Soil Science Envirothon

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

• topsoil
• undersoil
• subsoil
• bedrock

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

• clay
• sand
• silt
• mud

_______ is the type of soil used most often with plants. It is a mixture of clay, sand, and silt.

• loam
• humus
• mud
• dirt

Humus is.....

• the dead parts of plants and animals in soil.
• A food we eat with pretzels.
• The tiny particles inside of soil
• The roots that come off of a plant and live in soil.

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

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

• Clay soil does not have many nutrients.
• Roots cannot easily push through clay soil.
• Water doesn't drain well through clay.
• All of these choices.

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 layer of soil are these roots growing in?

• subsoil
• topsoil

What is a soil problem all farmers face?

• soil hardening
• soil erosion
• soil spoiling
• soil pollution

Layers of soil are also known as:

• Soil Profiles
• Soil Horizons
• Soil sheets
• Soil cores