Wednesday, December 15, 2010

From the Ground Up: Soil comes to life in the Classroom

by: Raylene Nickel

Soil comes to life in the classroom of vocational agriculture teacher Marcus Lewton at South Heart High School, South Heart, North Dakota. His creative teaching tools, contained in a soil-quality tool kit, unveil to students the microscopic citizens of the soil, such as fungi and bacteria. Students also learn the critical role of all microorganisms in soil and plant health.
For high school senior Michael Zarak, whose parents farm and ranch near South Heart, learning about soil builds a foundation for the future.


“It’s important for young people to learn about soil so we will have that knowledge if we do decide to get into farming,” he says.
Zarak’s new view of soil learned from Lewton drew him to educational events where he saw the benefits of cover crops.
“I didn’t know that you could plant all this different stuff after harvesting cash crops,” he says. “I learned that all these different types of cover crops really help out the soil and make the ground more productive.”
Making the connection between healthy soil and robust crops was Lewton’s aim when he conceived the idea of creating soil-health test kits for use in vocational agricultural classrooms. Each kit contains simple tools for vo-ag teachers to use to illustrate characteristics and processes of soil.


Lewton got the idea for the kits while attending a soil-health seminar for vo-ag teachers. The seminar presenter, USDA-ARS soil microbiologist Kristine Nichols, showed participants how to use inexpensive, homemade tools to demonstrate various soil-quality aspects. She also presented instructions showing how to build the tools, how to use them, and how to interpret the results.
Drawing ideas from Nichols and other soil-health sources, Lewton designed a simple soil-health test kit for use in vo-ag classrooms. He then got a grant from the USDA’s Sustainable Agriculture Research and Education program. With help from the high school’s shop classes, Lewton and his students built 100 kits for vo-ag teachers in North Dakota and 60 kits for instructors in Minnesota.
Each kit includes PVC pipe, sponges, nitrate strips, and Styrofoam cups. Also included are instructions telling how to use the tools to demonstrate characteristics and processes of soil.
“Soil health can be a boring subject for high school students,” Lewton says. “But this kit makes it more exciting.”
One test, the Soil Clod Test, demonstrates differences in the aggregate formation of soil that is stable vs. soil that easily falls apart.
Students drop clods of soil into jars of water and note its response to water and gentle shaking. This invites discussion of how soil structure impacts soil functions such as air and water flow, biological activity in soil, and nutrient cycling.
To demonstrate water-infiltration differences among soils and to link these to management practices, Lewton’s students take soil samples from a pasture, a no-till field, and a field in a fallow-crop rotation.
“We put each soil sample in a 5-ounce cup, filling each cup to the same level,” Lewton says. “We then drop equal amounts of water in each cup and watch the water infiltrate the soil. The water in the pasture sample always soaks in faster than the water in the other soil samples.”


Adding an element of competition makes the lesson more interesting and further illustrates differences in water-infiltration capabilities of soil. The game involves predicting which of two soil samples has the best water infiltration. One of the soil samples comes from clay-based pasture hills and the other comes from a heavily tilled garden.
“The students usually predict the garden soil will win. But the clay soil from the pasture always wins,” Lewton says. “The game breaks down stereotypes that kids have about soil and shows the effect tillage can have on water infiltration.”
As vo-ag teachers put Lewton’s soil-health test kits to work in their classrooms, students across North Dakota and Minnesota will learn similar lessons about soil quality.
“These kids are the farmers of the future,” Lewton says. “By teaching them about soil health and soil quality, we’re giving them the tools they need to make choices that will improve the sustainability of their land.” 

To read more about Lewton's NCR-SARE Youth Educator project, visit the SARE reporting website at: http://sare.org/MySare/ProjectReport.aspx?do=viewProj&pn=YENC08-005

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