Hi! I have a fun soil composition activity I have incorporated into lessons to help students visualize how particle sizes vary with clay, silt, and sand, and how water travels through soil with different compositions. I can't remember where I originally found it so if anyone knows who to credit, please share!
Before this game I usually start by sharing samples of clay, silt, and sand that learners can touch, rub between their fingers, and look at with hand lenses or under a microscope.
Activity: Particle Passage
Time: 15 minutes
Group Size: 7+ participants and 1 facilitator
Space: Outdoor field or other area where participants can run between two start and finish lines.
Designate half the group as water and the other half as soil. Colorful play scarves can be a fun way to visually distinguish groups! Instruct water particle group to form a line against a fence or structure. About 20 feet away, instruct soil particle group to line up facing the water particle group. Discuss expectations about safety and body awareness.
Round 1: Sand particles
Soil particle group stands in a line with their arms fully extended horizontally, with fingertips touching their neighbors'. There should be enough space between each participant for the water particle group to duck through beneath their arms and run to the other side when the instructor says Go!
Round 2: Silt particles
Soil particle group stands in a line with their hands on their hips, arms bent, with their elbows touching their neighbors'. It is a little more challenging for the water particle group to pass through the line of soil particles when the instructor says Go!
Round 3: Clay particles
Soil particle group stands shoulder to shoulder in a line. It should be very challenging for the water particle group to pass through the line of soil particles when the instructor says Go!
Round 4: Mix it up!
Soil particle group stands in a line with various poses and distances between each person. If you know the ratios of your soil composition, the group could do some math to figure out how many of each particle size there should be to represent your soil.
An ideal loam composition is 20% clay, 40% silt, and 40% sand.
Wrap up with a group reflection. Which pose representing which particle size was easiest for the water to travel through?
How much water traveled through in each round? You could make some math connections by recording and graphing the results from each round.
An extension of this lesson could be measuring the ratios of your soil using a shaken and settled clear jar full of soil and water. Another connection could be made building erosion models and measuring how much soil is swept away by water under different conditions.
Happy gardening!
Farmer Clary
On Wednesday, September 17, 2025 at 2:44:39 PM UTC-7 Sherman Garden wrote: