The fertilizer industry, agronomists, consultants, farmers, and policymakers from around the world are starting to recognize the 4Rs as the basis for fertilizer best management practices. The International Plant Nutrition Institute (IPNI), the Canadian Fertilizer Institute (CFI), and The Fertilizer Institute (TFI) have prepared a style guide describing terminology related to the 4R nutrient stewardship concept (see 'Additional Resources' to your left!). The intent is to help those employing 4Rs to be more consistent in the terminology used in nutrient management education and research programs, and the development of policy.
A complete set of 4R oval diagrams (with snapshots) is given below: