Biosphere - Soils

Question 1

What is soil made of? + percentages

Answer 1

Minerals - 45%
Air and water - 50%
Organic matter - 5%

Question 2

Leaching

Answer 2

Removal of soluble minerals, salts and humus,which are washed downwards through the soil and may accumulate in the subsoil.

Question 3

Humification

Answer 3

Breakdown or decomposition of plant remains leading to the formation of different types of humus.

Question 4

Illuviation

Answer 4

Introduction of material to a soil layer.

Question 5

Eluviation

Answer 5

Removal of materials from a soil layer.

Question 6

Soil horizon

Answer 6

A layer of soil parallel to the soil crust whose characteristics differ from the horizons above and below.

Question 7

Soil profile

Answer 7

A vertical cross section of a soil, divided into a number of distinct layers, referred to as horizons.

Question 8

Regolith

Answer 8

Fragments of rock

Question 9

Capillary action

Answer 9

Process whereby water and minerals in a solution can be drawn upwards when the rate of evapotranspiration is greater than precipitation.

Question 10

Parent material

Answer 10

Underlying geological material (bedrock) in which soil horizons for,.

Question 11

anerobic conditions occur in…

Answer 11

gley soil

Question 12

Intrazonal soils

Answer 12

Soils that do not reflect climactic or vegetation standard influence.

Question 13

Azonal soil

Answer 13

Immature soils that lack the development of a B horizon

Question 14

What are the 6 factors affecting soil formation

Answer 14

1. Parent material
2. Biotic factors
3. Climate
4. Man
5. Relief
6. Time

Question 15

What is in the O horizon

Answer 15

Leaf litter and humus layer

Question 16

What is in the A horizon

Answer 16

Mix of organic and parent material

Question 17

What is in the B horizon

Answer 17

Mix of mostly parent material with washed in organic matter

Question 18

Podzolisation

Answer 18

Leaching of material of iron, aluminium and humus from the surface layers to the lower layers. Causes A horizon to become grey colour and courser in texture. B horizon becomes darker and has a finer texture with an iron pan.

Question 19

Podzol

Answer 19

Surface - Coniferous vegetation
O horizon - Thin black humus
A horizon - Ash grey colour as minerals are eluviated into B horizon
B horizon - Dark brown - lighter brown
C horizon - Parent material
Distinct layers - not as much biotic activity bc cold + wet climate + acidic

Question 20

Gley

Answer 20

Surface - Grasses and shrubs
O horizon - Partial decomposition
A horizon - Black with acid humus
B horizon - Blue/ grey clayey mud. Waterlogged, slow decomposition. Angular rock fragments. Unstratified.
C horizon - Permafrost. Solid bedrock, generally shallow soil

Question 21

Brown earth

Answer 21

Surface - Deciduous vegetation (roots go straight down)
O horizon - Dark brown
A horizon - Light brown
Iron pan between
B horizon - Gradual leaching, iron and aluminium oxides deposited
C horizon - Parent material