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Soil formation begins with the weathering of
litter
bedrock
the A horizon
Soil that is rich in humus has high
fertility.
Water content.
sand content.
When earthworms add their wastes to the soil, then die and decay in the soil, they are contributing to the formation of
silt.
litter.
humus.
Living organisms in soil help to
slow the rate of soil formation.
build up the C horizon.
mix the soil and make humus.
Decomposers are the soil organisms that
store moisture in the soil.
break down and digest the remains of dead organisms.
make spaces in the soil for air and water.
Soil is a valuable resource because it
is important to all living things on land.
contains sand and gravel.
is rich in decomposers.
What can cause the loss of soil that is not protected by plant cover?
chemical weathering
erosion by water or wind
mechanical weathering
Most of the work of mixing humus within the soil is done by
fungi.
ants.
earthworms.
A permeable rock weathers easily because it
is made up of small particles.
contains many small, connected airspaces.
is made up of only one mineral.
In which soil layer would you find loam that is rich in humus
A horizon.
B horizon.
C horizon.
The texture, or particle size, of soil determines
soil fertility.
whether the soil is topsoil or subsoil.
how much air and water the soil can hold.
The type of soil called loam is made up of
pure humus.
mostly clay.
nearly equal amounts of silt, sand, and clay.
In a cross section of soil, the B horizon consists of
clay, minerals, and little humus.
humus only.
partly weathered rock.
