Sub-regional dimensions of agricultural and environmental nitrogen:The case of Asia

查看全文 作　　者：John Keith [1]Syers 机构地区：[1]School of Science Mae Fah Luang University,Chiang Rai 57100,Thailand 出　　处：《Science China(Life Sciences)》索引2005年第48卷第z2期,共7页 摘　　要：Asia embraces a wide range of cropping environments, largely related to the diversity of climate. To meet the high food requirements of a very large population (some 59% of the earth's total) large inputs of mineral N fertilizer are required (44.2 Tg N.yr-1 in the mid 1990s).However, because of the low (20%-50%) overall efficiency of use of fertilizer N, sometimes coupled with heavy use in intensively-farmed areas (for example in parts of China), losses of fertilizer N from agricultural land are expected to be high. Part of the N lost is thought to cause pollution of the atmosphere and water resources.A sub-regional approach, based on the FAO Agroecological Zone (AEZ) concept, has the potential to provide meaningful assessments of the agricultural and environmental dimensions of N.The AEZ concept can also provide the rationale for locating Sub-regional Centers of the International Nitrogen Initiative (INI) by basing the considerations, as far as practicable, on agroecological conditions. 关 键 词：FERTILIZER nitrogen, loss processes, use efficiency, ATMOSPHERIC and water pollution, agroecological zones.