The notion of management has undergone many changes during the past century. Nowadays, management is perceived as “specialized activity to achieve targets.” Skill in management is the single most important factor determining the economic and environmental performance of agroecosystems. Nutrient management is “management of nutrients to achieve agronomic and environmental targets;” it requires proper understanding of nutrient cycling, site- and farm-specific guidelines and technology, and often direct coaching. These activities are diverse and complicated, especially in mixed farming systems that involve both crop and animal production. To be effective, economic and environmental targets must be coherent, flexible, and controllable. They also must be defined and implemented quantitatively at strategic, tactical, and operational levels. Data from farms in Poland and The Netherlands are used to show how economic incentives, provided through governmental policies and measures in both countries, can improve nutrient-use efficiency by a factor of 2 on many intensively managed mixed farming systems.