Three Qualitative Sustainability Assessments in Three Countries Comparing the Reuse of Brownfield Land for Nettle Fiber Production With Alternative Land Management Scenarios

The increasing demand for bio‐based fibers as substitutes for synthetic materials raises concerns about land use competition with food production. One proposed solution is the cultivation of non‐food fiber crops on marginal or brownfield land. This study evaluates the sustainability of cultivating stinging nettle ( Urtica dioica L.) for fiber production under poplar ( Populus spp.) as a multifunctional land management strategy on brownfield and industrially impacted sites. Three qualitative sustainability assessments were conducted at case study sites in France (Saint‐Symphorien‐sur‐Saône), Italy (Tavazzano), and Germany (Bernburg), comparing nettle–poplar systems with alternative land management scenarios, including ecological succession (“no change”), conventional agriculture, and photovoltaic (PV) energy production. The assessments were undertaken ex ante between 2020 and 2022 in accordance with ISO 18504:2017 on sustainable remediation and applied the Sustainable Remediation Forum–UK (SuRF‐UK) Tier 1 qualitative framework. Environmental, economic, and social indicators were selected and scoped on a site‐specific basis using the SuRF‐UK indicator checklist, followed by comparative ranking of options supported by documented lines of evidence. Stakeholder engagement, involving site owners, technical experts, regulators, local authorities, and community representatives, was integrated into the assessment process and used to refine indicator selection and rankings. Across all three sites, nettle cultivation beneath poplar consistently achieved the most balanced sustainability performance overall, ranking highest for the environmental dimension in each case. Key environmental benefits included improved soil functionality, reduced erosion risk, enhanced ecological value, and productive reuse of marginal land. Economic performance of the nettle–poplar option was competitive but context dependent, generally ranking equal to or below PV‐based options for direct financial returns, while outperforming alternatives in employment, innovation potential, and wider induced benefits. Social outcomes varied by site, with ecological succession often favored where recreational or cultural values dominated, and novel bio‐based systems scoring lower on uncertainty due to limited operational track records. The results demonstrate that nettle–poplar systems represent a robust, nature‐based, and multifunctional option for the sustainable management of brownfield land, offering strong environmental performance and acceptable economic and social outcomes. The study highlights the value of qualitative, stakeholder‐informed sustainability assessment in supporting land‐use decision‐making where quantitative data are limited or highly site‐specific.