What happens to different types of soil in water? How long does it take for the sediments to fall to the bottom?
What You Need
- Small bucket
- Hand shovel
- Jar, clear glass or plastic
- Soil Inventory Sheet (optional)
What You Do
- Discuss the basics of soil.
All soil is composed of sand, silt, and clay. These distinctions are made by particle size only, with sand being the largest and clay the smallest.
Each type of plant has its own needs. Different plants need different soil because they need more or less water, air and minerals.
When you are planning your garden, it is helpful to identify your soil types. This activity is a fun way to study it.
Get more details on this soil activity in our Schoolyard Habitats How-To Guide, on pages 38-39.
Also, here is a worksheet to track your soil observations.
- Go to a place where you’d like to study the soil composition.
It might be somewhere you’d like to plant a garden. Or you might just want to compare the soil in a wet area to the soil in a dry area.
Get about a one cup sample.
- Fill a jar with water.
Remove any leaves, stones or anything from your sample except the basic soil structure. Squish out any clumps. Scoop it into the water-filled jar.
- Observe the jar over time.
Shake the jar vigorously until the soil is suspended.
After one minute measure the amount of soil that has settled with a ruler, this is the sand content.
After one hour measure the amount of soil that has settled, subtract the amount of sand. This is the silt content.
A day later, measure the total amount of soil settled, subtract the amount of sand and silt. This is the clay content of the soil.
Divide the depth of each layer by the total depth of the soil, and then multiply by 100 to get percentages of soil components.
- Another way to study soil components is the Squeeze Test.
Grab a small handful of soil. Make a fist and release.
Sand: If the soil falls apart and feels gritty, it is sand. Sandy soil has quick drainage and low nutrient levels, requiring frequent watering and fertilization.
Silt: If the soil has a slippery texture and slides apart, it has a high percentage of silt. Silty soil has poor drainage and moderate ability to retain nutrients.
Clay: If the soil retains it shape after it is squeezed and is sticky when wet it is mostly clay. Clay is rock-hard when dry; it can store nutrients, but roots and water have difficulty penetrating it.
Loam: Loam is a mixture of all three of these particles. It has a crumbly texture with some grittiness and some stickiness.