Paludiculture: multifunctional land-use to decrease nutrient loading

To counteract soil subsidence and greenhouse gas emissions, groundwater levels in agriculturally used peatlands are increased in summer (e.g. by subsurface irrigation). This rewetting could lead to increased nutrient mobilization under anaerobic conditions in nutrient-rich soils, which will lead to eutrophication in ditches and lakes. However, rewetted peatlands can also be used to purify surface water and utilize the available nutrients by cultivation of wet crops like Typha and Phragmites, which is called “paludiculture”. These wet crops can provide raw materials for fiber based products (e.g. insulation and building materials). Paludiculture can also be implemented in multifunctional buffer zones along streams in sandy landscapes.

This multifunctional land-use can create a win-win situation that combines biomass production of wet crops with the provision of ecosystem services, such as peat preservation and water purification. To underpin what the water purification potential of paludiculture is, measurements have been done in several mesocosm experiments and field-scale paludiculture pilots within national and European projects (e.g. VIP-NL, KLIMAP, Carbon Connects and CINDERELLA). These pilots and experiments were used to learn how to cultivate paludiculture crops under different hydrological circumstances (water level and fluctuations), nutrient loads, water quality, soil types and field configurations. We quantified the nutrient uptake by Typha and Phragmites and the change in water quality between inlet and outlet in different situations. The results are also used to investigate which combination of factors will give the most efficient combination of water purification, nutrient uptake and biomass production.  In the end, this contributes to developing new ways of sustainable and economical feasible farming on wet peat soils and in brook valleys.