Introduction to soil

Question 1

What is the basic composition of soil?

Answer 1

Minerals or rock particles – 45%
Water – 25%
Air – 25%
Organic matter such as leaves – 5%

Question 2

How many years does it take to produce 10mm of soil ?

Answer 2

100 - 1000 years

Question 2

How many years does it take to produce 10mm of soil ?

Answer 2

100 - 1000 years

Question 3

4 Horizons of soil in order?

Answer 3

1.O
2.A
3.B
4.C

Question 4

Gelisols

Answer 4

contain permafrost (found in Arctic, Antarctic, extremely high elevations

Question 5

Histosols

Answer 5

organic, wet “muck” (found in old swampy areas, commonly saturated year-round)

Question 6

Spodosols

Answer 6

sandy, acidic (found in conifer forests where it rains a lot)

Question 7

Andisols

Answer 7

volcanic ash (found wherever there have been volcanoes)

Question 8

Oxisols

Answer 8

highly weathered, low fertility (found in tropic/subtropic regions that have been stable for a long time eg Brazil)

Question 9

Vertisols:

Answer 9

shrink and swell (found where soils are rich in “expansive” clay, crack can be more than a meter deep eg Texas)

Question 10

Aridisols

Answer 10

very dry

Question 11

Ultisols

Answer 11

weathered, humid areas (not very active soils, older soils)

Question 12

Ah

Answer 12

Due to biological activity, organic matter has accumulated in this horizon resulting in a Ah layer.

Question 13

Ae

Answer 13

Horizon that is identifiable by the absence of clay, iron, aluminum and organic matter, resulting in a Ae layer

Question 14

Bf

Answer 14

Enriched with clay, iron, aluminum or humus, resulting in a Bf layer.

Question 15

Bm

Answer 15

An alteration by hydrolysis, reduction or oxidation to give a change in color or structure from above or below. Resulting in a Bm layer.

Question 16

Cation exchange capacity

Answer 16

Total number of cations a soil can retain, this increases with higher levels of clay, the higher the number of cations the greater the capacity for the storage of plant nutrients