NPK Fertilisers

What does NPK stand for in NPK fertilisers?

Nitrogen (N), Phosphorus (P), and Potassium (K).

Why are NPK fertilisers important for agriculture?

They provide essential nutrients that promote plant growth, improve crop yields, and replenish soil nutrients.

How is ammonium nitrate produced in the laboratory?

By reacting ammonia (NH₃) with nitric acid (HNO₃) to form ammonium nitrate (NH₄NO₃).

What are the advantages of ammonium nitrate as a fertiliser?

High nitrogen content, easily absorbed by plants, and enhances crop productivity.

How is phosphate rock processed to make fertilisers?

It is treated with acids like sulfuric acid, nitric acid, or phosphoric acid to form soluble fertilisers like superphosphate.

What is a single superphosphate fertiliser?

It is calcium sulfate and calcium phosphate, produced by reacting phosphate rock with sulfuric acid.

Why is potassium essential for plant growth?

Potassium regulates water movement in plants and is essential for enzyme activation and photosynthesis.

What role does nitrogen play in plant growth?

Nitrogen is crucial for protein synthesis, leaf growth, and overall plant development.

What is a triple superphosphate fertiliser?

A fertiliser containing high levels of phosphorus, produced by reacting phosphate rock with phosphoric acid.

Why is it important to control the pH of fertilisers?

To prevent damage to plant roots and ensure nutrients remain soluble and accessible.

How does the Haber process relate to fertiliser production?

It produces ammonia, a key component for making nitrogen-based fertilisers.

What environmental problems can arise from overusing NPK fertilisers?

Eutrophication, soil degradation, and contamination of water supplies with nitrates.

How are fertilisers tested for nutrient content?

Using chemical analysis techniques like flame tests or spectroscopy.

What are slow-release fertilisers, and why are they beneficial?

Fertilisers that release nutrients gradually, reducing nutrient loss and improving efficiency.

Why are synthetic fertilisers often preferred over organic fertilisers?

They have precise nutrient ratios, are fast-acting, and are easier to transport and apply.