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Spring 1996

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Program turns kids on to science

The river runs through it

Down and dirty: Soil testing

The lawn rangers

F olks in Dakota County, Minn., take great pride in their homes. They groom their lawns, prune their shrubs and tend their trees. Unfortunately, the same lawn fertilizers (organic or chemical) that give rise to luxurious sod can spell disaster for streams and lakes. Runoff from residential areas, high in phosphorus and nitrates, can wash fertilizer applied to lawns into storm sewers and impoundments. Those same chemicals can find their way into ponds and lakes via streams, upsetting the natural balance and endangering aquatic life. In the worst case scenario, fertilizer nutrients can cause eutrophication, where algae clogs a pond and dissolved oxygen is no longer available to sustain fish or macroinvertebrates.

Thanks to an interagency cooperative program based in Farmington, Dakota County lakes and ponds are receiving a lot of attention from teachers and students in the towns of Burnsville, Eagan, Apple Valley, Lakeville, Rosemount, Hastings, South St. Paul and Farmington. The new program, designed to help cities manage and protect local water while alerting citizens to the effects of over-fertilization, is underway in this region located south of the Minneapolis-St. Paul metropolitan area. According to Charlotte Shover, coordinator for the Dakota County Environmental Education Program, Hach test kits were distributed to teachers in a total of 18 junior, senior and alternative high schools for use in monitoring the water quality of local water bodies. Students are testing for dissolved oxygen, nitrogen, ammonia and phosphorus levels, and reporting their results to city councils. Students learn about urban pressures on water bodies, plus they're learning about water quality testing, biology, chemistry and public relations.

"Local watershed management organizations identified priority water bodies in sensitive

subwatersheds," says Shover. "We followed up with activities to raise awareness about the impact of human populations on those water bodies, like baseline surveys, soil tests on lawns, storm drain stenciling and water quality testing."

Shover continues, "We identified a lead teacher in every school and gave them test kits along with some money for transporting kids to the testing sites. Our first priority was building a relationship between the cities and the schools to look at local water quality. Unless these people spend some time together, working together effectively seemed pretty unlikely.

"So during the fall, we conducted an all day training session with 25 teachers and city staff members. They trained each other about running tests and collecting data in a useable format. In addition to creating partnerships, it increased expertise among city staff and teachers interested in improving the county's water quality."

Why did Dakota County choose Hach test kits? "Cliff Jacobsen, one of our local teachers, authored the Water, Water Everywhere curriculum for Hach Company," replies Shover, "and he recommends Hach products. Plus we use the Field Manual for Water Quality Monitoring* as a reference, and it also recommends using Hach analysis systems."

And how do students respond to the program? "A teacher called me yesterday to rave about how pleased he was with a trip to a local lake. The kids liked the hands-on aspect of water quality testing. And even students who were less enthusiastic about science seemed more motivated when they were out in field."

Coordinator Shover has plans beyond testing lakes and ponds. "We're encouraging schools to participate in monitoring the Minnesota and Mississippi Rivers and their tributaries. Schools can build programs based on the Illinois Rivers Project out of Southern Illinois University." The Rivers Project, located at the Edwardsville campus, has the Mississippi, Wabash, Des Plaines, Green, Kaskaskia and other rivers under scrutiny. With literally hundreds of helping hands, they're showing students in action--thinking globally and acting locally.

* Mitchell, Mark K., and Stapp, William, Field Manual for Water Quality Monitoring, Thomson-Shore, Inc., Dexter, Michigan.

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The lawn rangers

 

The river runs through it

Down and dirty: Soil testing

Program turns kids on to science

Ask a group of junior high school students how they spent their summer vacation, and you'll get an assortment of answers.

"Played video games."
"Babysat my sisters."
"Practiced the clarinet."
"Stayed with my grandma on the farm."
"....I dunno. Just hung out, I guess."

Pose that same question to a group of eighth graders from central Texas, and you'd hear,

"Identified endangered species in a river ecosystem."
"Used chromatography to view ink constituents."
"Lived in a college residence hall for a month and made 50 new friends."
"Tested natural springs for carbonate ions, nitrates, phosphorus and dissolved oxygen."

