Lesson 13

Question 1

including flora (plants), fauna (animals) and microorganisms, perform functions that contribute to the soil’s development, structure and productivity.

Answer 1

Soil Biota

Question 2

Plants act on the soil environment by aiding in
structure and porosity.

Answer 2

Soil Flora

Question 3

Soil Flora Cycle

Answer 3

Older Plants Die - Dead Plants - Soil organisms feed on dead plants rotting them down to humus. Humus contains nutrients - Living plants take up nutrients from humus in the soil

Question 4

can remain open for some time after
the root decomposes, allowing an avenue for water and air movement

Answer 4

Root channels

Question 5

act to stabilize soil through aggregation
and intact root systems can decrease soil loss.

Answer 5

Roots

Question 6

the narrow zone of soil directly
surrounding plant roots, is the most biologically active region of the soil

Answer 6

Rhizosphere

Question 7

It contains sloughed root cells and secreted
chemicals (i.e., sugars, organic acids) that provide organisms with food

Answer 7

Rhizosphere

Question 8

work as soil engineers, initiating the
breakdown of dead plant and animal material, ingesting and processing large amounts of soil, burrowing ‘biopores’ for water and air movement, mixing soil layers, and increasing aggregation.

Answer 8

Soil Fauna

Question 9

Important soil fauna

Answer 9

earthworms
insects
nematodes
arthropods and rodents.

Question 10

considered one of the most important soil
fauna

Answer 10

Earth Worms

Question 11

able to build soil by moving
between 1 to 100 tons of subsoil
per acre per year to the surface

Answer 11

Earth Worms

Question 12

shows what a healthy soil needs in the way of soil life

Answer 12

Soil food web

Question 13

An important relationship found in almost all soils and plants, including many crop species

Answer 13

mycorrhizae