👶 Increasing birth rate
In some countries the population is growing fast. More babies means more mouths to feed, and food production may not keep up.
Food Production » Food Security and Farming Techniques
What you'll learn this session
Study time: 30 minutes
AQA spec: 4.7.5.1, 4.7.5.2 (Biology only)
- What food security means and six biological factors that threaten it
- Why sustainable methods of food production are needed
- How limiting movement, controlling temperature and high protein feed make farming more efficient
- The ethical objections to, and the pros and cons of, intensive farming
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Unlock This CourseWhat is food security?
Millions of people around the world do not get enough to eat. Biologists and farmers work to solve this problem. The key idea is food security.
Key terms:
- Food security: having enough food to feed a population.
A country with good food security can feed everyone who lives there. A country with poor food security cannot. Many things can threaten food security, and you need to be able to describe some of the biological ones.
Factors that threaten food security
These are the factors named in the specification. Learn each one with its reason.
✈ Changing diets
In developed countries, people's diets have changed so that scarce food resources are transported around the world. Food that is scarce has to be moved long distances to meet demand.
🐛 New pests and pathogens
New pests and pathogens that affect farming can destroy crops or make farm animals ill. Less food is produced.
🌧 Environmental changes
Changes in the environment affect food production. If the rains fail, crops die and widespread famine can follow in some countries.
💰 Cost of agricultural inputs
Farmers have to pay for things like seed, feed and fertiliser. If these cost too much, farmers may not be able to grow as much food.
⚔ Conflicts
Conflicts in some parts of the world affect the availability of water or food. Farmers cannot farm safely and food cannot reach people.
Why we need sustainable methods
The number of people on Earth is still going up, so more food is needed. The specification is clear that sustainable methods must be found to feed all people on Earth.
Key terms:
- Sustainable: a method that meets the needs of people today without using up resources or damaging the environment, so that food can still be produced in the future.
Common mistakes
Do not say food security is "having lots of food". It is having enough food to feed a population. Also, do not write "famine" as a factor on its own. Famine is the result. The factor is the failed rains, the pest or the conflict that causes it.
Making food production more efficient
Farmers want to turn as much of the energy in their animals' food into the animals' own biomass as possible. The biomass is what people eat. The efficiency of food production can be improved by restricting energy transfer from food animals to the environment. This is done in two ways.
🔒 Limiting movement
If animals are kept in small pens, they cannot move about much. Moving uses energy from respiration. Less movement means less energy is transferred to the environment, so more goes into growth.
🌡 Controlling temperature
If the animals are kept in a warm building, they lose less heat to their surroundings. They use less energy to keep warm, so more energy goes into growth.
There is a third method. Some animals are fed high protein foods to increase growth. Protein is needed to build new tissue, so the animals put on mass faster.
Farming that uses methods like these to get as much food as possible from a small area is called intensive farming.
Key terms:
- Intensive farming: farming methods that produce as much food as possible from the land and animals available.
Is intensive farming a good idea?
Many people have ethical objections to some modern intensive farming methods. Ethical means to do with what is right and wrong. You need to be able to weigh up the advantages and disadvantages.
✅ Advantages
More food from the same amount of land, so more people can be fed. Animals grow quickly, so there is a faster supply of meat. Less feed energy is wasted, so food can be cheaper.
❌ Disadvantages
Many people think it is wrong to keep animals in small, crowded pens where they cannot behave naturally. Heated buildings and special feed cost money and use resources. Animals kept close together can spread disease more easily.
Worked example
Two calves are fed the same amount of food. Calf A is kept in a small warm pen. Calf B roams a cold hillside. Calf A puts on more mass. Calf A uses less energy moving about and keeping warm, so more of the energy in its food goes into new biomass.
Common mistakes
In a fair comparison with the same amount of food, a bigger share of the energy ends up as growth. Do not just say the animals "use less food"; say where the energy goes. When asked to evaluate, give at least one advantage and one disadvantage, and finish with a judgement.
Exam-style question
Some farmers keep chickens in warm indoor sheds with little room to move. The chickens are fed a high protein diet.
(a) Explain why keeping the chickens warm and limiting their movement makes food production more efficient. [3 marks]
(b) Give one reason why some people object to this method of farming. [1 mark]
(c) Give one biological factor that threatens food security. [1 mark]
Model answer
(a) The chickens lose less heat to the surroundings, so they use less energy to keep warm (1). They use less energy moving about (1). So less energy is transferred to the environment and more goes into growth / biomass (1).
(b) Any one from: animals are kept in crowded conditions and cannot behave naturally; it is cruel / unethical (1).
(c) Any one from: increasing birth rate; changing diets; new pests and pathogens; environmental changes such as failed rains; cost of agricultural inputs; conflicts (1).
Exam tip
In "explain" questions about efficiency, always finish by saying where the energy goes: into growth or biomass instead of being transferred to the environment.