Explain why ammonium nitrate is considered a suitable fertiliser for crops.

Cambridge International IGCSE Chemistry (0620) — 10.2 Fertilisers · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Ammonium nitrate is one of the most widely used nitrogen-containing fertilisers in modern agriculture.

Model answer (4 marks)

Ammonium nitrate supplies nitrogen, a key element for plant growth.

Nitrogen is required for the synthesis of proteins and chlorophyll, which are essential for healthy leaf and shoot development.

Ammonium nitrate is highly soluble in water.

Its solubility allows the nitrogen to be dissolved in soil water and taken up directly by plant roots.

Examiner tips

Use the exact phrase "source of nitrogen" and "soluble in water". Show the link between nitrogen and protein synthesis. Mention root uptake as the final step. Keep each point brief and to the point.

Common mistakes

Confusing ammonium nitrate with other nitrogen sources. Forgetting to state that it is soluble. Using vague terms like "good for plants" instead of specific functions.

Mark scheme (4 marks)

Ammonium nitrate contains nitrogen / is a source of nitrogen
Nitrogen is needed by plants to make proteins / for healthy leaf/shoot growth
Ammonium nitrate is soluble in water / dissolves in water
Solubility means it can be absorbed / taken up by the roots of plants

Key terms in this question

fertiliser · ammonium nitrate