At the agricultural inputs level, organic manure
contributed the largest share of global warming in both organic and
conventional tomato production, 89.94% for organic and 54.94% for
conventional tomato production, respectively. With regards to the
emission levels, the main greenhouse gas was N2O, which
accounted for 69.16% in the organic system and 54.24% in the
conventional system. This goes in line with previous findings in the
wheat system (Biswas et al., 2010).