The number must be clear, legible and appear prominently and conspicuously on the label in proximity to the brand name or guaranteed analysis. The label shall also include a grade in close proximity to the brand. If sold in bulk, five labels containing all the required information must accompany a delivery ticket that shows the certified net weight of the bulk material. The chlorine content is guaranteed as the maximum percentage present, when applicable, in agricultural fertilizer. A statement of the percentage of each form present in the fertilizer must be given.
Ammoniacal nitrogen includes all the ammonium forms of nitrogen in the fertilizer.
The guarantee may be shown as the water-soluble organic nitrogen only. If only urea nitrogen is present, the guarantee may be shown as urea nitrogen or water soluble organic nitrogen. Water-insoluble nitrogen originally meant such natural organic materials as dried blood and tankage. Insoluble sources may be materials such as urea-formaldehyde, isobutylidene diurea, magnesium ammonium phosphate, or other similar materials. A product made by coating urea with sulfur is also sparingly soluble for a period of time in the soil, but the method of analysis used in the fertilizer laboratory currently prohibits the characterization of the material as a water-insoluble nitrogen source.