Balancing Economic, Environmental and Social Goals in Nutrient Management.

Application of the right nutrient source at the right rate, at the right time, and in the right place has recently become a commonly used phrase for describing appropriate nutrient stewardship within the context of sustainable cropping systems. Nutrient best management practices (BMPs) are the in-field manifestation of these four rights (4Rs). Moving beyond a slogan phase in discussing 4R nutrient management necessitates specification of how “right” is determined including the requirement of balanced support of the economic, social and environmental goals of sustainability. Such balancing is facilitated by defining sets of practical system performance indicators that are agreed to by stakeholders. Though the balancing is done by those that farm the land, definition of performance indicators and targets should be a shared task of stakeholders at farm, regional and national geographies. Sets of indicators usually include those reflecting crop yields and quality as well as those reflecting nutrient loss to the environment; and soil productivity and ecosystem services as well as net profit and resource use efficiencies; and many more that can pull a specific management decision in opposite directions. As balance is sought, practices offering benefits for multiple indicators hold premium value.  A nutrient BMP is based on scientific research, often refined with adaptive management, that shows the practice provides the best combination of economic, social and environmental performance for the specific site in question. However, defining the “best combination” may go well beyond scientific principles to include value judgments.