Global NH3 Emission Inventory for Agricultural Lands

Information taken from 1,667 NH3 volatilization measurements documented in 148 research papers was summarized to assess the influence on NH3 volatilization of crop type, fertilizer type, and rate and mode of application and temperature, as well as soil organic carbon, texture, pH, CEC, measurement technique, and measurement location. The data set was summarized in three ways: (1) by calculating means for each of the factors mentioned, in which findings from each research paper were weighted equally; (2) by calculating weighted median values corrected for unbalanced features of the collected data; and (3) by developing a summary model using linear regression based on weighted median values for NH3 volatilization and by calculating global NH3 volatilization losses from fertilizer application using 0.5° resolution data on land use and soils. The calculated median NH3 loss from global application of synthetic N fertilizers (78 million tons N per year) and animal manure (33 million tons N per year) amount to 14% (10–19%) and 23% (19–29%), respectively. In developing countries, because of high temperatures and the widespread use of urea, ammonium sulfate, and ammonium bicarbonate, estimated NH3 volatilization loss from synthetic fertilizers amounts to 18%, and in industrialized countries it amounts to 7%. The estimated NH3 loss from animal manure is 21% in industrialized and 26% in developing countries. References: Bouwman, A. F., L. J. M. Boumans, and N. H. Batjes (2002), Estimation of global NH3 volatilization loss from synthetic fertilizers and animal manure applied to arable lands and grasslands, Global Biogeochem. Cycles, 16(2), 1024, doi:10.1029/2000GB001389. FAO/IFA (2001) Global estimates of gaseous emissions of NH3, NO and N2O from agricultural land. Food and Agriculture Organization of the United Nations, International Fertilizer Industry Association, Rome.

本数据集整合了148篇研究论文中记录的1667组氨（NH3）挥发实测数据，旨在评估作物类型、肥料类型、施用量与施用方式、温度，以及土壤有机碳、质地、pH值、阳离子交换量（CEC, Cation Exchange Capacity）、测定方法和测定点位对氨挥发的影响。数据集采用三种方式进行汇总：(1) 对前述各影响因子计算均值，此时每篇研究论文的研究结果均赋予同等权重；(2) 针对采集数据的非均衡特征进行校正后，计算加权中位数；(3) 基于氨挥发加权中位数构建线性回归汇总模型，并通过分辨率为0.5°的土地利用与土壤数据，估算全球肥料施用引发的氨挥发总损失量。
经计算，全球施用合成氮肥（年施用量7800万吨氮）与畜禽粪便（年施用量3300万吨氮）对应的氨挥发损失率分别为14%（10%~19%）与23%（19%~29%）。其中，发展中国家因气温较高且普遍施用尿素、硫酸铵与碳酸氢铵，合成氮肥对应的氨挥发损失率估算为18%；而发达国家该数值为7%。畜禽粪便的氨挥发损失率在发达国家为21%，发展中国家则为26%。
参考文献：
1. Bouwman, A. F., Boumans, L. J. M. 与 Batjes, N. H. (2002), 《估算施用于耕地与草地的合成氮肥与畜禽粪便引发的全球氨挥发损失》, 《全球生物地球化学循环（Global Biogeochem. Cycles）》, 16(2), 1024, doi:10.1029/2000GB001389.
2. 联合国粮食及农业组织/国际肥料工业协会（FAO/IFA）(2001), 《农田氨、一氧化氮与一氧化二氮气态排放的全球估算》, 联合国粮食及农业组织、国际肥料工业协会, 罗马.