How humans have increased food productionSpec 20.1.1
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.
The human population keeps growing, so more food is needed. Farmers have increased food production in five main ways.
| Method | What it does | How it increases production |
|---|---|---|
| Agricultural machinery | Tractors, ploughs and combine harvesters do the work of many people | Larger areas of land can be farmed and jobs are done faster and more efficiently |
| Chemical fertilisers | Add nitrates and other mineral ions to the soil | Replace ions removed by crops, so plants grow bigger and yields improve |
| Insecticides | Chemicals that kill insect pests | Fewer crops are eaten or damaged, so quality and yield improve |
| Herbicides | Chemicals that kill weeds | Reduce competition with weeds for light, water and ions |
| Selective breeding | Choosing parents with the best features to breed from | Crop plants and livestock with higher production, such as more grain or more milk |
Selective breeding takes many generations. Each time, the best offspring are chosen and bred together, so the useful feature becomes more common.
Give the reason as well as the method. 'Herbicides kill weeds so there is less competition for light and water' earns more than 'herbicides kill weeds'.
Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026