Strategies for increasing food supply. Revision Notes | GCSE AQA Higher Geography

1. Why Increasing Food Supply Matters

The global population is growing, yet the amount of productive farmland is not. Climate change, water scarcity, and soil degradation are squeezing food production at exactly the moment demand is rising. Geographers need to understand the range of strategies available to close this gap — and crucially, their trade-offs.

These strategies range from ancient techniques like irrigation to cutting-edge biotechnology. Some are best suited to wealthy, high-income countries (HICs); others are designed specifically for lower-income countries (LICs) where resources are limited. Knowing which strategy fits which context is a key exam skill.

2. Strategies for Increasing Food Supply

There is no single solution to food insecurity — geographers recognise a toolkit of strategies, each with its own strengths and limitations. The specification requires you to know irrigation, aeroponics, hydroponics, the new green revolution, biotechnology, and appropriate technology.

Irrigation is one of the oldest and most widespread strategies. In arid regions such as parts of North Africa and South Asia, it has transformed desert land into productive farmland. However, over-irrigation can waterlog soil and cause salinisation — a build-up of salt that eventually makes land infertile. This is a critical long-term risk that examiners expect you to flag.

Moving from soil-based farming to soil-free methods opens up new possibilities. Hydroponics grows plants in nutrient-rich water, while aeroponics suspends roots in air and mists them with nutrients. Both methods use significantly less water than conventional farming and can be set up in urban environments, greenhouses, or areas with poor soil quality.

2a. The New Green Revolution and Biotechnology

The original Green Revolution of the 1960s and 1970s introduced high-yielding crop varieties, fertilisers, and pesticides — dramatically increasing food production in countries such as India. The new green revolution builds on this by targeting sub-Saharan Africa and other food-insecure regions, combining improved seed varieties with better farming practices and local knowledge.

Biotechnology takes this further by genetically modifying (GM) crops to be drought-resistant, pest-resistant, or more nutritious. Golden Rice, for example, was engineered to contain Vitamin A, addressing a major nutritional deficiency in parts of Asia. However, GM crops raise concerns about biodiversity loss, the dominance of large corporations over seed supply, and the long-term ecological effects of modified organisms entering natural ecosystems.

2b. Appropriate Technology

Appropriate technology is a strategy specifically designed for communities in LICs where expensive equipment is unaffordable and technical expertise is limited. The idea is that the technology must be maintainable using local skills and resources. A classic example is the treadle pump — a foot-powered water pump that allows smallholder farmers in countries such as Bangladesh to irrigate their crops without electricity or expensive machinery.

Appropriate technology tends to produce lower yields than high-tech alternatives, but it is sustainable in the long term because communities can repair and operate it themselves. This contrasts with high-tech solutions that may break down and cannot be fixed locally, leaving farmers worse off than before.

3. Large-Scale Agricultural Development: The Indus Basin Irrigation System, Pakistan

Now that you have the toolkit of strategies, the specification requires you to apply this understanding to a named large-scale agricultural development — one that has both advantages and disadvantages. The Indus Basin Irrigation System (IBIS) in Pakistan is one of the largest irrigation networks in the world and provides a strong case study for this.

The IBIS uses a vast network of canals fed by the Indus River and its tributaries to irrigate farmland across Pakistan. It supports agriculture across millions of hectares [VERIFY exact figure], making Pakistan one of the world's leading producers of wheat, cotton, and rice. Without this system, much of Pakistan's agricultural heartland would be too dry to farm.

Worked example: How to Structure a Case Study Answer: Advantages and Disadvantages

Assess the advantages and disadvantages of a large-scale agricultural development you have studied. [9 marks]

1. The Indus Basin Irrigation System (IBIS) in Pakistan is one of the world's largest irrigation networks, designed to supply water to farmland in an otherwise arid region. — Always name the development and its location immediately. This signals to the examiner that you have a specific case study, not a generic answer.
2. The IBIS has dramatically increased food production, supporting the cultivation of wheat, cotton, and rice across millions of hectares [VERIFY]. This has improved food security for millions of people and generated significant agricultural export income for Pakistan. — Link the advantage to a real outcome — food security, economic income, or employment. Use [VERIFY] where exact statistics are not confirmed.
3. However, over-irrigation has led to widespread waterlogging and salinisation of soils. It is estimated that a significant proportion of irrigated land in Pakistan has been affected by salinisation [VERIFY], reducing long-term agricultural productivity. — The disadvantage must be specific to the case study, not just a generic problem. Salinisation is a well-documented consequence of the IBIS and directly links to the irrigation strategy taught earlier.
4. The diversion of river water has also reduced water flow to the Indus Delta, damaging mangrove ecosystems and reducing fish stocks — affecting the livelihoods of communities dependent on fishing [VERIFY specific impact]. — Top-band answers include social, economic, and environmental impacts. Adding an environmental consequence shows geographical breadth.
5. Overall, the IBIS has been essential for Pakistan's food security and economy, but its long-term sustainability is threatened by soil degradation and environmental damage. A more sustainable approach would combine irrigation with soil management techniques to prevent salinisation. — The conclusion must weigh advantages against disadvantages and reach a clear overall judgement. This is what separates a Level 3 answer from a Level 2 answer.

Answer: The IBIS has delivered major food security and economic benefits for Pakistan, but long-term soil salinisation and environmental damage to the Indus Delta represent serious disadvantages. Overall, the development has been beneficial in the short term but requires improved management to remain sustainable.

4. Comparing Strategies: Which Works Best?

No single strategy is universally superior — the right approach depends on the context. In HICs with capital investment and technical expertise, aeroponics, hydroponics, and GM biotechnology can deliver high yields with reduced land and water use. In LICs, appropriate technology and the new green revolution are more realistic because they work within existing resource constraints.

Large-scale developments like the IBIS show that even well-resourced strategies carry long-term risks. This is why evaluation — weighing up both advantages and disadvantages — is central to geography exam questions on this topic.

5. Exam Technique: Getting Full Marks on Food Supply Questions

Questions on food supply strategies tend to use command words like 'explain', 'assess', or 'evaluate'. Each demands a different response structure. Getting the command word right is the difference between Level 2 and Level 3 marks.

Bringing this together: the specification asks you to know the range of strategies, understand how they work, and evaluate a large-scale example. Every exam question on this topic — whether it asks you to 'explain', 'assess', or 'evaluate' — is testing whether you can move beyond description and make a geographical judgement backed by specific evidence.