Soil Summative Review Flashcards
Silt
a kind of powdery, slippery soil. Holds water. Its grains can only be seen through a magnifying lens.
Humus
Organic substance resulting from decomposed plant and animal matter.
Soil
Loose material that covers much of the Earth
s land surface. Three types of soil are sand, silt and clay.
Sand
Has large grains of rock and feels gritty. Large grains do not stick together so water passes through quickly.
Natural Resources
Any useful material from Earth that is used by people.
conservation
the wise use of natural resources.
Clay
The smallest grain. It’s grains stick together and can be molded with your hands.
Geologists
Scientists who study the Earth’s materials.
Layers of soil
Top soil, subsoil, bedrocks
Top soil
made from humus and clay high in nutrients, making it good for ants.
Subsoil
Layer beneath the topsoil which is mostly clay with very few nutrients.
Bedrocks
The solid rock beneath all soil
Most important characteristic of soil is for __________
plant growth.
Soil forms over many years; it is a _______________ resource
nonrenewable
_________________ can benefit soil by allowing air and water to enter.
Earthworms
