Key Idea: Most marks in topic 5.2 come from farming systems and farmers' choices. Then learn soil conservation, diets and strategies for a sustainable food supply.
1. Farming systems (most marks)
- Intensive farming uses many inputs per hectare; extensive uses more land and fewer inputs.
- Commercial farms sell their produce; subsistence farms feed the family.
- Choices depend on soil, climate, culture and money.
2. Soil conservation
- Cover crops and mulch protect bare soil from rain and wind.
- Terraces and contour ploughing slow water on slopes.
- Windbreaks, no-till and crop rotation keep soil in place and fertile.
3. Diets and food supply
- Eating lower in the food chain needs far less land: plants feed more people per hectare than meat.
- Cutting waste, plant-based foods and better nitrogen use make food supply more sustainable.
- Food security means everyone can get enough safe, nutritious food, physically and economically.
How it is examined:
| Question | How to score |
|---|---|
| [1] to [2] Identify an input or output of a farm system | Name it and say what it does. |
| [2] to [4] Outline soil conservation methods | Name the method and how it stops erosion. |
| [3] to [4] Explain why diets differ in their footprint | Trophic levels, land and emissions per kg. |
| [7] Compare two named food production systems | Inputs, outputs, impacts, both named. |
| [9] Discuss strategies for a sustainable food supply | Several strategies, named examples, a judgement. |
Key terms, one line each:
| Term | In one line |
|---|---|
| Intensive farming | high inputs and high yields on a small area |
| Extensive farming | low inputs over a large area |
| Subsistence farming | growing food mainly to feed the family |
| Food security | everyone can get enough safe, nutritious food |
| Crop rotation | growing different crops in turn to keep soil fertile |
Last-minute check: answer, then tap to see.
Intensive or extensive: cattle ranching in Australia? Extensive: few inputs over a huge area.
How do terraces conserve soil? They slow run-off on slopes, so less soil is washed away.
Why does a beef diet need more land? Energy is lost at each trophic level.
What are the two parts of food security? Physical and economic access to food.
IB-style questionEvaluate[4 marks]
Many countries have turned to intensive farming to feed growing populations. Evaluate intensive farming as a way to feed a growing population.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Exam tips
- For a farm system, name its inputs and outputs.
- For soil conservation, say what each method stops: wind, water or nutrient loss.
- In a [9], give several strategies with named examples, then a judgement.
- Use real numbers for diets: land or emissions per kilogram.