Global Nutrient Flows and Cycling in Food Systems

Plants require 14 nutrient elements in specific amounts for growth and development, in addition to carbon dioxide, water, and photosynthetic active radiation. The most limiting nutrient elements are nitrogen, phosphorus, and potassium. This chapter briefly summarizes the driving forces of nutrient cycling and the changes in global nutrient flows and balances in agricultural systems and food systems, with a focus on nitrogen and phosphorus in food production‐consumption systems. The nitrogen cycle is a most complex nutrient cycle. Nitrogen exists in different forms, most of which are biologically, photochemically, or radiatively active. The phosphorus cycle serves as an example for the cycling of “immobile” elements, such as metals, cadmium, and magnesium. The availability of phosphorus in most soils limits crop production around the world. The specialization and agglomeration of food production systems was facilitated by transnational corporations