Ammonium Sulfate vs. Urea: What's the Difference?
Edited by Aimie Carlson || By Harlon Moss || Published on June 19, 2026
Ammonium sulfate is an inorganic salt used as a fertilizer and in industrial applications, while urea is an organic compound used mainly as a nitrogen-release fertilizer.
Key Differences
Ammonium sulfate ([NH₄]₂SO₄) is an inorganic compound commonly used as a soil fertilizer for its nitrogen content. Urea (CO(NH₂)₂) is an organic compound and a high-nitrogen fertilizer, produced both naturally and synthetically.
Ammonium sulfate provides nitrogen in ammonium form, which resists leaching and is slowly available to plants. Urea initially offers nitrogen in a quickly available form after being converted to ammonium in soil.
The use of ammonium sulfate can lower soil pH, making it suitable for alkaline soils. Urea, on the other hand, has a relatively neutral pH effect on the soil but can cause a temporary increase in soil acidity before it breaks down.
Ammonium sulfate is also used in industrial applications, such as in the production of flame retardants. Urea is used in a variety of non-fertilizer applications, including plastics, animal feed, and pharmaceuticals.
Ammonium sulfate is more stable and less volatile than urea, making it suitable for long-term crop nourishment. Urea is more concentrated in nitrogen content, but its volatility requires careful management when applied to fields.
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Comparison Chart
Chemical Nature
Inorganic salt ([NH₄]₂SO₄).
Organic compound (CO(NH₂)₂).
Nitrogen Form
Provides nitrogen in ammonium form.
Initially provides nitrogen in urea form.
Effect on Soil pH
Lowers soil pH, suitable for alkaline soils.
Neutral pH effect, but may increase soil acidity temporarily.
Industrial Uses
Used in flame retardants, water treatment.
Used in plastics, pharmaceuticals, animal feed.
Stability and Volatility
More stable, less volatile.
More concentrated, but can be volatile.
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Ammonium Sulfate and Urea Definitions
Ammonium Sulfate
Ammonium sulfate is also used in industrial processes.
Ammonium sulfate is integral in water treatment facilities.
Urea
Chemically, urea is a compound of carbon, nitrogen, oxygen, and hydrogen.
The chemical formula for urea is CO(NH₂)₂.
Ammonium Sulfate
Ammonium sulfate is a stable nitrogen source for crops.
For his long-growing crops, he preferred ammonium sulfate for its stability.
Urea
Urea is used in non-fertilizer applications like plastics.
Urea-formaldehyde resins are used in the manufacture of particle board.
Ammonium Sulfate
Ammonium sulfate is an inorganic salt used as a nitrogen fertilizer.
The farmer used ammonium sulfate to enrich his alkaline soil.
Urea
Urea can increase soil acidity transiently.
He was cautious with urea application to avoid temporary soil acidification.
Ammonium Sulfate
It is composed of ammonium ions and sulfate ions.
Ammonium sulfate's chemical formula is [NH₄]₂SO₄.
Urea
Urea is an organic compound widely used as a fertilizer.
Urea is a key component in modern agriculture for nitrogen enrichment.
Ammonium Sulfate
It helps in lowering soil pH for agricultural benefits.
To correct the high pH of his soil, he applied ammonium sulfate.
Urea
It provides quickly available nitrogen to plants after application.
To quickly green up his lawn, he applied urea fertilizer.
Urea
A water-soluble compound, CO(NH2)2, that is the major nitrogenous end product of protein metabolism and is the chief nitrogenous component of the urine in mammals and certain other animals. Also called carbamide.
Urea
A water-soluble organic compound, CO(NH2)2, formed by the metabolism of proteins and excreted in the urine.
Urea
Any N-substituted derivative of urea, with the general formula (R1R2N)CO(NR3R4).
Urea
A very soluble crystalline body which is the chief constituent of the urine in mammals and some other animals. It is also present in small quantity in blood, serous fluids, lymph, the liver, etc.
Urea
The chief solid component of mammalian urine; synthesized from ammonia and carbon dioxide and used as fertilizer and in animal feed and in plastics
FAQs
What makes urea volatile?
Its rapid conversion to ammonia in warm, wet conditions leads to volatility.
What are the industrial uses of ammonium sulfate?
Besides fertilizers, it's used in flame retardants and water purification.
Can urea be used as a feed additive for animals?
Yes, it's used as a protein supplement in animal feed.
What is the primary use of ammonium sulfate?
Its primary use is as a nitrogen fertilizer in agriculture.
Is urea a natural or synthetic compound?
Urea is both a natural bodily compound and industrially synthesized.
Is urea safe for all types of plants?
Generally, yes, but it should be used carefully to avoid nitrogen burn.
How does ammonium sulfate interact with other soil nutrients?
It can interact with calcium and magnesium, affecting their availability.
Is urea suitable for acidic soils?
Urea is generally neutral but can temporarily increase soil acidity.
How does temperature affect urea application?
Higher temperatures can increase urea's volatility and nitrogen loss.
Can ammonium sulfate be used on all crops?
Yes, but it's especially beneficial for alkaline soils.
How quickly does urea release nitrogen?
Urea releases nitrogen quickly once converted to ammonium in soil.
Is ammonium sulfate harmful to the environment?
When used properly, it's not harmful, but overuse can lead to soil acidification.
What precautions should be taken when applying ammonium sulfate?
Avoid over-application and consider soil pH and type.
How does urea benefit fast-growing plants?
Its quick nitrogen release is ideal for rapidly growing plants.
Can ammonium sulfate be used in organic farming?
It's not typically used in organic farming due to its synthetic nature.
Does ammonium sulfate affect soil microbes?
It can affect microbial activity, especially in alkaline soils.
What are the storage requirements for ammonium sulfate?
Store in a cool, dry place to prevent caking.
Does urea impact soil pH over time?
Its impact is usually temporary, but soil pH should be monitored.
Is urea harmful to pets or wildlife?
In large amounts, it can be harmful, so keep it out of reach of animals.
Can ammonium sulfate be mixed with other fertilizers?
Yes, but compatibility should be checked first.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Aimie CarlsonAimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.
