Stimulated by anaerobic conditions. Most common from manures and synthetic fertilizers. When N is applied to ecosystems in amounts greater than can be taken up by plants or stored in soil, it is lost to the environment, causing pollution. Though any type of organic or inorganic N can be overapplied, the availability of cheap and concentrated synthetic N fertilizer encourages overapplications. Rainfall enhanced with NO x causes acidification and N-saturation of ecosystems.
Nitrous oxide is a potent greenhouse gas.
Though N fertilizer prices are often subsidized in developing nations, dependency on synthetic N sources increases farmer vulnerability to world energy prices and to national and global politics. Recycling and use of local N resources can increase farmer autonomy. Nitrogen in Human Nutrition Humans require nitrogen in the form of protein, a critical component of the diet. Most humans receive their dietary protein from cereals, legumes and animal products, with the wealthier nations generally consuming more animal protein than developing nations. The Haber-Bosch process for industrial synthesis of ammonia from N 2 has profoundly altered global N biogeochemistry.