5.1 Soil

Question 1

soil

Answer 1

mixture of mineral particles and organic material that covers the land, and in which terrestrial plants grow

Question 2

systems approach

Answer 2

approach that explores connections and interdependencies between the parts of a system, and between the parts and the whole

Question 3

soil permeability

Answer 3

the rate at which water and air move from upper to lower soil layers

Question 4

pores

Answer 4

empty spaces or voids in soil that hold air and water, allowing for root penetration and facilitating the exchange of gases and nutrients

Question 5

aeration

Answer 5

transfer involving the movement of air in, out and through soil

Question 6

horizon

Answer 6

• a layer of soil
• O Horizon = top layer of soil in a soil profile that contains organic matter (humus)

Question 7

soil profile

Answer 7

a vertical section through a soil, from the surface down to the parent material, revealing the soil layers or horizons

Question 8

parent material

Answer 8

• underlying geographical material from which soil is formed through weather and other processes
• often formed from bedrock

Question 9

weathering

Answer 9

• the breakdown of rock by the environment
• usually by wind and rain

Question 10

erosion

Answer 10

• the breakdown of rock could
• could be due to weathering or chemicals, animals or humans

Question 11

irrigation

Answer 11

the agricultural technique of adding water to help plant. growth

Question 12

leaching

Answer 12

the dissolving and removing of soil minerals as water moves through the soil

Question 13

salinisation

Answer 13

the accumulation of toxic, water soluble salts in the soil

Question 13

infiltration

Answer 13

a transfer of water as it enters and is absorbed by the soil

Question 14

percolation

Answer 14

a transfer of water through the soil into the bedrock

Question 15

decomposition

Answer 15

a transformation process where dead organic substances are broken down into carbon dioxide and water

Question 16

decomposers (5.1)

Answer 16

heterotrophs that can be animals, bacteria, fungi

Question 17

detritivore (5.1)

Answer 17

• an animal that feeds on dead organic matter using internal digestion
• e.g worms

Question 18

saprotrophs (5.1)

Answer 18

• an organism that feeds on dead organic matter using external digestion
• e.g snails and fungi

Question 19

humus

Answer 19

non-living organic matter in the soil

Question 20

loam

Answer 20

soil that has an even ratio of sand, silt, and clay and is vey fertile

Question 21

seed bank

Answer 21

the reservoir of viable seeds present in soil, which can germinate and grown when conditions are suitable