Cambridge O Level Environmental Management: Land — Revision Notes (5014, 2027-2029)

Syllabus edition note. These notes follow the Cambridge O Level Environmental Management 5014 syllabus for exams in 2027, 2028 and 2029. Candidates sitting the November 2026 series in Mauritius use the 2025-2026 syllabus, where farming is covered in Agriculture and the environment.

Topic 2 Land of Cambridge O Level Environmental Management (5014) asks how soil supports crops, how farmers raise yields, what goes wrong when farming is unsustainable, and how soil erosion is caused and prevented. The examiners expect accurate terms (pore spaces, salinisation, eutrophication) and, in “discuss” questions, a balance of benefits and limitations.

Full explanations are in the Land study guide; test yourself with the Land practice questions.

Syllabus coverage (5014, 2027-2029)

Sub-topic	Outcomes	Must know
2.1 Soils and crop growth	2.1.1-2.1.6	Soil composition; why it matters; loam; weather; wet and dry seasons; photosynthesis conditions
2.2 Food production and crop yield	2.2.1-2.2.4	Types of agriculture; sustainable food production; 12 yield strategies; 9 unsustainable impacts
2.3 Soil erosion	2.3.1-2.3.3	Causes; impacts; six prevention strategies

2.1 What is soil made of, and why does it matter?

Four components: mineral particles (sand, silt, clay); organic content (living plants, animals, fungi, bacteria, and decomposed organic matter); gases; water. (Percentages are not required.)

Soil property	Why it matters for crops
Mineral particles	Sand drains fast but holds few nutrients; clay holds water and nutrients but can waterlog
Nutrients	Organic content plus ions: nitrate (NO3-), phosphate (PO4 3-), potassium (K+)
pH	Acidic, neutral or alkaline soils suit different crops
Pore spaces	Hold air and water; let roots grow
Gas content	Roots need oxygen for respiration
Water and drainage	Enough water for growth without waterlogging
Ease of cultivation	Light soils are easier to plough

Loam is the best growing medium because it has an ideal mix of particles and pore spaces, retains moisture, contains organic content and ions, drains excess water, and is easy to cultivate.

Weather = day-to-day conditions of the atmosphere in a location. Some regions have wet and dry seasons that control when crops can grow. Optimum photosynthesis and growth depend on the length of the growing season, optimum weather conditions and daylight hours.

2.2 How is food produced and how can yields rise?

Types of agriculture

• Arable (crops), pastoral (livestock), mixed (both).
• Subsistence (feeds the family) vs commercial (for sale).
• Intensive: high inputs of labour, capital or chemicals per hectare.
• Monoculture: a single crop over a large area.

Sustainable food production = producing enough food for the present generation using methods that ensure future generations can grow food from the same land.

Twelve strategies to raise yield - grouped

Group	Strategies	How they help
Planting patterns	Mixed cropping, intercropping, crop rotation	Different nutrient needs; fewer pests; legumes add nitrogen
Water	Trickle/drip irrigation, rainwater harvesting, automated watering	Water goes to roots with less waste
Machines	Mechanisation	Faster planting and harvesting over large areas
Genetics	GMOs - genes removed, changed or inserted	Pest resistance, drought tolerance, higher yield
Controlled environments	Greenhouses, hydroponics, aeroponics	Control of temperature, water and nutrients all year
Livestock	Managed grazing, livestock rotation	Pasture recovers; less overgrazing
Land use	Urban farming, agroforestry	Food grown in cities; trees shelter crops and add organic matter
Nutrients	Inorganic NPK fertilisers; organic fertilisers (crop residue, manure, mulch)	Replace nitrate, phosphate and potassium
Pests	Insecticides, herbicides, fungicides; biological control	Reduce crop losses

What happens when farming is unsustainable?

1. Overproduction → food wastage.
2. Cash crops (coffee, cotton, soya beans, palm oil) and biofuel crops replace food crops → food shortages.
3. Poor irrigation → soil erosion, salinisation (salt left as water evaporates) and waterlogging.
4. Overuse of pesticides → pest resistance, pest resurgence, harm to pollinators.
5. Overuse of fertilisers → leaching, nutrient enrichment, eutrophication of water.
6. Nutrient exhaustion → soils lose organic content and ions.
7. Removal of vegetation → deforestation, overcultivation, overgrazing.
8. Monoculture and intensification → soil and water pollution, loss of biodiversity.
9. Soil erosion → loss of topsoil and nutrients.

2.3 Why does soil erode and how is it prevented?

Causes: unsustainable farming; deforestation; farming on steep slopes; bare soil; wind and water.

Impacts: silting of rivers; desertification; mass movement (landslides, rockslides, mudslides); loss of habitats and biodiversity; lower crop yields; malnutrition and famine; displacement of people.

Strategy	What it does
Terracing	Flat steps on slopes reduce soil movement and surface run-off
Contour ploughing	Furrows follow the contours, reducing run-off
Bunds	Low banks reduce run-off and wind speed
Wind breaks	Trees or hedges protect crops and reduce wind erosion
Vegetation cover	Roots bind soil; plants absorb water and slow run-off
Organic matter	Improves soil structure so it holds together

Worked example: matching strategy to problem

A farmer on a 20° hillside in a region with heavy wet-season rain loses topsoil every year.

• Problem: water erosion of bare soil on a steep slope.
• Best strategies: terracing (reduces run-off on steep land) and keeping vegetation cover between crops.
• Why not wind breaks? They target wind erosion, which is not the main problem here.

Common mistakes and exam traps

• Saying clay soil is best because it holds water: it waterlogs and is hard to cultivate; loam is best.
• Confusing weather (day to day) with climate (many years).
• Writing “fertiliser causes eutrophication” without the steps of leaching and nutrient enrichment.
• Mixing up intercropping (crops in alternate rows) with crop rotation (changing crops each season).
• Naming a strategy without saying how it reduces erosion.

Frequently asked questions

Why is loam the best soil for crops? It has an ideal mix of sand, silt and clay with pore spaces, so it holds moisture and nutrients but drains excess water and is easy to cultivate.

What is salinisation? A build-up of salts in soil when irrigation water evaporates, which lowers crop yields. The 5014 syllabus lists it as a result of mismanaged irrigation.

Is biological control a pesticide? No. It uses a natural predator or parasite to reduce a pest, while chemical control uses insecticides, herbicides or fungicides.

Official syllabus

Cambridge O Level Environmental Management (5014) syllabus for 2027, 2028 and 2029 - official syllabus PDF, Topic 2 Land.