1. Soil Soil is made of A. weathered rock/ sediments
B. humus- decayed plant and animal matter
C- living organisms- (worms, fungi and insects)

2. Soil Horizons- layers of the soil
A horizon- also called topsoil is made up of dead and decaying plants and animals. This layer is dark in color and rich in nutrients that are used by plants.
B horizon- this layer is lighter in color because there is not any humus. Minerals are washed downward from the A horizon into this layer by a process called leaching.
C horizon – this layer is the parent material containing mostly weathered rock or sediment

3. Soil profiles -side view of the different horizons (layers ) of soil in the ground.

5. Factors that affect soil formation
Parent material-
Type of vegetation- see next slide
Slope of the land
Climate
Time

7. Notice the thicker darker top layer at the bottom of the slope