Soils contain four parts: weathered minerals, organic matter, water and air. All of these different parts work together and effect how plants grow and how the soil can be used. Rocks and minerals weather or break down over time into smaller particles. These particles are called sand, silt, and clay. Sand is the largest soil particle, followed by silt, and clay is the smallest.

Soils are different amounts of sand, silt, and clay mixed together. The kind of mixture is called soil texture. Soil scientists determine soil texture by making something called a soil ribbon.

Supplies

• 3-4 cups of different soils

• Spray bottle

• Bucket of water

• Paper towels or a rag

Let's Do it!

1. To make your own soil ribbon, take an egg-sized soil sample, and spray it with water to lightly moisten it.

2. Mix the soil and water together. If it is too dry, and completely falls apart, spray more water. If it is too wet, add dry soil.

3. When you are trying to figure out what kind of soil texture you have, think about this:

   • Sand tends to have a gritty texture, like salt or sugar, and it falls apart when squeezed into a ball.

   • Soil with a lot of silt has a silky feel, similar to flour.

   • Clay tends to be sticky and greasy, and it easily forms a ball.

   • Most soils have varying amounts of these particles, and will have a combination of the properties.

4. Once you have a moist soil ball, gently press your thumb and push the soil over your forefinger into a ribbon.

5. The longer you can make your ribbon, the higher the clay content. Clayey soil can ribbon out or three-fourths of an inch or greater, Figure 2.

6. If your ribbon is short (less than three-fourths of an inch) and cracks, the soil is considered to have a loamy texture (usually containing varying amounts of sand, silt, and clay).

Talk it Over!

Ask yourself these questions while you are observing your soil:

1. What does the soil feel like?

2. What does the soil look like? Is it heavy? What color is it?

3. Is there evidence of plant material or other living materials?

Soils are composed of particles of different sizes: Sand (.05 to 2 mm), silt (.002 to .05 mm), and clay (smaller than .002 mm). Humus, or decomposed organic matter, is often a part of soils. A soil shimmy is another way to determine what kind of soil you have. Get your dance shoes on and get shaking (with your soil!)

Supplies

• Clear, plastic bottle or jar, or glass jar (just be careful!),

• Soil samples

• Water

• Powdered dish detergent (optional)

• Dancing shoes (optional)

• Ruler (optional)

Let's Do It!

1. Put at least a half cup of soil (from your yard, not from a bag!) into a clear 20-ounce plastic soda bottle.

2. Optionally, add a tablespoon of powdered dish detergent in with the soil.

3. Fill the bottle with water.

4. Secure the bottle cap.

5. Dance around and shake the bottle vigorously for at least two minutes.

6. Place your bottle in a location where it can sit undisturbed for 24 hours. The soil should settle out from bottom to top in layers of sand, silt, clay, organic matter, respectively.

Talk it Over!

1. What happened to the soil in the jars?

2. What type of soil settled out first? Why do you think so?

3. What other things do you notice about your jar?

4. What kind of soil do you think you have?

5. What other ways can you figure out what soil you have?

Supplies

• Trowel or small shovel

• Magnifying boxes or glasses

• Worms

• Damp paper towel

• Toothpick

Let's Do It

Handle with Care: Worms are sensitive to light and they need moisture or will dry out very quickly, so please handle with care and keep a moist paper towel around.

1. Using a small shovel, gently dig a hole in soft soil like a garden, the woods, or under a shrub. Can you find any worms?

2. Take your scoop of soil and put it on a plate with a moist paper towel.

3. Gently move aside the soil to look for any worms. If you can’t find any, keep digging!

4. Once you find a worm, explore the following questions!

• What color is your worm?

• What shape is your worm?

• How does the worm’s skin feel?

• Gently turn your worm over. Is there a difference between the top side and the bottom side?

• Can you tell which end is the front and which end is the tail of the worm?

• Does your earthworm have..

Eyes?

Ears?

Legs?

A Nose?

A Mouth?

• How does your worm move?

• Hold your worm in your hand. What does it do?

• What is the name of your worm?

• Observe your worm with a hand lens. Are there things you can see now that you couldn’t see before? Describe and draw them.

Talk it Over!

1. Why are worms important to life on earth?