“…The contribution of ammonia volatilization is higher from wastes of domestic animal than from fertilizer use in China because domestic animal production has increased greatly since the late 1980s (Bouwman et al, 2002;Xiao et al, 2012Xiao et al, , 2013Liu et al, 2013). In Guiyang, southwest China, for example, the ammonium concentration has increased about for 1.8 times from 1984 to 2009 in rainwater (Galloway et al, 1987;Xiao et al, 2012). Excessive nitrogen inputs have led to debate on the nitrogen balance between aquatic and terrestrial ecosystems, and many negative effects on atmospheric environment and human health (Krupa, 2003;Huang et al, 2011;Hu et al, 2014).…”