How Soil Forms


Terms in this set (...)

It is a complex mixture of mineral particles, air water, humus and various types of living organisms on Earth's surface in which plants can grow.
soil horizon
A layer of soil that differs in color, texture, and composition from the layers above or below it.
a dark colored substance that forms as plant and animal remains decay.
the organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals.
soil that is made up of equal parts of clay, sand, and silt.
layer of soil below topsoil that has less plant and animal matter than topsoil and contains mostly clay and other materials
the crumbly, topmost layer of soil made up of clay and other minerals and humus (nutrients and decaying plant and animal matter)
rock that makes up Earth's crust; also the solid rock layer beneath the soil
measure of how well soil supports plant growth
pH scale
measures acidity of soil

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