*3.1. Fluxes of CO2-C and N2O-N*

Marsch had the highest CO2-C flux, followed by Geest and the lowest in Östliches Hügelland (Figure 1). The flux of CO2-C progressively decreased with time in all the NI treatments under Marsch and Geest soils (Figure 1). In Marsch, DMPP had the lowest CO2-C flux during the incubation period (Figure 1, Table 2). CO2-C flux did not differ among the NI treatments during the incubation period in Geest soil (Figure 1). DCD, DMPP and PIADIN had the lowest CO2-C flux at 7 days of incubation in Östliches Hügelland soil (Figure 1).

Marsch had the highest N2O-N flux, followed by Östliches Hügelland and the lowest in Geest soil (Figure 2). Marsch and Östliches Hügelland soils with DCD and ENTEC applied had the lowest and the highest N2O-N flux, respectively, compared with the other NIs during the incubation period (Figure 2). In Geest, ENTEC showed the highest N2O-N flux during the incubation period while DMPP and PIADIN showed the lowest N2O-N flux (Figure 2).

**Figure 1.** The flux of CO2-C emission as affected by control, dicyandiamide (DCD), 3, 4-dimethylpyrazole phosphate (DMPP), nitrogenous mineral fertilizers containing the DMPP ammonium stabilizer (ENTEC) and active ingredients: 3.00–3.25% 1, 2, 4-triazole and 1.50–1.65% 3-methylpyrazole (PIADIN) treatments in Marsch, Östliches Hügelland and Geest soils. The data points are means of four independent pot replicates, and error bars represent standard errors of the means (*n* = 4).


**Table 2.** The F test values for CO2-C flux, N2O-N flux, NH4 +-N and NO3 −-N under different texture soils with four nitrification inhibitors applied.

**Figure 2.** The flux of N2O-N emission as affected by control, DCD, DMPP, ENTEC and PIADIN treatments in Marsch, Östliches Hügelland and Geest soils. The data points are means of four independent pot replicates, and error bars represent standard errors of the means (*n* = 4).
