IB DP Environmental Systems & Societies — Topic 5: Land
Agriculture & Food Systems
Subtopic 5.2 — New Syllabus (First Assessment 2026)
Standard Level + Higher Level
12 SL Points
5.2.1 – 5.2.12
8 HL Extensions
5.2.13 – 5.2.20
Overview
What You Need to Know
This subtopic covers global food production systems, land scarcity, food equity, traditional farming vs Green Revolution monoculture, soil conservation techniques, trophic efficiency, food security, and — at HL — regenerative farming, high-tech vertical agriculture, and malnutrition.
A. Global Food System & Equity
Land scarcity, food waste (~30%), food distribution equity, Maasai land rights
Land scarcity, food waste (~30%), food distribution equity, Maasai land rights
B. Farming Systems & Conservation
Green Revolution, synthetic fertilizers, 6 soil conservation techniques
Green Revolution, synthetic fertilizers, 6 soil conservation techniques
C. Regenerative & High-Tech (HL)
Permaculture, zero tillage, vertical farming, diet sustainability, malnutrition
Permaculture, zero tillage, vertical farming, diet sustainability, malnutrition
Guiding Question
- To what extent can the production of food be considered sustainable?
Time allocation: minimum 6 hours SL + additional HL hours. Second subtopic in Topic 5: Land.
5.2.1 – 5.2.3
Land Scarcity, Equity & Food Distribution
Key UnderstandingArable land is a finite resource. Global agriculture produces enough food to feed 8+ billion people, but distribution is inequitable and ~30% is wasted.
🗑️ Global Food Waste (~30%)
Developing nations lose food post-harvest due to storage & transport gaps; MEDCs waste food at retail and consumer levels.
⚖️ Inequitable Access
Marginalized groups (such as indigenous pastoralists) are disproportionately displaced by commercial land-use decisions without input.
Case Study: Maasai Pastoralist Dispossession (East Africa)
Traditional Maasai grazing lands have been increasingly converted to commercial agriculture, national parks, and safari tourism, restricting their seasonal nomadic mobility and creating localized food insecurity.
5.2.4 – 5.2.6
Agricultural Systems & Traditional Practices
Key UnderstandingFarming systems vary widely based on soil, climate, and culture. Traditional practices like nomadic pastoralism and slash-and-burn sustain low-density populations.
| Farming System | Input & Energy Intensity | Outputs & Sustainability |
|---|---|---|
| Subsistence Farming | Low inputs (family labor, manure, saved seed) | Local family food supply; high ecological sustainability at low density |
| Nomadic Pastoralism | Low inputs (seasonal livestock herding) | Meat, milk, blood; sustainable in arid grasslands with low population |
| Slash-and-Burn (Shifting) | Low inputs (forest clearance & burning) | Ash-fertilized crops for 2-3 yrs; forest regenerates if fallow period is long |
| Commercial Monoculture | High inputs (fossil fuels, synthetic NPK, pesticides, hybrid seeds) | High single-crop yield for market; high risk of soil degradation & pollution |
5.2.7
The Green Revolution
Key UnderstandingThe Green Revolution doubled food yields through high-yielding crop varieties (HYVs), synthetic fertilizers, pesticides, and expansion of irrigation.
✅ Benefits
- Saved millions from acute famine in India, Mexico, and Southeast Asia
- Dramatically increased crop yield per hectare without expanding land area
- Lowered global grain market prices
⚠️ Environmental & Social Costs
- Heavy soil degradation, salinization, and chemical runoff eutrophication
- High fossil fuel dependency & groundwater depletion
- Smallholder farmer debt traps due to expensive patented seeds & inputs
5.2.8 & 5.2.9
Synthetic Fertilizers & 6 Soil Conservation Techniques
Key UnderstandingSynthetic fertilizers boost yields at the expense of soil health. Sustainable agriculture utilizes specific soil conservation techniques to preserve topsoil.
| Technique | Mechanism & How It Works | Key Environmental Benefit |
|---|---|---|
| Terracing | Carving step-like flat benches into steep hillsides | Prevents severe water runoff and soil washing downhill |
| Contour Plowing | Plowing furrows horizontally across land contours | Slows surface runoff water speed, trapping sediment |
| Cover Cropping | Planting clover or rye between main harvest seasons | Protects bare topsoil from wind/water erosion; adds organic matter |
| Crop Rotation | Alternating grain crops with nitrogen-fixing legumes | Breaks pest cycles and naturally replenishes soil nitrates |
| Shelterbelts / Windbreaks | Planting rows of tall trees along field borders | Deflects wind, preventing topsoil wind erosion |
| Zero Tillage (No-Till) | Seeding directly into unplowed crop residue | Preserves soil structure, earthworms, and soil carbon storage |
5.2.10
Trophic Efficiency & Diet Sustainability
Key UnderstandingDiets lower in trophic levels (plant-based) are significantly more energy-efficient and sustainable due to ~90% energy loss between trophic levels.
