Fertilizer in legal terms is any substance containing one or more recognized plant nutrients which is used for its plant nutrient content and which is designed for use or claimed to have value in promoting plant growth. The definition of commercial fertilizer may exclude unmanipulated animal and vegetable manure's, marl, lime, limestone, basic slag, gypsum and other materials or products. State and federal laws govern the contents, sales, and labeling of commercial fertilizers.
The following is an example of an excerpt from a state fertilizer law:
"...Each commercial fertilizer registrant shall report the guaranteed analysis by net weight of each registered fertilizer brand and the name and address of the registrant. No guaranteed analysis of complete fertilizer shall be allowed indicating fractional units of primary plant food. Provided, however, raw materials may be registered under a guarantee of the actual plant food content. In the case of bone meal, the phosphoric acid content shall be stated as a total, and its actual nitrogen content shall be stated. In the case of rock phosphate, both the total and available phosphoric acid content shall be stated....".