It's easy to guess which group had the more memorable and enriching experience. The Texas teens took advantage of an exciting program conducted by Southwest Texas State University in San Marcos. The Summer Science Program, funded in part by the National Science Foundation and facilitated by the Edwards Aquifer Research and Data Center (EARDC), recruited disadvantaged youth who expressed an interest in science. Drawn from a five-county area, the students lived on campus and attended classes in physics, aquatic biology, computer skills, water chemistry and math.

"They were wonderful students," according to Dr. Glenn Longley, EARDC director. "This program is part of our Education Center's mission to improve public understanding of the Edwards Aquifer. We want to educate citizens about the aquifer, water conservation and endangered habitat issues. These young people were very enthusiastic and involved -- they learned about the aquifer, groundwater, water sampling, collecting plant and animal specimens from the San Marcos River, and identifying invertebrate species microscopically. We look forward to having another group next summer."

The Summer Science Program was staffed by local teachers from the public school system. One teacher, Evelyn Barrett, echoed Longley's enthusiasm. "I taught water chemistry for 90 minutes every day and these kids worked hard. We learned a lot about the Edwards Aquifer water characteristics and studied a spring-fed river. With Hach test kits, I was able to take the kids outdoors and give them hands-on experience running the same tests professionals use."

The youngsters collected samples from the Edwards Aquifer and a spring-fed river. After running tests onsite for carbonate ions, nitrates, phosphates, dissolved oxygen and pH, the students repeated the same tests in the laboratory. "The kids liked the colorimetric chemistry from the Hach test kits," she says. "It's more exciting to see a color change during a reaction than just read a number off a lab instrument," she explains.

Why study the Edwards Aquifer? Designated by the USEPA as the sole source drinking water supply for San Antonio and the Austin-San Antonio corridor, the aquifer is a unique carbonate aquifer made up of porous, permeable limestone. Springs from the aquifer feed several rivers and support the habitat for at least four endangered species. Stretching for some 160 miles, it covers most of five counties in south central Texas and is vital to the agricultural, recreational, and industrial economy of the region. (To find out more about the Edwards Aquifer, visit EARDC's Web site at http://www.eardc.swt.edu/ EA-Introduction.html).

During the academic year, Barrett teaches chemistry at San Marcos High School. "At first, it was a bit of a challenge for me, shifting gears to teach younger students. But I'll be back next summer.

"It's such a thrill to see the lights go on in kids' eyes when they finally grasp a complicated idea. This program really turned some kids on to science. And that's the best part," she says.

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The lawn rangers

Program turns kids on to science

 

Down and dirty: Soil testing

The river runs through it

It starts out modestly enough, near a little Montana town called Trident. After wending its way north for a few hundred miles, it rushes east and roars across North Dakota, picking up momentum from streams with names like the Little Muddy, Tobacco Garden and Cannonball. After an abrupt loop to the south, it cups itself around the east edge of the Badlands. And then, after twisting and turning on itself again and again out in the vast prairies of the midwest, it snakes sharply toward the rising sun, rushing for its appointment with Ole Man River. By the time it reaches St. Louis, the roaring ribbon has been transformed into a lumbering giant, and it loses itself, lazy and placid, in the Mississippi.

The mighty Missouri River is a national treasure cherished by all who live along its banks. Protecting the river and monitoring its well-being are the central focus of an innovative science program in South Dakota's capital city, Pierre.

At the South Dakota Discovery Center and Aquarium, a K-12 integrative science program is in its third year, guiding youngsters in the study of water ecology. With a $175,000 grant awarded by the Howard Hughes Medical Institute, students are learning about water quality and its effect on plants and animals, the biological communities of wetlands, the ecology of the Missouri River Basin, and advanced topics in high school biology. As a part of the Discovery Center's program, students are measuring the levels of dissolved oxygen, phosphates, nitrates, pH, carbon dioxide, and ammonia in the Missouri River that flows just 100 yards from the Center's back door. Using Hach color cube and color wheel test kits, youngsters are able to obtain accurate, reliable data even with little testing experience. According to Education Director Terry Lewis, once students learn how to run tests at the Center, they take the kits back to their schools where they collect water quality data on a different segment of the river. Lewis hopes eventually to create an online network for data collection and analysis, so participants can identify trends and work together to mitigate the factors that contribute to river degradation. While some enthusiastic students take the kits home to test lakes and well water, the major thrust of the program centers on the Missouri River ecosystem.

