## 3 Results
### Soil Co\({}_{2}\) Fluxes  
Our hypothesis that urea fertilizer produces the highest CO\({}_{2}\) fluxes among all treatments was not supported, as CO\({}_{2}\) fluxes in the urea fertilizer treatment plots were only greater than those of the hydrochar treatment plots. Digestate treatment plots produced greater CO\({}_{2}\) fluxes than the hydrochar treatment plots, although the difference was not statistically significant. Hydrochar treatments trended toward reducing CO\({}_{2}\) fluxes compared to the other treatments. The hydrochar treatment produced the lowest net cumulative CO\({}_{2}\) fluxes with 34% lower CO\({}_{2}\) flux than the control in site A. This result is contrary to other studies [36; 50; 51] that found a higher production of CO\({}_{2}\) with hydrochar application. This difference could be due to differences in the biodegradation rates of the feedstocks used in making the hydrochar [50]. Secondly, [PERSON] et al. [49] notes that differences in processing temperature and time of hydrochar could lead to differences in the amount of C mineralized in soil. In the field, moisture variability could influence the rate at which microbial organisms degrade the C in the hydrochar, resulting in less C emission when soil moisture is low. Digestate, control, and urea treatments had similar mean weekly CO\({}_{2}\) fluxes. Compared to other studies where different rates of N fertilizers were applied to miscanthus, soil CO\({}_{2}\) fluxes measured in this study were similar in magnitude [27]. Samples for this study were collected over a period of five months, thus the cumulative fluxes were lower than others reported in the literature that evaluated year round soil flux ([PERSON] et al., 2017; [PERSON] et al., 2018; [PERSON] et al., 2018). Mean cumulative CO\({}_{2}\) fluxes in [PERSON] et al. (2018) ranged from 8.62 Mg C ha\({}^{-1}\) in control plots to 9.11 Mg C ha\({}^{-1}\) in plots treated with 60 kg N ha\({}^{-1}\) and 8.62 Mg C ha\({}^{-1}\) in plots treated with 120 kg N ha\({}^{-1}\). They also reported that fertilizer treatment did not significantly affect mean cumulative CO\({}_{2}\) fluxes from 4-year-old miscanthus stands. The mean of CO\({}_{2}\) emissions in the study by [PERSON] et al. (2016) was 50 mg C m\({}^{-2}\) h\({}^{-1}\) for N-fertilized plots and 47 mg C m\({}^{-2}\) h\({}^{-1}\) for unfertilized plots. In this study, miscanthus plots fertilized with N had a mean CO\({}_{2}\) emission of 0.340 mg C m\({}^{-2}\) h\({}^{-1}\) while unfertilized miscanthus plots had a mean CO\({}_{2}\) flux of 0.374 mg C m\({}^{-2}\) h\({}^{-1}\). [PERSON] et al. (2017) reported mean CO\({}_{2}\) fluxes of 0.23 mg C m\({}^{-2}\) h\({}^{-1}\) for miscanthus which is similar to this study's reported mean instantaneous CO\({}_{2}\) fluxes in all treatments ranging from 0.246 to 0.374 mg C m\({}^{-2}\) h\({}^{-1}\). Overall, this study resolved mean instantaneous CO\({}_{2}\) emissions as 0.374 mg C m\({}^{-2}\) h\({}^{-1}\), 0.342 mg C m\({}^{-2}\) h\({}^{-1}\), 0.340 mg C m\({}^{-2}\) h\({}^{-1}\), 0.246 mg C m\({}^{-2}\) h\({}^{-1}\) in the control, digestate, urea and hydrochar treated plots, respectively, which were lower than mean CO\({}_{2}\) fluxes in [PERSON] et al. (2016) but similar to those in [PERSON] et al. (2017). It can thus be inferred that applying these four fertilizer types to achieve the same added-N content will not result in significant differences in CO\({}_{2}\) fluxes but there might be an advantage to applying hydrochar. Soil temperature and soil moisture are important factors for explaining differences in trace gas emissions from soils ([PERSON] et al., 2016). An increase in soil temperature leads to greater emissions and to higher soil respiration rates due to increased microbial metabolism ([PERSON] et al., 2016). Results from this current study show significant cumulative increase in CO\({}_{2}\) fluxes in week 7 of sampling (Figures 2 and 3). This increase could be explained by the higher temperatures that characterize the last week of July.