Soil

Question 1

How is soil formed?
Outline this process

Answer 1

• Pedogenesis
  Parent material is weathered
  Accumulation of mineral grains
  Vegetation enhances weathering
  Fine material enriched in organic matter
  Regeneration or retrogression degeneration

Question 2

What is soil retrogression degeneration?

Answer 2

Soil runs out of minerals

Question 3

What is the function of soil formation?

Answer 3

f(Cl, O, R, P, T, …)
Cl - climate
O - organisms
R - relief
P - parent material
T - time
… - stochastic factors (fire, flood, humans)

Question 4

Is soil renewable or non renewable?

Answer 4

Non renewable

Question 5

What is the total volume of cultivated topsoil to a depth of 0.5m in the UK?

Answer 5

25 Km^3

Question 6

What is ~1/2 of the volume of soil made of?

Answer 6

Pore space containing air or water

Question 7

How much organic matter is there in most arable soils?

Answer 7

Less than 2%

Question 8

What 3 main types of soil are there?

Answer 8

Sandy - Good aeration, water drains quickly, limited water and nutrient storage
Clay - Good water and nutrient storage. Slow draining
Loamy - mixture of sand, silt and clay. Ideal for most plants

Question 9

How many major groups of soil are there?

Answer 9

12, largely relates to biomes, environment and climate