Questions

Question 1

Which three soil properties control available water?

Answer 1

• Pore sizes
• Structure
• Organic matter

Question 2

What is porosity and how does the structure influence this?

Answer 2

• Porosity is the pore space in soil between mineral particles (and solid organic matter) filled with either air or water.
• Soil structure influences porosity because porosity depends on the size of the pores and soil structure includes the size of the pores.

Question 3

How are gley soils formed?

Answer 3

Gleying: saturation of the soil pores with water, leading to grey and/or red-brownish colourations.

Question 4

How are podzols formed?

Answer 4

chemical and physical processes of leaching transport, and precipitation of humus with iron and/or aluminium.

Question 5

Why is it important to know a soil’s pH?

Answer 5

Soil pH affects the number of nutrients and chemicals that are soluble in soil water, and therefore the amount of nutrients available to plants.

Question 6

What are the jobs of different bacteria?

Answer 6

1. Decomposers: decomposition of organic material when moister levels are high.
2. Nitrogen fixers: Fix nitrogen in the soil by inoculating legume seeds.
3. Disease suppressors: disease suppression.
4. Aerobes and anaerobes: produce toxic compounds that limit root growth and cause root diseases. 5. Actinobacteria: breaking down humates and humic acids in soils.
5. Sulfur oxidizers: convert sulfides into sulfates

Question 7

What is the relation between soil biology and SOM?

Answer 7

Soil organic matter plays a vital part in enhancing soil fertility and quality

Question 8

How to increase soil health?

Answer 8

Limit disturbance
Keep it covered
Increase diversity
Keep a live root
Limit pesticides
Address compaction
Implement strategic grazing

Question 9

What are the factors of land formation?

Answer 9

Weathering starts and bedrock starts to disintegrate
Organic matter disintegrates
Water percolates horizons form
A deeper profile is created, more humus, and a thicker horizon

Question 10

What are the soil components?

Answer 10

Pore space:
20-30% water
20-30% air (gasses)

Soil solid:
45% minerals
5% organic matter

Question 11

Explain the chemical and biological processes in soil formation and degradation

Answer 11

Chemical:
Transport of primary to secondary minerals
Chemically different
Biological:
Impact of Soil organisms
Tree roots growth in cracks

Question 12

Name and give characteristics of four factors related to soil degradation

Answer 12

1. Gleying: saturation of pores with water -> colouration
2. podolization: the chemical and physical process of leaching
3. browning: chemical and biological process in sandy soils with create erosion of iron -
   > rusty colouring
4. Clay redistribution: chemical and physical mobilization transport and precipitating of clay