Comparing Soil Samples from different locations

Chris Bakke, Clearbrook-Gonvick School, Clearbrook, MN, based on an original activity developed as an assignement during MnSTEP Inquiry class.
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Summary

In this field investigation, students compare various soil samples taken from specific locations. Students compare samples, record data, create a chart or graph, and journal.

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Learning Goals

This activity is designed for students to create a controlled experiment, using a specific step-by-step procedure (grad standard). Students present their conclusions and observe that when the investigation is repeated, similar results should be expected (grad standard). In addition, this activity is designed for students to develop or practice skills of: observation, cooperation, planning, communication, oral presentation, recording, measuring, and questioning.

Students will observe differences in soil samples: texture, color, smell, etc..

Vocabulary:

-Silt

-Grains

-Pebbles

-Rock

-Fine

-Smooth

-Irregular

Context for Use

Time: 5 day lesson
Prior Knowledge: Knowledge of charts and graphs and record keeping skills.
Activity Focus: The topic of soils could be easily modified to plants, water, insects...

Description and Teaching Materials

Needs to be done in the fall or spring when the ground is soft enough to dig.

Introduction (Day 1):

Materials:

-Variety of soil samples

Put students in groups, each group gets some soil samples (at least 3) and students compare and contrast the samples (texture, color, smell, sight,...)

Students write 5 investigable questions about things they would like to learn about the soil samples ( For example: How are these soil samples different? What makes the color of the soil samples different? Which soil would be best for growing beans? ... Questions should start with "how", "which", "what" etc - but not "why". Why questions will be used for journal prompts as they are often difficult to investigate.

Each group discusses their observations and questions (give time) and student groups then share their top 3 questions. Students write in their journal and drawings on: "why are these soil samples different?"
*Notice that someone asked something like: how are these soil samples different?

Day 2:
Materials:

-Baggies
-Sharpies

Class discussion: "How would we do a soil investigation with our own samples?"
Develop a plan together (something like the following) from class discussion.

Procedure:
1. How deep each location will be - each sampling location needs to be the same depth (for example - soil is taken at the depth of the shovel head at each location)
2. How much soil will be taken as a sample from each location (a cup)
3. Where to take soil samples (class can appear to choose this - if you need permission to dig, it needs to be determined ahead of time!). Determine at least three locations to collect samples from.

Students write a step-by-step procedure that they will follow for collecting samples, examining them, and charting or graphing the data.

Students work in groups of 2-3 to refine the step-by-step procedures into one final copy.

As a class a final plan is worked out, using input from student groups, and posted in the classroom. The entire class will all follow the same procedures.

Label baggies for each location in preparations for sample collection.

Day 3:
Materials:

-Baggies
-Sharpies
-Shovels
-Cup (for measuring)

Class goes on location and collects samples.

Day 4:
Materials:
-Soil samples
-Hand Lenses
-Microscopes

Student's journal: "Why are there differences between the soil samples we collected?"

Students use microscopes and hand lenses to examine a set (one sample from each location) of soil samples that were collected in class. Students each record 4-6 differences that they observe between a set of the samples.

In groups of 2-3 students share their findings with each other. Student groups compare their data and determine a way to chart or graph the best of their results on one chart.

Day 5:
Student groups present their conclusions using their charts or graphs as evidence.

Students journal ideas to help them further differentiate between the soil samples.

As a class, discuss:
"What was the plan for this soil sample investigation?"
(Review the plan developed and posted in class on Day 2 )

For grad standard: students need to observe that each group repeated the same step-by-step procedure and should have gotten similar results.

Teaching Notes and Tips

For grad standard: students need to observe that each group repeated the same step-by-step procedure and should have gotten similar results - they also need to present their conclusions.

Assessment

Day 5:
Student groups present their conclusions using their charts or graphs as evidence.

Standards

5.I.B.1 and 2
The student will perform a controlled experiment using a specific step-by-step procedure and present conclusions supported by the evidence.
The student will observe that when a science investigation or experiment is repeated, a similar result is expected.

References and Resources