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 responsib le for about half of the global emission of NH3. Depending on the anim al category between 10 and 36% of the N in animal excreta is lost as N H3. The current annual NH3 emission in developing countries of 15 mill ion ton N accounts for 2/3 of the global emission From animal excreta. In addition, 7.2 million tons NH3-N of synthetic N fertilizers are lo st as NH3 in developing countries. This is 80% of the global NH3 emiss ion from synthetic fertilizer's use. Along with human population incre ase and economic growth, livestock production in developing countries may even increase by a factor of 3 between now and 2025. The net resul t of rapid increase of livestock production combined with higher effic iency is an increase in NH3 emissions of only 60% from 15 to 24 millio n tons NH3-N between 1990 and 2025 in developing countries. Livestock production is an important consumer of feedstuffs, mainly cereals, the reby inducing additional demand for synthetic fertilizers. Despite the projected major increase of synthetic fertilizer use from 42 to 106 m illion ton N between 1990 and 2025, the NH3 loss in developing countri es may decrease if a shift towards other fertilizer types, that are le ss vulnerable to NH3 volatilization, is realized. According to the sce nario, the total emission of NH3 associated with food production in de veloping countries will increase from 22 to 30 million ton N yr(-1) be tween 1990 and 2025. Although the NH3 emission increases more slowly t han food production, in particular, animal production may show geograp hic concentration in certain regions, which may lead to high local emi ssion densities and associated environmental problems. (C) 1997 Elsevi er Science Ltd.