Productivity and biomass quality of cattail (Typha spp.) on a 10 ha paludiculture pilot site in northeast Germany

The Paludi-PROGRESS project (Paludiculture in practice: Optimisation of cattail and reed cultures, project period 2022-2025) aims to test and further develop the cultivation of cattail (Typha spp.) as a new permanent crop on wet peatlands. One of the main tasks is to evaluate the productivity and biomass quality of cattail on a 10 ha rewetted peatland, established in September 2019.

In the time period of 2021 until 2024 biomass samples were collected twice a year, in summer (July) and winter (November/December). Prior to the first sampling in 2021, four different density categories were identified based on the visual impression of the cattail vegetation (dense to rare cattail plant occurrence). Sampling plots were randomly distributed within these sub-areas of the pilot site (10 per density category). Since a partial harvest took place on a small area in December 2021 and 2023, the influence of cutting on the biomass could also be observed in the following years. Furthermore, the site was fully harvested at the beginning of 2023. To monitor the cattail vegetation, several parameters were recorded for each plot: e.g. number of cattail plants and spadices, plant height and diameter, dry weight, water content and chemical composition (carbon, nitrogen, phosphorous, potassium, lignin, cellulose and hemicellulose).

From winter 2021 to winter 2024, cattail biomass productivity has more than tripled from 1.8 to 6.8 t dm/ha when considering the total pilot site. In the areas with dense cattail vegetation, the biomass increased from 4.1 to 8.2 t dm/ha. Different stand densities showed an influence on morphological parameters, but had a minor effect on the chemical composition of the biomass. The harvest trial in 2021 did not have a significant impact on the parameters considered. In winter 2023, the biomass productivity declined to 3.6 (total site) and 4.9 t dm/ha (dense areas). Next to other environmental factors, harvesting the total site could have shown a negative effect on the regrowth of cattail in 2023.

The collected data show unique results about the development of cattails on a large-scale pilot site and therefore provide important information for future use of cattail from commercial-scale cultivation. Additionally, it is important to evaluate whether the given growing conditions lead to appropriate biomass quality for various utilization options.