Web Extra

A Deeper GPS of Soil

New App Lets Students See the Underground Landscape

By Emma Hopkins - Published November 6, 2015

An app developed by Purdue University faculty and students takes GPS mapping of soils to a deeper level than the satellite view of a landscape—deeper, in fact, than the Earth's surface.

The soil map application of Integrating Spatial Educational Experiences, known as Isee, allows students studying soil science or geology to see the landscape using a global positioning system much like the everyday GPS used in cars for driving directions. But in addition to showing roads, these maps show the composition of the soil as much as 6 feet below where the app-user is standing.

Darrell Schulze , a Purdue professor of agronomy, is the lead professor in the Isee project, now being implemented in six other states in various soil-related classes.

Doctoral student Mercy Ngunjiri with an iPad showing the Isee soil map app during a field trip with a Purdue University soils class.Doctoral student Mercy Ngunjiri with an iPad showing the Isee soil map app during a field trip with a Purdue University soils class. (Photo by Tom Campbell)

"It's not just about the app," Schulze says. "It's about the concept of teaching with maps, and the app is the means for doing that. Students connect the concepts in the classrooms to what they see on the maps, and when they are in the field they connect the maps to the actual landscape features and soils that they see."

The Isee project, funded by a U.S. Department of Agriculture Higher Education Challenge grant, combines about 100 years of soil surveying—that's about 4 million survey test holes bored into the ground in Indiana alone—condensed into a terabyte of data. Alberto Martinez, a doctoral student studying agronomy, uses the app for one of Schulze's courses.

"The app is extremely helpful because most people see soils as sort of a random, chaotic feature of the landscape, and what Isee does is help you understand that these soils are here for a reason," Martinez says. "The process is ultimately based on factors like the soil parent materials that the maps show. So rather than being chaotic, soils start to take on a certain order and structure."

"Parent materials"—the sediment, mineral or organic matter of which soils are composed—is only one of the features the app shows. It also can show the elevation, topography, soil properties, drainage, bedrock and other components.

Soil scientists wanting to see a landscape in as much detail as the Isee app provides would need about 10 paper maps in front of them. With the app available, all they need is an iPad.

"There is no better ground truth map of the Earth's surface than the soil survey data incorporated into the maps," Schulze says.

Mercy Ngunjiri , a second-year doctoral student and teaching assistant for one of the soil classes that uses the app, says the technology brings excitement to teaching.

"When we go out into the field and we do the iPad exercises, the students are actively involved," she says. "Some students even have the app on their personal iPads in addition to the ones provided by the department."

In months to come, Schulze says updates to the app will include descriptive text and other user-friendly features.

The app can be found online by searching "Isee soils" in the Apple App Store or at the website http://isee.network.