The process of wearing down and carrying away rocks.
Erosion
The process that breaks down rock and other substances.
Weathering
The loose, weathered material on earth in which plants can grow.
Soil
A crumbly, dark brown soil that is a mix of humus, clay, and other minerals. Also called the A Horizon.
Topsoil
The management of soil to limit its destruction.
Soil conservation
The wearing away of rock particles carried away by water, ice, wind, or gravity.
Abrasion
The type of weathering in which a rock is physically broken down into another substance.
Mechanical weathering
The solid layer of rock beneath the soil.
Bedrock
A layer of soil that differs in color, texture, or composition from the layers above or below it.
Soil horizon
Anything in the environment that humans use.
Natural resource
The process by which water gets into cracks, explands when it freezes (widening the crack), melts, and repeats the process to force the rock apart.
Frost wedging
The process that breaks down rock through chemical changes.
Chemical weathering
A dark-colored substance that forms as plants and animals decay.
Humus
Soil that usually consists of clay and other particles of rock, but little humus. Often called the "B Horizon".
Subsoil
The planting of different crops in a field each year.
Crop rotation
Describing something that is full of tiny holes which increases its surface area.
Permeable
The process by which iron combines with oxygen.
Oxidation
This is measured by how well soil supports plant growth.
Fertility
A scale which measures how acidic or basic a substance is.
pH Scale
The plowing of fields in line with the slope of the land instead of in straight lines.
Contour plowing
The principle that states that geologic principles that operate today also operated in the past.
Uniformitarianism
Give THREE examples of agents of chemical weathering.
1. Water
2. Oxygen
3. Carbon dioxide
4. Living organisms
5. Acid Rain
Soil that is made of equal parts clay, sand, and silt.
Loam
Organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals.
Decomposers
A type of plowing whereby weeds and stalks of a previous year's crop are plowed inot the ground to help return nutrients to the soil, retain moisture, and hold soil in place.
Conservation plowing