In this study, global greenhouse gases effect due to the use of
both mineral fertilizers was calculated using the default soil N2O
emission factor (EF) of 1% and the value of 0.8% derived from
experimental data of a Mediterranean maize crop (Fierro and Forte,
2012). Urea and ammonium nitrate showed, respectively, a 7.8%
and 4.9% reduced impact of N2O as greenhouse gases by using
direct field data of soil N2O emission factor (EF) than default value
of 1%. These results underline the need to use more precise data for
the accounting. In fact, in the 2006 IPCC Guidelines for National
Greenhouse Gases Inventory (IPCC, 2006) the value of EF has been
changed from 1.25% to 1%, as compared to the 1996 IPCC Guidelines,
as a result of new analyses of the available experimental data