## 4 Conclusions and Perspectives  
To our knowledge, this study is the first to report results on the possible use of sorghum in the phytoattenuation of a TE-contaminated site in northern France. As reported for other cultivars, we demonstrated tolerance of both cultivars to high levels of TE pollution in field conditions and, consequently, their relevance in a phytotechnology strategy. Our study pointed out promising valorization options for biomass cultivated on a TE-contaminated site, such as biogas production. Even if both investigated sorghum cultivars presented an excluder behavior concerning TE, the Cd concentration measured in their biomass could be a limiting factor for valorization. Finally, the results of the growth parameters of the two sorghum cultivars showed that, irrespective of the site pollution, the pedo-climatic conditions of northern France are suitable for their development. Additional studies to reduce the Cd transfer in the plant should be performed to facilitate biomass valorization and to confirm the use of sorghum as a species adapted for phytoattenuation, notably cultivar Biomass 133. Further studies should be realized to ensure the suitability of these cultivars in the climate change context. Moreover, the phytoattenuation with annual crops, such as sorghum, could be considered as a local resource at a territory scale and could be included in a sustainable phytoattenuation strategy. \begin{table}
\begin{tabular}{c c c c c} \hline
**Area 2** & \begin{tabular}{c} **Cd Removal** \\ **(kg ha\({}^{-1}\) y\({}^{-1}\))** \\ \end{tabular} & \begin{tabular}{c} **Cu Removal** \\ **(kg ha\({}^{-1}\) y\({}^{-1}\))** \\ \end{tabular} & \
\begin{tabular}{c} **Pb Removal** \\ **(kg ha\({}^{-1}\) y\({}^{-1}\))** \\ \end{tabular} &
\begin{tabular}{c} **Zn Removal** \\ **(kg ha\({}^{-1}\) y\({}^{-1}\))** \\ \end{tabular} \\ \hline Sorghum Biomass 133 & 0.0292 & 0.0935 & 0.0163 & 2.888 \\ \hline Sorghum Trudan HL & 0.0275 & 0.0549 & 0.0050 & 1.973 \\ \hline \end{tabular}
\end{table} 
Table 5: Annual Cd, Cu, Pb, and Zn removal for the two cultivars after the biomass harvest. **Supplementary Materials:** The following are available online at [[https://www.mdpi.com/article/10.3390/app11083471/s1](https://www.mdpi.com/article/10.3390/app11083471/s1)]([https://www.mdpi.com/article/10.3390/app11083471/s1](https://www.mdpi.com/article/10.3390/app11083471/s1)). * **Author Contributions:** Conceptualization, [PERSON] ([PERSON]) and V.B. ; methodology, V.B., [PERSON] ([PERSON]), and A.P. ([PERSON]); formal analysis, A.P. ([PERSON]) and O.D. ; investigation, [PERSON] ([PERSON]) and V.B. ; resources, A.P. ([PERSON]) and R.G. ; data curation, A.P. ([PERSON]) and O.D. ; writing--original draft preparation, [PERSON] ([PERSON]); writing--review and editing, V.B., M.F.d.S., E.M., R.G. and I.Z. ; visualization, A.P. ([PERSON]) and O.D. ; supervision, V.B., E.M., M.F.d.S. and R.G. ; project administration, V.B., R.G. and E.M.; funding acquisition, V.B., R.G. and E.M. All authors have read and agreed to the published version of the manuscript. * **Funding:** This research was cofunded by the New-C-Land Project (Interreg France-Wallonie-Vlaanderen, with the support of the European Regional Development Fund, grant number:1.2.294), the OVAM, the Province WestFlanders and the Walloon Region. * **Informed Consent Statement:** Not applicable. * **Acknowledgments:** The authors thank Voies Navigables de France, which provided access to the field site. The authors are also grateful to [PERSON], [PERSON], [PERSON], and [PERSON] for their technical contribution during the sampling campaigns and chemical analyses. The seeds of sorghum were kindly provided by semencesdeprovenec.com. We thank the Interreg Project New-C-Land, who permitted the field experiment and the writing of this paper. We thank the anonymous reviewer for their comments, which greatly helped us to improve the manuscript. * **Conflicts of Interest:** The authors declare no conflict of interest.