Teachers and families across the country are facing a new reality of providing opportunities for students to do science through distance and home learning. The Daily Do is one of the ways NSTA is supporting teachers and families with this endeavor. Each weekday, NSTA will share a sensemaking task teachers and families can use to engage their students in authentic, relevant science learning. We encourage families to make time for family science learning (science is a social process!) and are dedicated to helping students and their families find balance between learning science and the day-to-day responsibilities they have to stay healthy and safe.
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Sensemaking is actively trying to figure out how the world works (science) or how to design solutions to problems (engineering). Students do science and engineering through the science and engineering practices. Engaging in these practices necessitates that students be part of a learning community to be able to share ideas, evaluate competing ideas, give and receive critique, and reach consensus. Whether this community of learners is made up of classmates or family members, students and adults build and refine science and engineering knowledge together.
In today's lesson, How do hooved, herding herbivores help the soil?, students engage in science and engineering practices to produce data to help support (or refute) the claim that carefully managing the number and amount of time livestock allowed to graze in an area causes healthy ground cover to grow and flourish.
This lesson is based on ideas presented in the movie Kiss the Ground. The educational version, Kiss the Ground: For Schools (password: school) is freely available to teachers, educators, schools, and community organizers thanks to a generous grant from the Bia Echo Foundation and Triptyk.
View the How do hooved, herding herbivores help the soil? NGSS table to see the elements of the three dimensions targeted in this lesson.
*Use soil that packs well; seeds placed on top of packed surface should lie on the surface and be able to be easily washed and/or blown away.
Create a space to store the planted containers. This may be indoors or outdoors, depending on the school setting and time of year. It is okay if the containers have to be distributed to multiple classrooms as long as individual groups' containers are placed together.
Tell students you have a puzzling phenomenon to share with them! Show students the photographs of the same location in the Republic of Zimbabwe taken nine years apart. (If your students are unfamiliar with the countries of South Africa, point out the location of Zimbabwe on a map.) Give students time in the alone zone (independent thinking time) to compare the two pictures and record any changes they observe. As you move around the room, encourage students to describe the changes they observe in as much detail as they can. For example, if students record more plants, you might ask them, "How many different kinds of plants do you see in the Year 0 picture? Which kinds of plants increased the most between Year 0 and Year 9?" and "Are there any kinds of plants in the Year 9 picture that are not in the Year 0 picture?"
Ask students to share their observations with a partner; make sure to tell students they may add changes their partner noticed to their own list.
Bring students back together. Invite students to share a change they noticed (or their partner noticed) with the class. Record students' observations in a public space.
Tell students, "Between the time these pictures were taken, a Zimbabwean scientist, Allan Savory, and his team brought cattle to this location twice each year and allowed them to graze for three days. No cattle or other large animals were allowed on the land during the rest of the year."
Pause, then ask students, "How many times did cattle visit this land in nine years?" Ask students to turn and talk with a partner before inviting them to share their answer with the class. (18 visits) You might next ask, "How many total days did cattle graze on this land in nine years?" Again, ask students to share their answer with their partner before asking for a volunteer to share their answer with the whole class. (54 days)
Location in Zimbabwe not managed for grazing (time stamp 30:40)
Location in the same geographic area as the one pictured at left after managed for grazing for nine years (time stamp 31:07)
Share two more photographs (above) with students. Make sure to give them the following information about these photographs:
Allow students time, working in pairs, to compare the location B and C photographs and record differences between the two locations. Next, assign student pairs to small groups and ask them to create a group list of differences between locations B and C. Ask students, "What patterns do you notice in your observations of locations A, B, and C?" Give students time to work with their group members to identify patterns in their observations (data).
Bring students back together and ask them to share patterns they identified in their observations. Students will likely identify the following patterns:
Tell students, "Allen Savory, the Zimbabwean scientist, noticed the same patterns you did and made this claim: The hooves of the cattle are what cause the grass and other plants to grow."
You might choose to share a short clip, 30:30–32:40, from Kiss the Ground: For Schools (password: school) to introduce students to Allan Savory and his research on holistic management.
Guidance. Sharing the video clip from Kiss the Ground: For Schools with upper-elementary students.
Show students photographs of cattle hooves and ask, "How do you think the hooves of cattle cause grass and other plants to grow on land managed for grazing?" Give students alone zone time to record their thinking using words, pictures, and symbols. As you move around the room, consider asking students some of the following questions to move their thinking deeper:
Ask students to use their models to predict how hooved, herding herbivores (cattle) cause the grass to grow on land managed for grazing. Then instruct students to return to their small groups and share their predictions. Do not invite students to share with the whole class at this time.
Provide each small group the following materials*:
*If you have more materials readily available, provide each small group twice this amount of materials so that each student is responsible for preparing one container of seeds.
