Notes: Soil Formation And Composition printable pdf download

Notes: Soil Formation And Composition

Notes: Soil Formation and Composition

Soil Formation

Soil – The loose, weathered material on Earth’s surface in which

plants can ________.

How is soil formed?

Soil is formed as rock is broken down by _______________ and

mixes with other materials on the surface.

Bedrock – The __________ layer of rock beneath the soil. It

gradually weathers into soil whenever it is exposed.

Soil Composition and Texture

Soil is a mixture of ___________ particles, minerals, decayed

organic material, air, and water.

Humus – Dark colored the decayed organic material in _______;

helps create ______________ in soil for air and water; rich in

elements that plants need

Loam – soil made up of about equal __________ of clay, sand,

and silt; ideal for most plants

Soil Particle Size

Soil Layers

Soil Horizons

Soil horizon – layer of soil that __________ in color and texture

from layers above or below it.

Topsoil – Mixture of humus, _________ and other minerals that

forms the crumbly, topmost layer of soil; the _______ horizon

Subsoil – The layers of soil beneath the ___________ that

contains mostly clay and other minerals; the _______ horizon

Soil

1. Soil is a combination of _____________ and

_________________.

Notes: Soil Formation And Composition