Rewetting of peatland is commonly accepted as a useful measure for counteracting climate change. To increase the acceptance, an agricultural use of fen plants is needed. In this study, the optimal harvest date of Typha latifolia, Typha angustifolia and Phalaris arundinacea regarding their biogas potential and biogas yield per hectare was identified. Furthermore, the influence of the chemical composition of Typha spp. and P. arundinacea on the biogas and biochemical methane potential was determined. Finally, the predictability of the biochemical methane potential (BMP) of Typha spp. and P. arundinacea by their composition with published regression models was examined. The three fen plant species were harvested on five different dates in 2018 and/or 2020. For each harvest, the biomass yield, biogas potential and BMP were determined, the chemical composition of the biomass was analyzed, and the biogas yield per hectare was calculated. The biogas potential of T. latifolia, T. angustifolia and P. arundinacea decreased with increasing plant maturity and ranged between 315 and 647 L_N kg⁻¹ VS, 405 and 596 L_N kg⁻¹ VS and 361 and 597 L_N kg⁻¹ VS, respectively. The biogas and BMP of all three plant species investigated were negatively correlated with the lignin content and could be predicted with published regression models, which included the lignin content as main regressor. The derived optimal harvest dates, which were a compromise between biomass yield and biogas potential, for all three fen plants ranged between the development stages of full flowering and shortly after the seed heads turned brown.

泥炭地的再润湿被普遍认为是应对气候变化的有用措施。为了提高接受度，需要将沼泽植物用于农业。在这项研究中，根据沼气潜力和每公顷沼气产量，确定了宽叶香蒲、狭叶香蒲和紫罗兰的最佳收获日期。此外，香蒲化学成分的影响。和P. arundinacea对沼气和生化甲烷潜力进行了测定。最后，香蒲生化甲烷潜力 (BMP) 的可预测性。和P. arundinacea通过它们与已发布的回归模型的组合进行了检查。三种蕨类植物在 2018 年和/或 2020 年的五个不同日期收获。对于每次收获，测定生物量产量、沼气潜力和 BMP，分析生物量的化学成分，并计算每公顷沼气产量. T. latifolia、T. angustifolia和P. arundinacea的沼气潜力随着植物成熟度的增加而降低，范围在 315 和 647 L _N kg ⁻¹ VS、405 和 596 L _N kg ⁻¹ VS 以及 361 和 597 L _N kg −^之间1个VS，分别。所调查的所有三种植物的沼气和 BMP 与木质素含量呈负相关，可以使用已发表的回归模型进行预测，其中木质素含量作为主要回归变量。推导出的最佳收获日期是生物量产量和沼气潜力之间的折衷，所有三种蕨类植物的最佳收获日期介于完全开花的发育阶段和种子头变成褐色后不久。