by L. Holt-Taylor, Milford Exempted Village Schools
The Big Ideas
Soil is composed of small pieces of rock and decomposed pieces of plant, animals, and products of plants and animals.
Soils are often found in layers and can be different from place to place.
Each layer has different properties. The layers of some soil are very different than others.
Soil must provide nutrients, water, and air and helps to support the plant.
Four Properties of Soil
Soil color--determined by its make up.
Soil texture--the coarseness or fineness of the soil.
Soil compaction--the amount of air and water in the soil.
Soil nutrients--the ability to support plant growth.
Smaller rocks come from the breakdown of larger rocks through the actions of plants and weather.
Weathering breaks down rock into tiny particles forming sediment.
Weathering is the wearing away of rock because of wind, plants, ice or water. Some changes happen slowly and others more rapidly.
Erosion moves the sediment to other places where it is deposited.
Terms to Know
Soil
A material made of tiny pieces of rock, minerals, and decayed plant and animal matter.
Decomposer
An organism that gets energy by feeding on dead materials and wastes.
Topsoil
Loose rich soil near the top. It holds a lot of humus and minerals. Humus provides many things that plants need.
Subsoil
This layer holds many minerals washed down minerals from the topsoil. You can find clay in this layer.
Bedrock
Below the subsoil are large pieces of weathered rock. Below the weathered rock is rock that has not been weathered.
Sedimentary Rock
Rock that formed when sediments were pressed and cemented together.
Silt
Silt is between sand and clay. Silt feels powdery like flour, soft and velvety, and compacts to some degree. When dry, silt is easily blown by the wind.
Sand
Sand is finely divided rock and mineral particles.
Loam
Loam is made up of even amounts of silt, sand and clay. It is ideal for gardening and contains more nutrients and humus.
Clay
Clay is made of the smallest particles of rock. Water does not flow easily through clay.
Humus
Decaying material in soil.
Weathering
The breakdown and wearing away of rock.
Erosion
The movement of weathered materials by water, wind or ice.
Decayed Layer
This layer contains mostly dead and decaying matter (leaves, twigs, animal remains, and animal wastes.)
Ohio Science Standards for This Unit
Earth Science Benchmark C: Describe the Earth’s resources including rocks, soil, water, air, animals and plants and the ways in which they can be conserved.
Earth Science Indicators
Describe that smaller rocks come from the breakdown of larger rocks through the actions of plants and weather.
Observe and describe the composition of soil (e.g. small pieces of rock and decomposed pieces of plant and animals and products of plants and animals.)
Investigate the properties of soil (i.e., color, texture, capacity to retain water, ability to support plant growth).
Investigate that soils are often found in layers and can be different from place to place.
InteGreat Science: Soil Properties and Weathering
by L. Holt-Taylor, Milford Exempted Village Schools
The Big Ideas
Soil is composed of small pieces of rock and decomposed pieces of plant, animals, and products of plants and animals.
Soils are often found in layers and can be different from place to place.
Each layer has different properties. The layers of some soil are very different than others.
Soil must provide nutrients, water, and air and helps to support the plant.
Four Properties of Soil
Soil color--determined by its make up.
Soil texture--the coarseness or fineness of the soil.
Soil compaction--the amount of air and water in the soil.
Soil nutrients--the ability to support plant growth.
Smaller rocks come from the breakdown of larger rocks through the actions of plants and weather.
Weathering breaks down rock into tiny particles forming sediment.
Weathering is the wearing away of rock because of wind, plants, ice or water. Some changes happen slowly and others more rapidly.
Erosion moves the sediment to other places where it is deposited.
Terms to Know
Ohio Science Standards for This Unit
Earth Science Benchmark C: Describe the Earth’s resources including rocks, soil, water, air, animals and plants and the ways in which they can be conserved.