Flashcards · 0680 · Topic 2

Land flashcards

14 cards on Topic 2, subtopics 2.1 to 2.3. Pick a subtopic or study them all.

Study mode needs JavaScript. Every card is listed below, so you can still cover the answers and test yourself.

All 14 cards

For a quick read-through or printing. Cover the right-hand side to test yourself.

What is soil made of?: Mineral particles (sand, silt and clay), organic content, air (gases) and water.
Why is loam an ideal soil for crops?: It has a good mix of particle sizes and pore spaces, holds moisture yet drains well, contains useful organic and mineral content, and is easy to cultivate.
Which mineral ions do plants need from soil, and what for?: Nitrate (N) for growth of leaves and proteins, phosphate (P) for root growth, and potassium (K) for flowers, fruit and resistance to disease.
Sandy soil vs clay soil: Sandy: large particles and pore spaces; drains quickly and is easy to dig, but dries out and loses nutrients. Clay: tiny particles; holds water and nutrients, but drains poorly, can waterlog and is hard to work.
Which conditions allow optimum crop growth?: A long enough growing season, suitable weather (temperature and water) and enough daylight hours for photosynthesis, along with soil nutrients and the right pH.

Subsistence vs commercial agriculture: Subsistence: food grown mainly for the farmer’s own family. Commercial: crops or livestock produced for sale at a profit.
What is sustainable food production?: Producing enough food for the present generation using methods that allow future generations to keep growing food on the same land.
Name ways of increasing crop yield: Crop rotation and intercropping, improved irrigation such as drip irrigation, mechanisation, fertilisers, pest control, genetically modified crops, greenhouses and hydroponics, and agroforestry.
Drip irrigation vs flood irrigation: Drip: delivers water directly to roots with little waste, so it is sustainable. Flood: wastes water and can cause waterlogging and salinisation over time.
What problems can unsustainable farming cause?: Soil erosion, salinisation, nutrient exhaustion, pollution from overuse of fertiliser and pesticide, deforestation, biodiversity loss from monoculture, and food shortages when cash or biofuel crops replace food crops.

What causes soil erosion?: Unsustainable farming such as overgrazing, deforestation, farming on steep slopes, leaving soil bare, and removal of soil by wind and water.
What are the impacts of soil erosion?: Lower crop yields, silting of rivers, desertification, landslides and mudslides, loss of habitat, malnutrition and famine, and displacement of people.
How do terracing and contour ploughing reduce erosion?: Terracing cuts steep slopes into flat steps; contour ploughing makes furrows along the slope rather than down it. Both slow surface run-off so water soaks in instead of washing soil away.
How do wind breaks and vegetation cover reduce erosion?: Wind breaks (lines of trees or hedges) slow the wind across fields. Keeping plant cover means roots bind the soil and leaves shelter it from rain.