Sevenfold variation in global feeding capacity depends on diets, land use and nitrogen management
The number of people in the world that could theoretically be fed depends on how much food can be produced, as well as factors such as dietary composition (particularly the balance between crop and animal products) and what agricultural land is used for which purpose (cropping versus grazing). The potential for agricultural production is itself critically dependent on nitrogen availability. Nitrogen can be delivered in the form of mineral or organic fertiliser. While nitrogen is an essential input into agricultural production, nitrogen pollution is a major problem, with the degree of pollution caused a function of the quantity of nitrogen produced as well as the efficiency of its uptake and use by crops ( these will be influenced by climatic and other biophysical factors) - the Nitrogen Use Efficiency (NUE).