6th GRADE NEWEST NOTES (Beyond 2016):.....SOIL

Soil Vocabulary Words

Soil - Soil is a mixture of rock particles, minerals, decayed organic material, water, and air.

Bedrock - The solid layer of rock beneath the soil.

Humus- A dark colored substance that forms as plant and animal remains decay.

Fertility- The ‘fertility’ of soil is a measure of how well the soil supports plant growth.

Loam - Soil that is made up of about equal parts of clay, sand, and silt.

‘pH’ scale - Measures acidity.

A substance with a pH less than 4 is strongly acidic.

A substance with a pH of 7 is neither acidic nor basic (Pure water has a pH of 7)

A substance with a pH greater than 10 is strongly basic

Most garden plants grow best in soil with a pH between 6 and 7.5

Soil horizon - A soil horizon is a layer of soil that differs in color, texture, and composition from the layers above or below it.

C Horizon - The C horizon forms as bedrock begins to weather. The rock breaks up into small pieces.

A Horizon - The A horizon is made of topsoil which is a crumbly, dark brown soil that is a mixture of humus, clay, and other minerals.

B Horizon -The B horizon, often called ‘subsoil’, usually consists of clay and other particles of rock, but little humus. It forms as rainwater washes these materials down from the A horizon.

Decomposers- These are the organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals.

Soil Profile – A vertical section of soil that shows all the different layers