# Explain how the use of fertilisers can help improve food security, and describe one problem that their overuse can cause.

> Edexcel GCSE Biology (1BI0) — 9.2 Food security · Explain · 4 marks

## Mark scheme (4 marks)

1. Fertilisers provide essential nutrients to the soil / plants
2. This improves plant growth / increases crop yield
3. Overuse of fertilisers can cause eutrophication (fertilisers run off into bodies of water causing algal blooms)
4. Algal blooms block light / decomposers break down dead algae reducing oxygen levels, harming aquatic organisms

## Key terms

- [fertilisers](https://www.gradenine.co.uk/glossary/fertilisers)
- [food security](https://www.gradenine.co.uk/glossary/food-security)

## Related

- [Revision notes for Edexcel GCSE Biology (1BI0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-use-of-fertilisers-72e6536b) · Published by Druglandscape Ltd.