Fertilizergrade

Fertilizer grade is a quality designation for chemical products intended for use as fertilizers. It specifies the plant nutrients a product provides and establishes acceptable impurity and physical quality limits so that the material is suitable for agricultural use. In many markets, the grade is defined by the nutrient content and is used to compare products and guide application rates.

Grades are most commonly expressed as the three numbers N-P2O5-K2O, representing the percentage by weight of nitrogen, phosphorus pentoxide (as P2O5), and potassium oxide (as K2O) in the fertilizer. For example, a product labeled 46-0-0 is pure nitrogen fertilizer (urea or anhydrous ammonia equivalents); 18-46-0 indicates a di-ammonium phosphate type; 0-0-60 indicates potash as potassium chloride. Some products also include information about other nutrients (secondary nutrients or micronutrients) or total labeled content.

Regulatory and standards frameworks vary by country and region. Fertilizer grade is typically governed by agricultural or fertilizer authorities, with requirements for labeling, permissible levels of contaminants (heavy metals, chlorides), moisture content, granulation or particle size, and solubility. Producers must verify that the product meets the stated grade before sale.

In practice, fertilizer grade affects formulation, pricing, import/export, and agronomic performance, helping farmers match fertilizers to crop needs and soil conditions.