Soil Forming Processes

Question 1

What are soil forming processes?

Answer 1

Are the ways in which soil forming factors combine to form soil

Question 2

What is the difference between soil formation and weathering?

Answer 2

A soil forming processes is a building up process and weathering is a breaking down process.

Question 3

What is mature, stable soil?

Answer 3

Soil that has developed horizons by natural soil forming processes

Question 4

What happens in the O horizon

Answer 4

It is the first horizon
It contains humus

Question 5

What happens in the A horizon

Answer 5

It is in the second layer
It is called topsoil
It is darker in colour
It contains many minerals

Question 6

What happens in the E- horizons?

Answer 6

It is the third horizon
It is lighter in colour
Elluviation occurs here
Leaching occurs here
Contains aluminium and iron

Question 7

What occurs in B-horizon

Answer 7

Illuviation takes place
Fourth horizon
It is named subsoil
Enriched with calcium carbonate

Question 8

What occurs in C- horizons?

Answer 8

Just above the bedrock

Question 9

What would have happened if particles of surface soil don’t match with bedrock?

Answer 9

The soil must have been blown away from its original place to another

Question 10

Name factors influencing soil forming processes

Answer 10

Mineralization
Humification
Leaching
Luviation
Plinthite
Bioturbation
Inversion

Question 11

What is mineralization?

Answer 11

Mineralization is the release of minerals from the soil by decomposition.

Question 12

What are the 2 most important micro organisms in the mineralization process?

Answer 12

Bacteria and fungi

Question 13

What is the function of bacteria and fungi in the mineralization process?

Answer 13

They break down simple organic matter into their simplest form or building block

Question 14

What is humification?

Answer 14

Humification is the process whereby micro organisms produce humus through the decomposition process

Question 15

Name 5 agents of humification

Answer 15

Bacteria, fungi, termites, earthworms and ants

Question 16

What is the function of humus?

Answer 16

It binds the soil particles together

Question 17

What is Leaching?

Answer 17

Is it the process where soluble material is taken out of the soil in a solution

Question 18

Which soil is more prone to leaching?

Answer 18

Sandy soil, because water moves through it much faster

Question 19

What is percolation?

Answer 19

Liquid filtering through q substance

Question 20

What is Luviation

Answer 20

It is the downward movement of substances through the soil

Question 21

Name the two types of luviation

Answer 21

Elluviation
Illuviation

Question 22

What is Elluviation

Answer 22

Is the removal of organic and inorganic substances in the soil, is driven by the downward movement of water

Question 23

What is illuviation

Answer 23

Is it the downward movement of material, especially fine particles

Question 24

What does elluviation result in?

Answer 24

The development called podzols

Question 25

What is plinthite?

Answer 25

A horizon of oxidized iron that develops into the subsoil

Question 26

In what places is it prone to happen more?

Answer 26

Places that have fluctuating water tables

Question 27

How does iron in plinthite occur?

Answer 27

When soils become waterlogged, iron in the soil is reduced because of absence of air. When water tables decrease iron in the soil is oxidized. The iron is distributed randomly in the soil.

Question 28

What are the two types of plinthite?

Answer 28

Hard plinthite Soft plinthite

Question 29

Differentiate between hard plinthite and soft plinthite

Answer 29

Soft plinthite is still permeable to rising water whereas Hard plinthite does not allow water to penetrate through it

Question 30

What is inversion?

Answer 30

Are soils that contain high inorganic content and very little organic content

Question 31

Where do inversions occur

Answer 31

In areas where the is distinct wet and dry seasons

Question 32

What are the properties of inversions?

Answer 32

Shrinking and swelling properties

Question 33

What is Bioturbation?

Answer 33

Is the result of disturbance caused by living organisms inside and outside sedimentary

Question 34

What is a cast

Answer 34

Material thrown out into the surface

Question 35

How does bioturbation occur

Answer 35

When organisms leaving in the soil cast out substances and bring in new organisms into the soil. This churns and mixes organisms in the soil.