Oregon law defines the following:
- Agricultural amendment: A mixed or unmixed synthetic chemical substance, a chemically or physically modified natural substance, a naturally occurring substance or a manufacturing by-product, or a combination of those substances or by-products, intended to induce crop yields or plant growth or to produce any physical, microbial, or chemical change in the soil.
- Agricultural mineral: A mineral substance, mixture of mineral substances or mixture of mineral and organic substances containing less than five percent of total nitrogen (N), available phosphate (P2O5) or soluble potash (K2O), singly, collectively or in combination, designed for use principally as a source of plant food, in inducing increased crop yields or plant growth or producing any physical, microbial, or chemical change in the soil.
- Fertilizer: Any substance, or any combination or mixture of substances, that is designed for use primarily as a source of plant food, in inducing increased crop yields or plant growth, or producing any physical, microbial or chemical change in the soil, and that contains five percent or more of total nitrogen (N), available phosphate (P2O5) or soluble potash (K2O), singly, collectively, or in combination.
- Lime: Any substance or mixture of substances having calcium or magnesium compounds capable of neutralizing soil acidity.
See the law (ORS 633.311) for additional details.
Fertilizer Program policy
Humic Acid Analytical Methodology
Registration of Certain Plant Growth Regulator (PGR) Products
Requirement for a Cautionary Label Statement on Products Containing Certain Microbiological ingredients
Oregon Fertilizer Rules
Rules governing fertilizer, agricultural amendments and lime products Rule