Grade 3

Underground Worlds: Soil and Water

Learning goals

To identify different types of soil (sand, clay, loam).
To explain how water moves through soil (porosity and permeability).
To describe how plants depend on soil and water.
To investigate how soil filters water.
To explain how structures can prevent erosion.

Materials

Three different soil samples: sand, clay, and garden loam (or potting soil)
Three clear plastic cups (all the same size)
Three additional, larger cups/containers to collect the drained water
Coffee filters
Rubber bands (optional, to secure filters)
Measuring cup(s)
Water
Chart paper
A timer or stopwatch
Small plants or root diagrams
Pictures of a garden, a muddy puddle, a sand dune, and an eroded riverbank

Activity instructions

There are four parts in this activity to be completed:

Introduction
Hands-on activity
Class discussion
Wrap-up activity

Introduction: Minds-on (10 min)

Show pictures of:

A garden
A muddy puddle
A sand dune
A riverbank eroding

Ask:

“Why do plants need soil?”
“What is soil made of?”
“Where does water go when it lands on the ground?”

Hands-on activities (35 mins)

Station 1: The soil drainage race (15 min)

Materials:

Three different soil samples: sand, clay, and garden loam (or potting soil)
Three clear plastic cups (all the same size)
Three additional, larger cups/containers to collect the drained water
Coffee filters
Rubber bands (optional, to secure filters)
Measuring cup(s)
Water
Chart paper
A timer or stopwatch

Instructions

Students will test and observe how water moves through three different soil samples (sand, garden soil and clay).
Poke holes in the bottom of three cups, line them with coffee filters, and fill each with equal amounts of sand, clay, or loam.
Place cups over collection containers. At the same time, pour equal amounts of water (record measured amount) into each cup and start the timer.
Record how long it takes for water to completely drain through the soil sample, noting which soil is fastest and slowest.
Once the water flow stops, measure the water collected in the bottom cups/containers and compare to the original amount of water poured into the cup to see how much water the soil “soaked up.”

Sample chart for recording results:

Amount of water poured in top cup	Soil type	Time / speed	Amount of water collected in bottom cup
	Sand
	Clay
	Loam (garden soil)

Learning concepts:

Sandy soil drains fast
Clay holds water
Loam is balanced

Station 2: Soil as a water filter (10 min)

Materials:

Two plastic cups
Coffee filters
Rubber bands (optional, to secure filters)
Garden soil sample
Water

Instructions:

Line the top of a plastic cup with a coffee filter (use an elastic to secure).
Add some soil into the coffee filter.
Mix dirty water (soil and water) in a cup.
Pour dirty water through soil and coffee filter.
Observe how clear the filtered water becomes.

Learning concepts:

Soil filters water in nature as a part of groundwater systems.

Station 3: Plants, roots and water (10 min)

Students examine the structure of plant roots and investigate how they “take up” water.

Examine real plant roots or diagrams of root systems
Sketch roots and label how they take up water.

Optional challenge:

Build a mini “erosion barrier” (sticks, rocks) and test by pouring water on a soil slope.

Reflection (15 min)

Class discussion

Which soil absorbed water best?

Why do plants need certain types of soil?

How does soil help keep water clean?

Wrap-up activity

Explain one way soil and water work together in the environment.

Videos

Watch and listen to Wally the Worm and Deanna the Water droplet on their water cycle adventure! Wally and Deanna use accurate terminology to describe their journey and explain how water droplets, like Deanna, travel from the sky into the ground, through an aquifer, past rivers and back up into the sky. This book and our new video are the perfect introduction for children of all ages to the water cycle!

This fun song and dances teaches about the water cycle.

Find out what it takes to treat surface water for drinking. Includes a tour of the Region of Waterloo Mannheim Water Treatment Plant.

How we use water towers to move water through the distribution system.

Overview of groundwater words and terminology.