Lewis travels all over the state in the Center's van, bringing a scientific awareness program to more than 3700 students last year. Another 4800 students visited the Center, some coming from rural and Indian reservation areas hundreds of miles away. "Kids bring their sleeping bags and spend the night in the Center. We use the test kits and look at the biology of the Missouri River. The kids are so excited, so totally engrossed. Sometimes they don't even want to take breaks."

Lewis recommends the free training at the Hach Technical Training Center, and four teachers have followed his advice. "Two attended the Science Educator class and two others went to the Microbiology class. As a result, we plan to start testing for fecal coliforms soon."

Lewis credits Hach test kits with making teachers and students more aware of water quality degradation in the Missouri River. "We're not interested in testing or collecting data for its own sake," says Lewis. "These kids take on real issues in their communities. They want to do real science. And they can share results from longitudinal studies with community leaders, public agencies and other river watch groups."

Working with youngsters keeps Lewis on his toes. "Because the river is always changing, ecology is hard to teach," he says. "To be effective, to be relevant, it has to incorporate biology, chemistry, earth science, physics, social studies, English, math and art. But that's what makes it so interesting too. And kids quickly catch on that science is really a process, not just a collection of facts."

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The lawn rangers

Program turns kids on to science

The river runs through it

Down and dirty: Soil testing

By Jim Schuth

It's official-- the earth has passed its capacity to support the current population. With the world population anticipated at 7.9 billion by the year 2020, the call for increased production from farm land will become more pressing. Recognizing the role that agriculture and soil productivity play in sustaining human populations, Teaching Water Science will take an in-depth look at soil analysis. This article will focus on texture estimation: Future articles will explore analyzing soil pH, fertility factors and enhancements that increase productivity.

Soil testing gives you an opportunity to do some teaching of analysis as it relates to agricultural production and environmental quality. Here's an exercise you can do in one class period with materials and equipment you already have on hand. Using the chart, students will be able to characterize a soil sample as either clay, clay loam or loam. That's useful information for diagnostic testing which can predict fertility and/or productivity problems.

Life-giving soil

Soil is a complex material made of disintegrated rocks and decayed organic material which should provide nutrients, moisture and support for land plants. It is a system composed of solids (minerals and organic materials), liquid (water) and gas (air). Soils are usually characterized by their physical and chemical properties. These properties can help determine how productive the soil will be. One important physical property is texture.

Texture is the relative proportions of sand, silt and clay present in the sample. Evaluating soil texture using the texture estimation method is easy and can be done without any special equipment.

Texture estimation method

Collect soil from several different areas in your community. Take it from the root zone rather than from the surface. Immediately remove all vegetable material, large rocks and pebbles. Then, air dry it thoroughly and grind it as fine as possible.

Make approximately 25 grams of each soil sample available to your students. Have a small container of water nearby. After following the directions on the flow chart (Figure 1), your students should be able to characterize each sample as either clay, loam or clay loam. Use the Soil Texture Estimation Triangle (Figure 2) to help students visualize and recall the relationships among the various types of soil. Figure 3 enables your students to see the kinds of management issues that result from soil types.

Figure 3. Management problems with various soil textures
  Coarse
(Sandy)
Medium
(Loamy)
Fine
(Clay like)
Erosion Management
  Water Low High Low- Medium
  Wind High Low Moderate
Water Management
  Water holding capacity Low Medium High
  Infiltration Rapid Medium-Slow Rapid when dry, slow when wet
  Percolation Excessive Good Fair-Poor
Tillage Management
  Horsepower requirement Low Medium High
  Tillability Easy Medium Difficult
Fertility Management
  Potential nutrient imbalance High Moderate-Low Low
  Chemical reccomendations Low Medium High
  Areation Good Moderate Poor

Editor's note: Jim Schuth, instructor at the Hach Technical Training Center, demonstrates environmental testing during the free, three-day Science Educator's Workshops held during the summer.

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