Scenarios of animal waste production and fertilizer use and associated ammonia emission for the developing countries

Livestock production and the use of synthetic fertilizer are responsible for about half of the global emission of NH 3. Depending on the animal category between 10 and 36% of the N in animal excreta is lost as NH 3. The current annual NH 3 emission in developing countries of 15 million ton N accounts for 2/3 of the global emission from animal excreta. In addition, 7.2 million tons NH 3N of synthetic N fertilizers are lost as NH 3 in developing countries. This is 80% of the global NH 3 emission from synthetic fertilizer's use. Along with human population increase and economic growth, livestock production in developing countries may even increase by a factor of 3 between now and 2025. The net result of rapid increase of livestock production combined with higher efficiency is an increase in NH 3 emissions of only 60% from 15 to 24 million tons NH 3N between 1990 and 2025 in developing countries. Livestock production is an important consumer of feedstuffs, mainly cereals, thereby inducing additional demand for synthetic fertilizers. Despite the projected major increase of synthetic fertilizer use from 42 to 106 million ton N between 1990 and 2025, the NH 3 loss in developing countries may decrease if a shift towards other fertilizer types, that are less vulnerable to NH 3 volatilization, is realized. According to the scenario, the total emission of NH 3 associated with food production in developing countries will increase from 22 to 30 million ton N yr -1 between 1990 and 2025. Although the NH 3 emission increases more slowly than food production, in particular, animal production may show geographic concentration in certain regions, which may lead to high local emission densities and associated environmental problems.