Fertilizer classification: Urea is classified as which type of plant nutrient fertilizer based on its primary nutrient content?

Introduction:
Fertilizers are categorized by the primary nutrient supplied: nitrogen (N), phosphorus (P), or potassium (K). Urea is one of the most widely used fertilizers globally due to its high nitrogen content and favorable handling characteristics.

Given Data / Assumptions:

• Urea chemical formula: CO(NH2)2.
• Typical nutrient analysis: 46% N by weight.
• Application: broadacre crops, horticulture, and blended products.

Concept / Approach:
Because urea contains only nitrogen as a primary nutrient (no P2O5 or K2O), it is categorized as a nitrogenous fertilizer. It can be used alone or as a component of compound blends, but its classification depends on its inherent nutrient makeup, not the blend it may be added to.

Step-by-Step Solution:
Identify nutrient content: high nitrogen, negligible phosphorus or potassium.Match with fertilizer category: nitrogenous.Confirm: Urea’s analysis (46-0-0) in N-P2O5-K2O terms supports the classification.

Verification / Alternative check:
Standard fertilizer labeling and agronomy texts list urea as a straight nitrogen fertilizer with the highest N content among common granular sources.

Why Other Options Are Wrong:

• Potassic or phosphatic: Urea contains neither K nor P as primary nutrients.
• Mixed NPK: While urea can be part of blends, the pure product is not a mixed NPK fertilizer.
• None of these: Incorrect because nitrogenous is correct.

Common Pitfalls:
Confusing fertilizer classification with application method; coating or stabilizers do not alter the primary nutrient category.

Final Answer:
nitrogenous