Feeding the World

Growing more food

When food supply falls short, countries look for ways to grow more. Large-scale strategies push yields up fast. Irrigation brings water to dry land, aquaculture farms fish, hydroponics grows plants without soil in a nutrient solution, biotechnology improves crops through their genes, and the Green Revolution spread modern seeds and chemicals. Thanet Earth in the UK is a huge greenhouse complex that grows salad crops all year using hydroponics and extra light. Sustainable strategies aim to feed people without harming the land, through permaculture, organic farming, urban farming, and cutting food waste and food miles. An urban farming scheme in Kenya lets local people grow fresh food in the city. This module weighs the big-scale answers against the sustainable ones.

Food strategy words

Learn these before you match any strategy, and notice which ones grow the most and which harm the land least.

Large-scale against sustainable

The two kinds of strategy pull in different directions, which is why they must be weighed rather than simply listed.

How to weigh a strategy

A strong answer never just names a strategy. It judges one against another on three tests. How much extra food does it grow. What does it cost the environment in soil, water or wildlife. And who actually gains, a big company or the local community. Run a large-scale scheme and a local one through the same three tests, then say which suits the place and why the other fits worse.

Match the strategy to what it does

Which strategy is this?

At Thanet Earth, salad crops are grown in vast greenhouses with their roots in a nutrient solution rather than soil, under extra lighting. Which strategy is this?

• Hydroponics.
• Aquaculture.
• Organic farming.
• Simple irrigation of a field.

Sustainable food strategies

Select the TWO strategies that make food supply more sustainable.

• Organic farming that avoids artificial chemicals
• Reducing food miles by growing food locally
• Clearing rainforest to make huge new farms
• Spreading far more chemicals on every field

Yield increase

A hydroponic greenhouse raises the yield of tomatoes from 20 tonnes per hectare to 60 tonnes per hectare. Subtract to find the increase in yield per hectare, in tonnes.

Order how urban farming feeds a city

Put the stages of an urban farming scheme in order, earliest first.

• Unused land is found within the city
• Local people plant crops on the land
• Fresh food grows close to where people live
• Less transport is needed, cutting food miles

Complete the facts

Growing plants without soil in a nutrient solution is called _____. Supplying water to dry land so crops can grow is _____. Food grown in ways that do not harm future supply is _____. Farming that avoids artificial chemicals is _____ farming.

Match the example to its type

Spot the true food strategy facts

Tap the TWO statements that are true about feeding the world.

• Hydroponics grows plants without soil
• Sustainable strategies protect food supply for the future
• Large-scale strategies never have any drawbacks
• Growing food far away always cuts food miles

Choose a strategy

Read each case and choose the best response, with a reason.

• A wealthy country wants to grow large amounts of salad all year in a small space. Which strategy fits best?
• A poorer city wants a cheap, sustainable way for families to get fresh food. Which fits best?
• A student says the large-scale scheme is simply best because it grows the most food. How could the answer be improved?

Weigh the food strategies

Compare a large-scale strategy such as Thanet Earth with a sustainable local scheme such as urban farming in Kenya, and judge which better feeds people.

• Explain how the large-scale strategy increases food supply
• Explain how the sustainable local scheme increases food supply
• Weigh the yield of each against its environmental cost
• Weigh who benefits most from each strategy
• Finish with a judgement on which suits its place best and why