Agricultural solutions for a growing populationSpec 4.13B
In short
Fertilisers and biological control are agricultural solutions for feeding a growing human population. Fertilisers add mineral ions such as nitrates to the soil, increasing crop yield, but they can wash into rivers and pollute water. Biological control uses living organisms, such as ladybirds that eat aphids, to control pests without chemicals, but it is slower than pesticides.
The human population is growing, so more food is needed. Two agricultural solutions are the use of fertilisers and biological control.
Fertilisers
Fertilisers add mineral ions, such as nitrates, to the soil. Plants need these to grow well, so crop yields are higher.
- Advantage: increased growth and yield, so more food is produced from the same land.
- Disadvantage: fertilisers can be washed off fields into rivers and lakes, which can harm wildlife and pollute water.
- Disadvantage: they cost money, so the farmer's costs go up.
Biological control
Biological control is the use of living organisms to control pests. For example, ladybirds can be released to eat aphids.
- Advantage: no chemical residues are left on the food, and harmful chemical pesticides are not needed.
- Advantage: the control organism usually targets only the pest, and can keep working over a long time.
- Disadvantage: it is slower than pesticides and may not completely remove the pest.
- Disadvantage: the control organism might itself become a pest, or might eat other organisms, harming the ecosystem.
Questions about fertilisers or biological control need both sides. Give at least one advantage and one disadvantage, each explained, not just named.
Written and checked against the Edexcel GCSE Biology (1BI0) specification · Updated October 2026