Share the following instructions with students:
Bring the students back together. Say to students, "Each group will have one container representing land managed for grazing and one container representing land that is not managed for grazing. Right now, we have tightly packed soil in both containers. Which type of land do our containers represent?" Students likely will all agree that both containers are like land that is not managed for grazing.
Next, ask students, "How should we change one of our containers to represent land managed for grazing? That is, land that a hooved herd of cattle has walked over?" Ask students to quickly turn and share ideas with their group members, then bring the class back together. Invite groups to share their ideas. Students will likely suggest using the plastic knife to cut into the soil like the hooves of cattle do. You might as a class decide how many cuts to make, how deep to make the cuts, and whether or not the cuts should all be in the same direction. Give students time to make the cuts after the class has reached consensus.
Ask students, "What do we need to keep the same between our two cups? That is, how can we make sure our test to see which container grows the most radish seeds is fair?" Again, ask students to discuss this question with their group members. Bring the students back together and ask groups to volunteer their ideas. Students will likely say they should put the same number of seeds in each cup, place the seeds in the same locations in both cups, give each cup the same amount of water, and place the cups in the same location in the room (or outside depending on the school setting and the season).
Allow students to place their seeds in the containers. Before students add water, ask them to draw each container, describing in words, pictures, and symbols the shape of the ground surface and the placement of each seed. Then instruct students to gently water the seeds (according to package directions). Some of the seeds may be washed off one or both surfaces; this is acceptable. These seeds should not be replaced. Ask students to record their observations.
Ask students, "What types of data should we collect, and how should we measure each type?" Give students time in the alone zone to record their ideas, then ask them to share their ideas with their group. As you walk around the room, listen for students to share ideas about recording how many seeds are sprouted (count them), the color of the sprouts (light green, dark green, brown); how tall the sprouts are (use a ruler); and the location of the sprouted seeds (show on a drawing). If cameras are available, students may suggest taking pictures of the containers as well.
Bring students back together and ask for volunteers to share their ideas. Make sure to call on the groups who shared the ideas you were listening for first. You might collaboratively work to create a table to record data. You might also decide how often you will collect data.
Allow the investigation to continue at least a few days after the last class radish seed has sprouted.
Instruct student groups to represent their data on a group poster. You might choose to provide students a template for a data table and/or graph or allow students to choose how to represent their group data. Ask students to include on their poster any patterns they identify in their data.
Display group posters around the room. Consider using a "three stray, one stays" gallery walk strategy; that is, one student remains with the group poster as the other group members move from group poster to group poster. Tell the students who "stray" to remain at each poster until you give them a signal to move. As students move from poster to poster, they should record at least one similarity and one difference between their own data and the data represented on the group poster they are observing. Make sure students note the group number or name when recording similarities and differences.
Give each group of students the opportunity to visit at least three posters before returning to their own group's poster. Ask students, "What patterns do you observe in the class data? Share your ideas with your group." Allow students time to first share with the student who "stayed" with their own poster the similarities and differences they observed between their group data and other groups' data. Then move the groups to identifying patterns in the class data.
Students may notice no patterns exist in the class data or that the containers representing land not managed for grazing grew more and/or higher and/or greener radishes than the containers representing land that hooved, herding herbivores walked across. Although students may become anxious because these are not the expected results, it creates an opportunity to discuss experimental design, number of trials, and the nature of science (they may find they get the same unexpected results after revising the investigation).
Provide students time in the alone zone to compare the results of the class investigation with their predicted results. You might ask them to complete a self-reflection using the following sentence stem:
I used to think ____, but now I think ____ because....
You might choose to collect students' reflections or give them time to share their thinking with their group.
Remind students of the claim made by Allan Savory: The hooves of the cattle are what causes the grass and other plants to grow. Then guide students in a brief building understanding discussion using one or more of the following prompts:
To conclude this lesson, you might share some current headlines about hooved, herding herbivores being used to regenerate soil, like the one published in the Star Tribune on September 8, 2020: "Are Bison theKey to Bringing Back Minnesota Prairies?"
KISS THE GROUND: FOR SCHOOLS—available now for free to all schools, students, teachers, and community educators—is a 45-minute-long educational version of the critically praised exo-documentary, KISS THE GROUND, produced and directed by Sundance award-winning documentarians Josh and Rebecca Tickell. KISS THE GROUND: FOR SCHOOLS has new scenes not in the feature film, including a series of person-on-the-street interviews with Rosario Dawson and a scene in which Tony Tenfingers, a Lakota Elder, describes the importance of the once-prevalent buffalo for Native American peoples. KISS THE GROUND: FOR SCHOOLS is also available with subtitles in 18 languages including English Closed Captions, Spanish, Mandarin, and Hindi.
NSTA has created a How do hooved, herding herbivores help the soil? collection of resources to support teachers and families using this task. If you're an NSTA member, you can add this collection to your library by clicking + Add to Library, located near the top of the page.
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