Definition

Grade:

The percentage of total nitrogen, available phosphoric acid, and soluble potash stated in whole numbers in the same terms, order, and percentages as in the "guaranteed analysis." Specialty fertilizers may be guaranteed in fractional units of less than one percent of total nitrogen, available phosphorus or phosphoric acid, and soluble potassium or potash. Fertilizer materials, bone meal, manures, and similar materials may be guaranteed in fractional units.