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Soil stories – separating soil and estimating soil texture

SCIENCE
An activity that explores natural features and resources through an examination of the composition of soil.

Science Curriculum connections
Level 1 & 2Explore and describe natural features and resources. Observe, describe, and compare physical and chemical properties of common materials and changes that occur when materials are mixed, heated, or cooled.
Level 3 & 4Appreciate that water, air, rocks and soil, and life forms make up our planet and recognise that these are also Earth’s resources.
Level 4Begin to use a range of scientific symbols, conventions, and vocabulary
Level 5Investigate the composition, structure, and features of the geosphere, hydrosphere, and atmosphere. Investigate the interdependence of living things (including humans) in an ecosystem.

Learning materials

  • clear plastic/glass jar with a lid
  • soil sample
  • large spoon or trowel
  • water
  • coloured pencils/crayons
  • paper
  • permanent marker
  • laundry detergent

Introduction

  • When looking at your garden, what types of living creatures can you see and/or what evidence of living creatures can you find? Write down your observations.
  • Ask your students where they think trees and plants get their nutrients from, ‘How do plants get fed?’ – There are several layers of soil that provide energy to plants and trees.

Activities and teaching strategies

  1. Make a ‘soil shake’ to illustrate and identify the different particle sizes in soil. Using a trowel or large spoon, collect a soil sample from your garden.
  2. Fill the jar half full with soil and add enough water to give the soil a mud consistency. Mark the level of soil on the jar.
  3. Predict what will happen when you shake it up and then let it sit for a few hours. Answer the following questions,
    a) How many layers will form?
    b) Which layer will be the thickest? Thinnest? Why?
  4. Add a pinch of laundry detergent to help the soil components separate well. Shake the mixture thoroughly.
  5. Levels 1-6: After 2-3 hours, see what becomes visible.
    a) Describe what you see. Create a soil composition diagram by drawing the jar of soil and colouring the different layers. From the bottom up, you may need terms such as gravel, sand, silt, clay, water and organic matter.
  6. Levels 4-6: After 40 seconds mark the level of soil on the jar to identify the sand portion. After 6 hours, mark the level of soil on the jar and the difference between the two marks will represent the silt component.
  • Measure the depth of each mark by calculating the percentage of sand, silt and clay.  The difference between the highest mark and the silt mark represents the clay fraction. 
  • Classify your soil’s texture by using the soil textural triangle.
  • What are the best uses for your soil sample?  

Extensions

Levels 1-6Test a soil sample from a new area and compare the two jars.
a) Which layer is the thickest in each? Which is the thinnest?
b) What factors contribute to the soil samples being different?
c) Classify your soil sample (e.g. Sandy loam).
d) What living creatures would you thrive best in this type of soil and why?
Levels 5-6a) Watch the following video to learn about soil profiles.
How are top soil and sub soil formed?
In which layer of soil do plants grow?
b) Research soil profiles in your area and identify the soil horizons: R (bedrock), C (Parent Material), B (Subsoil), A (Topsoil), O (Organic). Based on your sample, which horizon would the thickest? Thinnest?
c) What natural events and human interactions can you think of that might have impacted on the soil profile in your area?

References

Cornwell University. (2010). Competency Area 2: Basic concepts of soil fertility – Northeast Region Certified Crop Advisor (NRCCA) study resources. Retrieved on 9 April 2020 from https://nrcca.cals.cornell.edu/nutrient/CA2/CA0212.php

Ducksters Education Site. (2020). Earth science for kids: Soil. Retrieved on 10 April 2020 from https://www.ducksters.com/science/earth_science/soil_science.php.

Food and Agriculture Organization of the United Nations. (January 2017). Soil experiments for children. Retrieved on 5 April 2020 from http://www.fao.org/3/a-i7957e.pdf.
MakeMeGenius. (2020). Soil profile, soil layers. Retrieved on 10 April 2020 from https://www.youtube.com/watch?v=R0MEVLTsvL8.

Project Learning Tree Organisation. (2020). Family activity: Soil stories – Project Learning Tree. Retrieved on 5 April 2020 from https://www.plt.org/family-activity/soil-stories/>

PREPARED FOR THE EDUCATION HUB BY

Rachel Williamson-Dean

Rachel Williamson-Dean is an experienced secondary school teacher, who has lived and taught in North America, the United Kingdom, Europe and Asia. She has a Master of Public and Population Health Degree (MPH – Dist) and a PhD in Health Education. Over the past ten years Rachel has worked with students and school leaders across New Zealand, including leading the digital literacy programme, The Summer Learning Journey, for which she received the NEXT Woman of the Year in Education 2018 award. 

By Rachel Williamson-Dean