5.3: Soil Degradation and Conservation Flashcards
1
Q
State 3 properties of fertile soils
A
- Made of organic matter that has:
- sufficient soil moisture holding capacity
- good soil structure (to provide drainage and prevent water-logging)
- The presence of a healthy soil community that breaks down organic matter and returns nutrients back into the soil
- Essential nutrients and minerals
- A suitable pH (If the soil is too acidic it will release aluminum ions that are toxic)
2
Q
Why is soil considered a non-renewable resource (if soil can technically be replenished)
A
- slow rate of soil formation (igual que fossil fuels)
- around 1,000 years to develop up to 5cm of soil
- Soil is considered to be a non-renewable resource because it is not replaceable within a human lifespan or at a pace faster than that at which it is used
3
Q
State some natural processes that are threats to soil
A
- Wind erosion
- Chemical degradation
- Physical degradation
4
Q
State some human activities that are threats to soil
A
- urbanisation
- livestock overgrazing
- Deforestation
- Farming (specifically: tillage farming, monoculture –> since it extracts same nutrients leaves soil dry asf, when farming uses excessive irrigation and pesticides)
5
Q
Methods to conserve soil, reducing ________ erosion.
A
Water or wind
6
Q
How do you reduce salinisation
A
- avoid over watering (drip-irrigation?)
- good drainage
7
Q
How do you reduce wind erosion
A
- Adding trees to break up the wind
- Conservation tillage breaks up wind erosion as well due to crop residue
8
Q
How to reduce water erosion
A
controlling run-off through:
- terracing technique (incas)
- furrow diking (lo de que haces
9
Q
How do you manage soil nutrient levels
A
- Addition of synthetic fertilizers.
- crop rotation to mantain soil fertility
