## 3 Results
### N\(h_{4}\)-N and NO\({}_{3}\)-N Concentrations and Transformation Rates without DMPP  
NH\({}_{4}\)+-N and NO\({}_{3}\)-N concentrations and net rate calculations are reported in Table 2. The initial (t\({}_{0}\)) NH\({}_{4}\)+-N concentration of CNTR and NZ was very similar (\(p\) > 0.05), while that of CZ was significantly higher (\(p\) < 0.05). After 24 h (t\({}_{24}\)), the NH\({}_{4}\)+-N decreased (similarly) in CNTR and NZ, while it increased in CZ. This resulted in similar negative net rates for CNTR and NZ and a positive net rate for CZ (Table 2). The gross production and consumption rates of NH\({}_{4}\)+-N are reported in Figure 2. In CNTR and NZ treatments, consumption of NH\({}_{4}\)+-N was higher than production, which showed very low rates, while in CZ treatment, the production of NH\({}_{4}\)+-N exceeded consumption.  
NO\({}_{3}\)-N concentrations at t\({}_{0}\) were very similar in CNTR and NZ, and significantly higher in CZ (Table 2) (\(p\) < 0.05). NO\({}_{3}\)-N increased significantly in all the treatments at t\({}_{24}\) but all net nitrification rates were very similar (\(p\) > 0.05). The gross production and consumption rates of NO\({}_{3}\)-N are reported in Figure 3. Production of NO\({}_{3}\)-N exceeded consumption in all the treatments. The CNTR was characterized by the highest production of NO\({}_{3}\)-N, followed by NZ and CZ, which exhibited the lowest production rate (\(p\) < 0.05). Consumption rates were similar between the CNTR and NZ (\(p\) > 0.05), while no consumption was recorded in the CZ treatment (Figure 3).  
\(Nh_{4}\)\({}^{+}\)-N and NO\({}_{3}\)\({}^{-}\)N Concentrations and Transformation Rates with DMPP  
The t\({}_{0}\) NH\({}_{4}\)\({}^{+}\)-N content in treatments that received DMPP was very similar to those without DMPP. However, at t\({}_{24}\), the concentrations tend to be lower in CNTR and NZ while they increased in CZ. This resulted in slightly negative net rates in CNTR and NZ treatments and a high positive rate for CZ, with a significant effect of DMPP (\(p\) < 0.05) (Table 2). Gross production of NH\({}_{4}\)\({}^{+}\)-N was very low in both CNTR and NZ as in the treatments that did not receive DMPP, while in CZ, the production was further stimulated by DMPP addition (\(p\) < 0.05), resulting in the highest rates recorded (Figure 2). The consumption of NH\({}_{4}\)\({}^{+}\)-N was still prevailing over production in CNTR and NZ, but it was lower than in treatments that did not receive DMPP (\(p\) < 0.05). In CZ treatment, the consumption was similar between with and without DMPP addition.  
NO\({}_{3}\)\({}^{-}\)-N at t\({}_{0}\) in treatments that received DMPP was similar to that of treatments without DMPP (Table 2). However, at t\({}_{24}\), the concentrations did not change significantly in CNTR and NZ, resulting in very similar and low net rates (\(p\) > 0.05) and hence in a significant effect of DMPP (\(p\) < 0.05). The concentration of NO\({}_{3}\)\({}^{-}\)-N in CZ treatment decreased slightly at t\({}_{24}\), resulting in a negative net rate and a significant effect of DMPP (\(p\) < 0.05). Gross production of NO\({}_{3}\)\({}  
received DMPP with slightly lower rates in NZ compared to the CNTR (\(p\) \(<\) 0.05), while no production was recorded in the CZ treatment. Consumption rates of NO3 -N were, on the other hand, higher in treatments that received DMPP with CZ recording the lowest consumption rate (\(p\) \(<\) 0.05), while the CNTR and NZ were similar (\(p\) \(>\) 0.05).