Soil Basics
What is soil made of?
Tiny rock particles, organic matter, water, and air.
Which soil feels gritty?
Sand soil
What does a dark soil color usually indicate?
High organic matter content.
What is the top layer of soil called?
Horizon O (organic layer).
Soil covers the Earth’s surface and supports what?
Plant growth
Which soil is smooth and sticky when wet?
Clay soil
Red soil color often means the presence of what?
Iron
Which horizon is also known as topsoil?
Horizon A.
What are the three main soil particle sizes?
Sand, silt, and clay
Which soil drains more slowly than sand but faster than clay?
Silt soil
Grey soils are usually…?
Poorly drained or waterlogged.
Which horizon contains clay and minerals washed down?
Horizon B (subsoil)
Which type of soil has a balanced mix of sand, silt, and clay?
Loam soil.
Which soil property describes how easy soil is to till?
Soil workability
What chart is used to classify soil color?
Munsell color chart.
What is horizon C made of?
Parent material (broken/weathered rock pieces).
How long can it take for one inch of soil to form?
Hundreds to thousands of years.
What tool is used to classify soil into 12 textural classes?
Soil Texture Triangle
Why is soil color important to scientists and farmers?
It provides clues about fertility, drainage, and composition.
Which horizon is solid, unbroken bedrock?
Horizon R.