topic 5 - soil

Question 1

what are layers of soil called?

Answer 1

horizons

Question 2

what are the layers in order?

Answer 2

organic
surface layer
subsoil
substratum
bedrock

Question 3

what features will change depending on which parent rock its made out of?

Answer 3

Depth
Texture
Drainage
Quality
Colour

Question 4

soil forms by interactions of?

Answer 4

• lithosphere
• atmosphere
• hydrosphere
• biosphere

Question 4

what can soil not be formed with out?

Answer 4

• lithosphere
• atmosphere
• hydrosphere
• biosphere
  too much or little of one causes soil erosion

Question 5

what is typical soil made up of?

Answer 5

50-60% mineral particles
1-5% organic matter forms humus when breaks down
40% pore spaces

Question 6

what is precipitation effectiveness?

Answer 6

the balance between precipitation and evapotranspiration (water coming into soil through transpiration then lost bc of evaporation, the loss of water through soil pores)

Question 7

what is a pedalfer?

Answer 7

soil that absorbs water from precipitation

Question 8

what is a pedocal?

Answer 8

looses water

Question 9

what are inputs into soil formation?

Answer 9

○ Organic material
○ Excretions
○ Precipitation
○ Solid particles and gases from atmosphere
○ Gases from respiration of plant roots
○ Mineral breakdown from parent rock

Question 10

what are outputs in soil formation?

Answer 10

Nutrients taken up by plants
Nutrient leaching (flow of nutrients through rainfall
Soil erosion and mass movement (soil creep)
Evaporation
Heat

Question 11

what are transformations?

Answer 11

change of state of matter or energy

Question 12

what are the transformations in soil formation?

Answer 12

Decomposition
Weathering
Nutrient cycling

Question 13

What are transfers in soil formation?

Answer 13

Water
Migration of organisms
Movement of biomass through trophic levels

Question 14

whats a transfer?

Answer 14

Transfer is movement of matter or energy without a change of state

Question 15

why has malnutrition decreased?

Answer 15

• education
• technology
• infrastructure (esp for agriculture)
• political reasons

Question 16

what is food security?

Answer 16

being able to support the population with a stable food source

Question 17

food availability?

Answer 17

sufficient food available on a consistent basis

Question 18

food use?

Answer 18

appropriate use of food based on knowledge of nutrition?

Question 19

what are the haves?

Answer 19

consist of countries that have enough cropland to feed their populations

Question 20

what are the rich have-nots?

Answer 20

do not have sufficient cropland, however, can afford to import food to meet the deficient

Question 21

what are the poor have-nots?

Answer 21

over 3 billion people live in these developing nations, which cannot produce enough food or purchase food for import

Question 22

what is alpine transhumance farming?

Answer 22

○ Moving the cows around according to the different
○ Mobile land stock farming, based on seasonal movements
○ Predictable movements
○ Happens in Switzerland

Question 23

what is slash-and-burn agriculture?

Answer 23

○ Forests are burned and cleared for planting
○ The ash provides some fertilization and it becomes relatively free of weeds
○ This is used for smallholder farmers in peru
Not sustainable after a few years then the land gets overrun with weeds

Question 24

what effects the sustainability of a food system?

Answer 24

Industrialization
Scale
Seed, crop, and livestock choices
Water use
Fertilizers (organic/artificial)
- Intense nutrition form of minerals
-Easily drained and washed into rivers
- Eutrophication
- Oxygen depletion lowers biodiversity
Pest control (biological or chemical)
- Run off into lakes and rivers, killing small
- Bioaccumulation - build up in tissue of organisms
- Biomagnification - build up through trophic levels
Pollinators (relates to location and disease)
Antibiotics
Legislation

Question 25

what are features of sandy soil?

Answer 25

drought sensitive
easily leeched
nutrient and mineral content is low
large air spaces and super porous

Question 26

what are features of loam soil?

Answer 26

• Mixture of clay, sand, silt that avoid the extremes
• Fertile, well drained and easily worked
• Right particle size
• Good porosity

Question 27

what are features of clay soil?

Answer 27

• Very sticky
• Not porous at all
• Deficient in phosphates
• High in potash (organic material)
• Mineral rich
• Very wet, it cant move through clay easily

Question 28

where is soil degredation happening?

Answer 28

globally

Question 29

what are the impacts of soil degredation?

Answer 29

• Reductions on upper horizons of soil have major impact on crop yield pollution and flooding
• Top soil is being degraded much faster than it can be renewed as it takes ages for it to degrade

Question 30

what are causes of soil degredation?

Answer 30

• Deforestation - clearing of land, mining, timber harvesting
  
  • Urbanisation - there is less land covered because of human settlements, there is less land to provide ecosystem services
  • Over-cultivation - of marginal arid lands, had led to desertification
    
    • Agriculture management - irrigation practices, overgrazing, monoculture

Question 31

what counts as chemical degradation?

Answer 31

acid rain
accumulation of salts
soil toxicity

Question 32

what counts as physical degradation?

Answer 32

rainfall intensity
soil erosion
slope gradient
lack of vegetation

Question 33

what counts as biological degradation?

Answer 33

loss of plants and microbial biomes