Nitrous oxide mitigation potential of reduced tillage and N input in durum wheat in the Mediterranean

In Italy, managed soils account for about 50% of annual national emissions of nitrous oxide (N 2 O), thus the effect of agricultural practices on N 2 O emissions must be studied in order to develop mitigation strategies. Soil N 2 O emissions were measured in two field campaigns (2013–2014 and 2014–2015) on durum wheat in a Mediterranean environment to test the mitigation potential of reduced tillage and nitrogen (N) fertilization rate. N 2 O emissions were measured with a fully-transportable instrument developed during the project LIFE + IPNOA “Improved flux Prototypes for N 2 O emission reduction from Agriculture” and equipped with an infrared laser detector. Reducing tillage from ploughing to minimum tillage had no effect on average daily N 2 O flux, while decreasing the N rate from 170 to 110 kg N ha −1 reduced the average daily N 2 O flux, without negatively affecting the grain yield. Furthermore, N 2 O daily flux were positively correlated with soil water filled pore space, NO 3 -N, and NH 4 -N concentrations, and they were largely variable between the two field campaigns as a result of different environmental and management conditions (i.e.: rainfall, different amount of crop residues incorporated in soil). Overall, the innovative fully-transportable instrument performed well in the field and allowed us to conclude that decreasing the N fertilizer rate was a valuable option to mitigate N 2 O emissions without negative effects on wheat productivity.