5.1 Soil

Question 1

What does soil do?

Answer 1

Provide the foundation of terrestrial ecosystem as a medium for plant growth. Contribute to biodiversity by providing a habitat and a niche for many species.

Question 2

Inputs and outputs of soil?

Answer 2

Inputs:
- water from rivers and streams
- minerals such as phosphorus, nitrogen and potassium.

Output:
- water and mineral absorbed by plant root in plant uptake.
- water evaporates from the soil into the atmosphere.

Question 3

Importance of outputs?

Answer 3

Air/gases play a vital role in processes such as photosynthesis and climate regulation. Water and mineral are vital for plant growth and transferring these elements into the biosphere.

Question 4

What are anthropogenic inputs?

Answer 4

Fertilisers can lead to soil acidification, microbial distribution, nutrient imbalance and structural degradation.

Question 5

How flows impact soil health?

Answer 5

Erosion: water transfers soil particles, which leads to loss of topsoil which contains most oxygen, organic matter and microorganisms.

Question 6

Pedosphere is for?

Answer 6

Soil

Question 7

What is soil made up of?

Answer 7

Soil is made up of inorganic and organic components, water and air. Develop stable, layered structure known as a profile made up of several horizons produced by interacting within systems over long period of times.

Question 8

What are the percentages that make up soil?

Answer 8

45% - minerals
5% - organic matter
25% - water
25% - air

Question 9

What are the different layers of soil?

Answer 9

Organic layer, topsoil, subsoil

Question 10

Why does soil texture change?

Answer 10

Water supply, cultivation practices, soil type affect the composition, climate organisms, topgraphy.

Question 11

How does climate affect soil?

Answer 11

High rainfall in tropical climates leads to significant water erosion and leaching of nutrients. Uk is more sandy, loamy and clay based soils as it is cooler, wetter climates.

Question 12

How soil is formed and the roles each layer has?

Answer 12

The organic layer containing leaf litter and dead organisms that have not completely decomposed to form soil. Contains humus which is dark, nutrient rich product of decomposition.

The next is mixed layer also called topsoil. Contains higher percentages of clay soil particles and minerals which have deposited in the B horizon through soil flows such as leaching.

C horizon is the layer of parent rock, broken into smaller pieces by weathering.

Question 13

What does humus do?

Answer 13

Humus contributes to the texture of the soils. Dark brown or black substance beneath the leaf litter. Crumbly texture formed by the partial decay of dead plants. Influences nutrient.

Question 14

What are loam soils and why are they the most productive soils?

Answer 14

Loam is balanced mix of sand, silt and clay, offering optimal drainage, moisture retention and fertility.