Introduction to Soil

Which of the following is NOT one of the three types of soil?

• clay
• sand
• silt
• mud

Are there minerals in soil?

• Yes
• No

Ellen grabs a topsoil sample in her hand. She rolls it into a ball. The soil feels gritty and the ball falls apart. What part of the topsoil most likely made the topsoil feel gritty?

• clay
• sand
• silt
• humus

You dig a small hole in the soil and the next day it rains. The hole fills with water, but does not empty even after several days of dry weather. What is the soil mostly made of?

• clay
• sand
• humus
• silt

The texture of soil depends mainly on

• the types of plants that grow in the soil.
• the size of the particles in the soil.
• the color of the soil.
• the number of worms in the soil.

Which of the following best describes soil erosion?

• A.  the breakdown of soil by chemicals
• A.  the improvement of soil quality by fertilizers
• A.  the breakdown of soil by drought
• A.  the movement of soil by wind or water

Many plants cannot grow in sandy soil. Why is this true?

• Sandy soil does not hold enough water.
• Oxygen cannot pass through sandy soil.
• Roots cannot easily push through clay soil.
• Sandy soil has too many nutrients.

Which type of soil can hold the greatest amount of water?

• Sand, because it has the biggest particles. 
• Silt, because its particles are smaller than sand. 
• Clay, because its particles are very small. 
• Loam, because it is a combination of different types of soil. 

Where do most plants and animals live?

• Subsoil
• Topsoil
• Bedrock
• Loam

What is soil a mixture of?

• dirt and leaves
• rocks and water
• air and food
• rock particles, minerals,decayed organic material, air and water