At the beginning of the experiment, the addition of digestate to the Deoxycholic acid resulted in higher emissions of N2O than from the other treatments (Fig. 3a, b, c), even though there were seldom statistical differences between the treatments. Only Pyro-W emitted significantly less N2O in two days, August 29th 2013 and September 12th 2013, compared to Pyro-W + D (P < 0.05). The cumulative annual emission in the form of N2O-N ranged from 0.60 kg ha− 1 (Pyro-M-t) to 1.01 kg ha− 1 (digestate) ( Table 4). On average, 9.41 μg N2O-N m− 2 (control), 12.12 μg N2O-N m− 2 (digestate), 8.69 μg N2O-N m− 2 (Pyro-M), 7.05 μg N2O-N m− 2 (Pyro-M-t), 10.78 μg N2O-N m− 2 (HTC-M), 10.83 μg N2O-N m− 2 (HTC-M-t), 8.22 μg N2O-N m− 2 (Pyro-W) and 7.84 μg N2O-N m− 2 (Pyro-W + D) were emitted. Of the tertiary structure N applied, between 0.4 and 0.7% was lost as N2O.