Food supply — Cambridge IGCSE Biology
How farming methods raise food production, and the advantages and disadvantages of monocultures and intensive livestock production.
Revision notes
2 short notes, in the order of the specification. Each one in short:
Humans have increased food production in five main ways: agricultural machinery, chemical fertilisers, insecticides, herbicides and selective breeding. Machinery lets larger areas be farmed efficiently. Fertilisers replace mineral ions removed by crops, insecticides kill insect pests, and herbicides kill weeds so there is less competition for light, water and ions. Selective breeding gives higher-producing crops and livestock.
A monoculture is the growing of a single crop plant on a large area of land, often every year. It is efficient and gives high yields, but biodiversity is low and pests or disease spread quickly. Intensive livestock production keeps many animals in small spaces, producing cheap food but raising welfare concerns, disease spread and pollution.
Exam questions
6 exam-style questions (20 marks), each with its mark scheme.
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The whole of human influences on ecosystems on one page, so you can see where this subtopic fits.
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Quick check questions
Name five ways humans have increased food production.
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Machinery, chemical fertilisers, insecticides, herbicides and selective breeding.
What is a monoculture?
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The growing of a single crop plant on a large area of land.
Give one disadvantage of a monoculture.
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A pest or disease can spread quickly through the crop (or low biodiversity).
Give one advantage of intensive livestock production.
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Lots of food is produced from a small area, at a lower cost.
Frequently asked questions
How have humans increased food production?
Humans have increased food production using agricultural machinery, chemical fertilisers, insecticides, herbicides and selective breeding. Machinery lets larger areas be farmed faster. Fertilisers replace mineral ions taken up by crops, improving yields. Insecticides reduce crop damage by insect pests, herbicides reduce competition from weeds, and selective breeding produces higher-yielding crops and livestock.
What are the disadvantages of monocultures?
Monocultures have low biodiversity, because only one crop species is grown and hedges and wild habitats may be removed. A pest or disease that attacks the crop can spread quickly through the whole field. Growing the same crop every year removes the same ions from the soil, so large amounts of fertiliser are needed, which can pollute nearby water.
What are the advantages and disadvantages of intensive livestock farming?
Intensive livestock farming produces a lot of meat, milk or eggs from a small area at a lower cost, and less energy is lost as heat because animals move little and are kept warm. However, crowded animals may suffer stress, disease spreads easily so antibiotics may be overused, and large amounts of waste can pollute water.
Why do farmers use herbicides?
Farmers use herbicides to kill weeds, so there is less competition between the weeds and the crop for light, water and mineral ions. With less competition, the crop plants grow better and the yield increases. In exams, give the reason as well as the method: herbicides kill weeds so there is less competition.
Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026