Fertilizers: Identifying a Source of Nitrogen

Plants require several essential nutrients for healthy growth, and nitrogen (N) is one of the most crucial. It plays a vital role in the formation of proteins, nucleic acids, and chlorophyll, which is essential for photosynthesis. Fertilizers are substances added to soil or plants to supply nutrients. This question asks us to identify which of the given options is a source of nitrogen.

Analyzing Fertilizer Options

Let's examine each option to determine its primary nutrient content:

• Superphosphate: This is a common fertilizer primarily known for supplying phosphorus (P) to plants. It is typically produced by treating phosphate rock with sulfuric acid. While it contains calcium, its main contribution is phosphorus.
• Potassium sulfate: Also known as sulfate of potash, this fertilizer is a significant source of potassium (K) and sulfur (S). It is often used when plants need potassium but not additional chloride. Its chemical formula is \(K_2SO_4\).
• Bone meal: This organic fertilizer is derived from animal bones. It is a good source of phosphorus (P) and calcium (Ca). While bone meal does contain a small amount of nitrogen, it is not considered its primary nutrient contribution compared to phosphorus.
• Urea: Urea is a synthetic fertilizer that is widely used globally due to its high nitrogen content. Its chemical formula is \(CO(NH_2)_2\). It typically contains about 46% nitrogen, making it one of the most concentrated nitrogen fertilizers available. When applied to the soil, it is converted into ammonia and then nitrate, which plants can readily absorb.

Conclusion on Nitrogen Source

Based on the analysis of the primary nutrients provided by each fertilizer:

• Superphosphate: Primarily Phosphorus (P)
• Potassium sulfate: Primarily Potassium (K) and Sulfur (S)
• Bone meal: Primarily Phosphorus (P) and Calcium (Ca)
• Urea: Primarily Nitrogen (N)

Therefore, among the given options, Urea is the fertilizer that serves as a primary source of nitrogen.