Strategies to Increase Food Supply
Irrigation, Aeroponics/Hydroponics, Biotechnology (GM), Green Revolution & Appropriate Technology
8 → 10bn
Population by 2050
↑ Demand
Changing diets (more meat)
828M
Undernourished people
Sustainable
Not just more land
Simply expanding farmland = deforestation. We need strategies that produce MORE food from EXISTING land sustainably.
Irrigation is the artificial watering of crops, allowing farming in areas with unreliable rainfall and increasing yields dramatically. In 1998, just 20% of farmland was irrigated but produced 40% of global crops.
Efficiency Metrics
Setup Cost
Low
Running Cost
Low
Advantages
- ✓Simple to implement
- ✓Good for rice paddies
- ✓Low technology needed
Disadvantages
- ✗50%+ water evaporates
- ✗Causes waterlogging
- ✗Salt accumulation (salinization)
Example
Rice paddies across Asia
1998: 20% of farmland was irrigated but produced
40% of global crops
Doubling water = 7x yield increase for cereals
Large-Scale Example: Aswan High Dam, Egypt
Controls the Nile, irrigates the entire Nile Valley year-round, provides hydroelectric power. BUT: Cost billions, displaced communities, disrupted river ecosystems, and trapped sediment that previously fertilized fields.
Hydroponics
Plants grown in nutrient-rich water (roots submerged). Used in greenhouses and vertical farms.
Aeroponics
Plants suspended, roots misted with nutrient solution. Even more efficient than hydroponics.
Traditional Field Farming
Vertical Farm (Hydroponics)
Case Study: Almeria, Spain "Sea of Plastic"
40,000 ha
Greenhouses
40-50%
Europe's fruit/veg
Year-round
Production
Plastic waste
Environmental cost
GM crops have genes altered to improve characteristics: drought-resistance, pest-resistance, higher yields, or better nutrition. Controversial but widely adopted in NEEs/LICs.
Click factors to add them to the scale and form your judgment
Balanced - context matters
Benefits (click to add)
Risks (click to add)
Golden Rice
Vitamin A fortified
Bt Cotton
Pest-resistant
Drought Maize
Water-efficient
HY Wheat
50%+ more grain
The GM Debate
HICs (Europe): Ban/restrict GM - "Frankenstein foods" concerns, precautionary principle.
NEEs/LICs (India, Brazil, Philippines): Widely adopted - pragmatic view that food security outweighs unproven risks.
The original Green Revolution (1960s-80s) developed high-yield varieties (HYVs) that tripled wheat yields in India and averted predicted famines. BUT: Required expensive fertilizers, pesticides, and irrigation - causing environmental damage and farmer debt.
1960
Early Green Revolution
High-yield varieties (HYVs) of rice and wheat developed
Norman Borlaug develops dwarf wheat varieties that produce 2-3x more grain
Crop Yields (vs 1950)
30%
Environmental Damage
10%
New Green Revolution Example: System of Rice Intensification (SRI)
+50%
Yield increase
-40%
Water use
-30%
Input costs
Millions
Farmers adopted
New Green Revolution: Sustainable Intensification
Increase yields WITHOUT environmental harm. Focus on small farmers, not just agribusiness. Techniques: crop rotation, organic fertilizers, integrated pest management, rainwater harvesting, agroforestry.
Appropriate technology = simple, low-cost, sustainable technology suited to local skills and resources. Empowers smallholder farmers rather than making them dependent on expensive imports or expertise.
Select Farmer Scenario
Ethiopian Farmer's Situation
Budget
$100
Electricity
No
Water
Scarce
Land
1 hectare
Crops
Vegetables
Choose Appropriate Technology
No Single Strategy Solves Food Insecurity
A COMBINATION is needed: irrigation for water security, GM for climate resilience, appropriate technology for affordability, sustainable practices to protect the environment. Different strategies suit different contexts (HIC vs LIC, large vs small farms).
Sustainability is Critical
Environmental damage from over-irrigation, pesticides, and monoculture creates LONG-TERM threats. Short-term yield gains mean nothing if soil is degraded, aquifers depleted, or biodiversity lost. The New Green Revolution prioritizes SUSTAINABLE intensification.
Which irrigation type is most water-efficient?
Evaluate the use of irrigation to increase food supply. Consider both advantages and disadvantages. [6 marks]