Land degradation and population growth

Overview

Intensive farming, monoculture, fertiliser, hedgerow loss, overgrazing, desertification and irrigation, and how population growth and urbanisation affect food security.

What you need to know

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Questions from this subtopic

Each one with the model answer underneath.

1. 1

   Define land degradation.

   Model answer

   Land degradation is a lasting decline in the ability of land to grow crops or support ecosystems. Soil erosion, nutrient loss and desertification are all forms of it.

2. 2

   What is intensive farming?

   Model answer

   Intensive farming aims for the highest possible output from a given area of land. The system relies on heavy use of fertilisers, pesticides, machinery and irrigation.

3. 3

   Explain how monoculture contributes to land degradation.

   Model answer

   Monoculture grows the same crop on the same land year after year. The soil loses the same nutrients each season, and pests and diseases build up.

4. 4

   How can heavy farm machinery degrade farmland?

   Model answer

   Heavy machinery compacts the soil, squeezing out the air spaces that roots and water need. Compacted soil drains poorly, so rain runs off and erodes the surface.

5. 5

   Explain how over-reliance on artificial fertiliser can harm soil over time.

   Model answer

   Artificial fertiliser supplies nitrogen, phosphorus and potassium but adds no organic matter. Soil organic matter declines, so the soil holds less water and supports fewer soil organisms.

6. 6

   Why does removing hedgerows increase soil erosion?

   Model answer

   Hedgerows act as windbreaks and slow rainwater running across fields. Large open fields without them lose topsoil to wind and water.

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