soils change
Tools like Soilscape have led to identification of new soils in Iowa. In 1971, 270 soils had been identified in Iowa. Now, more than 500 soils have been described in the state, according to soil scientist Lee Burras, Morrill Professor of Agronomy at Iowa State.
“Soils are not static,” Burras said. “There is a misperception that ‘once a Clarion loam, always a Clarion loam.’ We have the same amount of land, so what changed? We’ve learned more as we have refined soil survey interpretations, largely through these new digital soil mapping techniques.”
For example, there is a need to update information about soil organic matter, which is essential to predict nutrient needs for crops, Miller emphasized. “What we have is a reasonable starting point, but agronomic models can’t be reliable until that information is improved.”
Soil matters
A complex mix of earth, soils are formed by the “parent material” in a specific location interacting with climate, living organisms and topographical relief, over very long – and sometimes surprisingly short – time scales. Iowa’s soils, generally rich from eons of decaying prairie plants and melting glaciers, have long been recognized as a unique and valuable resource that undergirds agriculture, the state’s most important industry.
The National Cooperative Soil Survey was founded in 1896, and Iowa’s first soil map was created for Dubuque County in 1902. In the 1950s, leadership for the soil survey was assigned to the USDA Soil Conservation Service (SCS), now the Natural Resources Conservation Service. SCS staff did much of the field work to sample soils, sending thousands of soil core samples to laboratories at Iowa State and elsewhere to be studied and characterized. The results were published in large volumes of soil maps that located soils in closely related “series” reflecting a spectrum of characteristics such as depth and climate.
Much of the work was supported by USDA, in part through the collaborative NCERA3: Soil and Landscape Assessment, Function and Interpretation — the third regional USDA multi-state project in the country, which continues today. Burras and Miller serve on the committee, building on the legacy of Iowa State soil scientists Gerald Miller and Tom Fenton, who helped found the group.
The soil mapping conventions the committee established decades ago provide a wealth of information about a piece of land, including its drainage potential, slope and soil structure. Such considerations are important, whether one is considering a building project, constructing a pond or installing a conservation practice.
The soil maps also include corn suitability ratings (or CSR values) used to help compute a land’s value for purposes like tax assessments based on soil types and their potential productivity. In 2013, the CSR values were updated. Burras led development of the revised CSR2 system, and he continues efforts to refine methods to describe the factors that impact soil structure.
“Understanding why and how our soils are changing over time is important information that affects agriculture and the quality of our lives in many ways,” Burras said.
“The goal of Iowa State’s leadership in soils identification and education has always been to help people better understand and find value in soils so this vital, high-quality resource can be appropriately managed and sustained for the future,” he said.
Contacts
Lee Burras, Department of Agronomy, 515-294-0559, lburras@iastate.edu
Bradley Miller, Department of Agronomy, 515-294-8077, millerba@iastate.edu
