Let more growers get greater benefits

Home » Which is Better: Urea or Ammonium Sulfate?

Which is Better: Urea or Ammonium Sulfate?

Nitrogen fertilizers are essential for crop growth and high yields in modern agriculture. Among the most commonly used nitrogen sources are urea and ammonium sulfate, each with unique properties and applications. In this detailed guide, we will compare these two fertilizers across multiple dimensions to help farmers make informed, science-based decisions.

1. Overview of Urea and Ammonium Sulfate
1. Overview of Urea and Ammonium Sulfate

2. Chemical and Physical Properties Comparison
2. Chemical and Physical Properties Comparison

3. Fertilizer Efficiency and Crop Uptake
3. Fertilizer Efficiency and Crop Uptake

4. Environmental Impact and Safety
4. Environmental Impact and Safety

5. Recommended Crops and Application Methods
5. Recommended Crops and Application Methods

6. Cost and Economic Considerations
6. Cost and Economic Considerations

7. Summary and Recommendations
7. Summary and Recommendations

1. Overview of Urea and Ammonium Sulfate

Urea: Chemically known as carbamide, urea contains about 46% nitrogen, making it one of the highest nitrogen-concentration fertilizers available. It is typically in white crystalline or granular form. Urea converts to ammonium in soil, providing a readily available nitrogen source for crops. Risso urea fertilizers are highly soluble and widely used in global agriculture.
Ammonium Sulfate: With the chemical formula (NH₄)₂SO₄, ammonium sulfate contains around 21% nitrogen and provides sulfur as an additional nutrient. It exists in granular or powdered form and is particularly suitable for alkaline soils due to its acidifying effect. Risso ammonium sulfate delivers both nitrogen and sulfur efficiently for sulfur-deficient crops.

2. Chemical and Physical Properties Comparison

Property	Urea (Risso®)	Ammonium Sulfate (Risso®)
Nitrogen Content	~46%	~21%
Form	Crystalline or granular	Granular or powder
Solubility	Highly soluble	Moderately soluble
Soil pH Impact	Minimal	Lowers soil pH, ideal for alkaline soils
Sulfur Content	None	Contains sulfur

3. Fertilizer Efficiency and Crop Uptake

Urea: High nitrogen content ensures rapid fertilization. Best for nitrogen-demanding crops like corn, wheat, and rice. However, urea is prone to ammonia volatilization, especially in warm or dry conditions. Using Risso urea fertilizers with controlled-release or proper application techniques can minimize losses.
Ammonium Sulfate: Provides a more stable nitrogen release and additional sulfur, which is essential for crops like oilseed rape, peanuts, and onions. Risso ammonium sulfate ensures steady nutrient supply while improving soil sulfur levels.

4. Environmental Impact and Safety

Urea: Ammonia volatilization can lead to nitrogen loss and environmental concerns. Application timing is crucial—preferably early morning or late evening. Using Risso® urea with enhanced formulations reduces nitrogen losses and increases crop efficiency.
Ammonium Sulfate: Acidifies the soil, which benefits alkaline soils but may cause long-term soil acidification if over-applied. Responsible application of Risso ammonium sulfate ensures balanced soil fertility without adverse environmental effects.

5. Recommended Crops and Application Methods

Urea: Ideal for most staple crops with high nitrogen requirements, such as wheat, maize, and rice. Recommended during early vegetative growth and tillering stages. Avoid high-temperature applications to reduce nitrogen loss.
Ammonium Sulfate: Suitable for crops with high sulfur demand, including oilseed crops, legumes, and alliums. Apply during early growth and flowering stages. Risso ammonium sulfate is formulated for optimal solubility and nutrient availability.

6. Cost and Economic Considerations

Factor	Urea	Ammonium Sulfate
Market Price	Generally lower	Relatively higher
Storage and Transport	Easy to transport and store	Requires moisture protection
Crop Suitability	Broad application	Suitable for specific crops and soil types

7. Summary and Recommendations

Factor	Recommended Fertilizer
High nitrogen-demand crops	Urea
High sulfur-demand crops	Ammonium Sulfate
Alkaline soil regions	Ammonium Sulfate
Cost-effectiveness	Urea

FAQ (Frequently Asked Questions)

Q1: Can urea and ammonium sulfate be mixed for application?

A1: It is generally not recommended, as mixing may increase nitrogen losses. Use them in separate applications or split applications for optimal crop uptake.

Q2: What happens if urea is applied during hot weather?

A2: High temperatures can cause ammonia volatilization, reducing nitrogen efficiency. Use Risso® urea fertilizers early in the morning or late in the evening to minimize losses.

Q3: How does ammonium sulfate affect soil pH?

A3: It lowers soil pH and is beneficial for alkaline soils. Long-term excessive use may cause soil acidification, so proper application rates are essential.

By selecting the right nitrogen fertilizer, farmers can improve crop yields, reduce nutrient loss, and maintain sustainable soil fertility. Risso fertilizers offer high-quality urea and ammonium sulfate products optimized for professional agricultural use, helping growers worldwide achieve the best results.