Soils

Question 1

Soil function- hydrological buffer

Answer 1

regulating water, helps control where rain and snowmelt water goes. Water dissolved solutes flow over land or into soil

Question 2

Soil function- food, biodiversity and habitat

Answer 2

the diversity and productivity of living things on soil

Question 3

Soil function- nutrient cycling

Answer 3

cycling nutrients, carbon, nitrogen and many other nutrients stored

Question 4

Soil function- filtering and buffering

Answer 4

Minerals/microbes are responsible for filtering, buffering and detoxing organic/inorganic materials including industrial by products

Question 5

Soil function- physical stability and support

Answer 5

Soil structure provides a medium for plants/rocks

Question 6

Zonal soil

Answer 6

Take hundreds of years to form and consist of weathered rock, organic material, water and air. A soil which has experienced max effect max effect of the climate+natural vegetation upon the parent rock assuming there are no extremes of weathering relief or damage

Question 7

Horizons

Answer 7

(layers) that are distinguishable from the initial material as a result of additions, losses, transfers

Question 8

Soil

Answer 8

Soil is made up of a mixture of soils e.g. organic matter, liquids and gases that occur on the land surface.

Question 9

Humus (O)

Answer 9

It is a thin layer of rotting vegetation- such as grass and leaves. The nutrients in it return to the soil

Question 10

Topsoil (A)

Answer 10

This layer is rich in humus, and the minerals from the rock- so good for growing crops

Question 11

Subsoil (B)

Answer 11

It has little humus but it is rich in minerals and tree roots reach this layer

Question 12

Rock being weathered (C)

Answer 12

It has been broken down into chunks and there is little sign of life

Question 13

Bedrock (D)

Answer 13

Solid rock, not yet weathered but will one day

Question 14

Water erosion- river bank erosion

Answer 14

Soil washed away by unmanaged rivers as they meander floodplains

Question 15

Water erosion- gully erosion

Answer 15

If rills are unattended to grow into gullies affected land cant be used for growing crops- hazard for machinery

Question 16

Water erosion- rill erosion

Answer 16

they are short-lived streams water can gather on surface/run downhill forming channels of water

Question 17

Water erosion- sheet erosion

Answer 17

Overflow can transport topsoil in a uniform fashion

Question 18

Wind erosion- saltation

Answer 18

Main process of soil transportation suspended particles are lifted by wind then fall back to ground so they bounce/hop along surface

Question 19

Wind erosion- creep

Answer 19

Movement occurs when particles are usually top heavy to be lifted by wind

Question 20

Wind erosion- suspension

Answer 20

Small particles that have been lifted into the air remain suspended as dust and taken away

Question 21

Wind erosion- abrasion/attrition

Answer 21

Suspended particles cause abrasion of soil surface when fall back to ground. Also hit into other particles and break away

Question 22

Repeated erosion reduces fertility of soil by:

Answer 22

Removal of topsoil
Reduction in depth of soil
Reducing infiltration
This leads to loss of seeds, fertilisers and pesticides and increased difficulty of field operations

Question 23

Impacts of soil erosion- damage to environment

Answer 23

Leads to deposition of sediment onto roads and neighbouring lands, damage to qual of water resources and sediment in rivers damaging spawning grounds

Question 24

Wind erosion control measures:

Answer 24

Increasing soil cohesion by applying organic matter to soil, increasing roughness of soil surface and increasing plant cover so that surface wind spread will be cut

Question 25

Salinization

Answer 25

It is a build up of salts in soil, eventually leading to toxic levels for plants. Rainwater also contains some salts ad evap of this water from the dry surface leaves the salts behind. Likely to become a prob on soils where the groundwater is within 3m or less of surface- in such cases water rises to surface by capillary action rather than percolating down through soil profile. Affected farmland of this prob globally is up to 20%

Question 26

Granular and crumb structures

Answer 26

Individual particles of sand, silt and clay grouped together in small nearly spherical grains. Water circulates very easily through this soil and found in topsoil profile

Question 27

Blocky structures

Answer 27

Soil particles that sling together in nearly square blocks. Relatively large blocks indicates that the soil resists penetration and movement of water. Commonly found in lower parts of soil where clay has accumulated

Question 28

Prismatic and columnar structures

Answer 28

Soil particles which have formed into vertical columns or pillars separated by vertical cracks. Water circulates with great difficulty.

Question 29

Platy structures

Answer 29

Made up of soil particles aggregated in thin plates or sheets piled horizontally on one another. Plates often overlap, greatly impairing water circulation. Commonly found in forests and high latitude soils.

Question 30

Gleying

Answer 30

Process of soil formation when conditions are waterlogged. Pore spaces is filled with water and become de-oxygenised

Question 31

Solutions to soil erosion

Answer 31

Fertilizers- increase nutrients and organic encourage soil organisms and improve retention.
Afforestation- stabilises the soil and organic matter is returned through leaf litter
Farming practices- crop rotation replenishes nutrients, replacing hedge grows to reduce wind erosion, ploughing across slopes to prevent gullying and having controlled grazing

Question 32

Soil structure

Answer 32

Manner in which individual particles aggregate together, called peds. The shape and alignment determine the pore spaces which water, air and roots penetrate

Question 33

Soil degradation is caused by:

Answer 33

over- cultivation and compaction which reduces the infiltration and water flows as surface run off leading to erosion

Question 34

Latosol- Tropical climate

Answer 34

Acidic and infertile. Found in hot/wet areas and the climate zone is humid without seasons. There is nutrient rich material but once vegetation is removed this deteriorates. There is a rapid nutrient cycle and is high in biodiversity, so if the forest is cleared and the humus is removed nutrients are lost through leaching or soil erosion. These areas get cleared for logging, settlements and crops

Question 35

Podsol

Answer 35

Subarctic areas such as N.A/Europe between tundra and grasslands. Harsh winters and cool summers restrict growth. Poor nutrient cycle and acid humus due to the pine needles being low in nutrients. clear difference between horizons . Coniferous trees can shelter the soil- water can infiltrate and percolate. Human uses include sheep farming and logging.