Virtual Water & Land Footprint per kg Food
- 1 kg Beef: ~15,400 Liters of water + 10-20× more land than grains (Trophic Level 3/4)
- 1 kg Pork / Chicken: ~4,300 - 6,000 Liters of water
- 1 kg Wheat / Cereals: ~1,500 Liters of water (Trophic Level 1 - Producer)
- 1 kg Vegetables / Potatoes: ~290 - 400 Liters of water
Energy Loss Rule: Eating grain directly feeds 10× more people than feeding the grain to cattle and consuming the beef.
5.2.11 & 5.2.12
Sustainable Supply & The 4 Pillars of Food Security
Key UnderstandingFood security exists when all people have physical and economic access to safe, nutritious food. Requires sustainable intensification without expanding farmland.
| Pillar of Food Security | Focus & Definition |
|---|---|
| 1. Availability | Sufficient global/local food production supply |
| 2. Access | Economic affordability and physical access to market supplies |
| 3. Utilization | Nutritional quality, clean water, and sanitation for proper absorption |
| 4. Stability | Consistent food access over time without climate or conflict disruptions |
HL — 5.2.14 & 5.2.15
Regenerative Agriculture & PermacultureHL
Key UnderstandingAlternative systems like permaculture, regenerative farming, and mob grazing restore soil health, sequester carbon, and boost biodiversity.
🌿 Permaculture Principles
Design agricultural systems modeled on natural ecosystems: polycultures, closed nutrient loops, rainwater harvesting, zero chemical inputs.
🐂 Regenerative Mob Grazing
Concentrating livestock in small paddocks for short periods mimics wild herds, trampling organic matter into soil and building topsoil carbon.
HL — 5.2.16
High-Tech & Vertical AgricultureHL
Key UnderstandingModern indoor high-tech greenhouses, hydroponics, and urban vertical farms achieve extreme productivity per m² with minimal water use.
| Technology | Mechanism & Advantages | Key Trade-offs |
|---|---|---|
| Vertical Farming | Stacked indoor layers using LED lighting & hydroponics; 90% less water, zero soil erosion, urban proximity | High energy consumption for lights/climate control; high capital startup cost |
| Precision AI Farming | Drones, sensors, and GPS targeting water & fertilizers to exact plant needs | Reduces chemical waste; expensive digital infrastructure required |
HL — 5.2.17 – 5.2.20
Diet Sustainability, Wild Harvest & MalnutritionHL
Key UnderstandingDietary footprint varies widely. Malnutrition encompasses both undernourishment (hunger) and overnourishment (obesity).
⚠️ Undernourishment (~735M)
Chronic caloric deficit causing stunting & wasting in impoverished, climate-shocked, or war-torn regions.
🍔 Overnourishment (~1.9B)
Excess caloric intake from cheap, ultra-processed, energy-dense foods leading to obesity and cardiovascular diseases.
EAT-Lancet Planetary Health Diet: Recommends 50% reduction in global red meat and sugar consumption, doubling fruit, vegetable, legume, and nut intake.
Key Terms Glossary
Essential Vocabulary
| Term | Definition |
|---|---|
| Arable Land | Land suitable for growing agricultural crops |
| Green Revolution | 1950s-70s agricultural shift to high-yielding seeds, synthetic fertilizers, pesticides, and heavy irrigation |
| Subsistence Farming | Agriculture practiced to provide food for the farmer's family with minimal market surplus |
| Contour Plowing | Plowing across sloping land along elevation contour lines to reduce water runoff erosion |
| Zero Tillage (No-Till) | Planting seeds directly into undisturbed crop residue without plowing |
| Food Security | Condition where all people have physical and economic access to safe, nutritious food |
| Permaculture | Ethical agricultural design system mimicking natural self-sustaining ecosystems |
| Vertical Farming | Indoor urban farming growing crops in vertically stacked layers using hydroponics and LEDs |
| Malnutrition | Deficiencies, excesses, or imbalances in a person's intake of energy and/or nutrients |
Exam Preparation
Key Takeaways & Exam Tips
Must-Know Concepts
- Food Equity: Global agriculture produces enough food; starvation stems from poor distribution, poverty, and 30% food waste.
- Green Revolution Trade-off: High crop yields vs soil salinization, chemical runoff, and farmer debt.
- 6 Soil Conservation Methods: Terracing, Contour Plowing, Cover Cropping, Crop Rotation, Shelterbelts, Zero Tillage.
- Trophic Energy: Eating plant-based foods directly saves 90% energy compared to livestock consumption.
- HL Malnutrition Spectrum: Contrast undernourishment (hunger) with overnourishment (obesity).
Exam tip: When comparing commercial monoculture to permaculture in 9-mark essay questions, evaluate inputs (fossil fuels vs labor), outputs (single commodity vs diverse food), and long-term soil sustainability.
You've covered all 20 syllabus points ✅
5.2.1 – 5.2.12 (SL) + 5.2.13 – 5.2.20 (HL) · Complete Topic 5: Land!