Earth's Changing Surface-Soil, Erosion and Weathering

Crumbly dark mixture of humus, clay and other minerals

(a)  

The B horizon consisting of clay and other particles but little humus

(a)  

Dark colored substance in soil from decayed organic material

• humus

• loam

• topsoil

• bedrock

Soil that is made of equal parts clay, silt and sand.

(a)  

A farmer plants different crops in a field each year

• crop rotation

• crop round-about

• tilling

• conservation plowing

Conservation plowing is where farmers leave dead _____ and ______ of previous years crops to retain moisture and hold the soil in place

(a)  

Farmers plow fields along the curves of slope to help slow runoff of rainfall so it won't wash away the soil

• crop rotation

• contour plowing

• conservation planting

solid layer of rock beneath the soil

(a)  

Measure of how ell soil supports plant growth

(a)  

 Landslides and avalanches are all examples of ____.

• runoff

• mass movement

• soil formation

• mechanical weathering