Wetland cultivation

Use wetlands for nature-inclusive agriculture and water treatment

Rewetting peatlands is a necessary measure to reduce land subsidence and CO2 emissions and to restore nature. In buffer zones around nature areas water levels also need to be raised to enable nature restoration. But the application of many standard agricultural methods is almost impossible on rewetted, former agricultural areas on peatlands. Furthermore, nature development taking place on these lands does not lead directly to the restoration of natural features. 

The rewetting of peatlands and other agricultural land calls for an approach in which the economic value is preserved and the management preferably contributes to meeting the societal challenges concerning water, biodiversity and climate. The elaboration of such an approach depends strongly on the complex interaction between water, soil and management. Thorough process knowledge is needed for the development of applicable solutions.

Methods, tools and products

KWR researches the possibilities of alternative forms of agriculture on rewetted and former agricultural lands, in which the management simultaneously helps meet the societal challenges in the area of water management and those of climate mitigation. In doing so, we carry out field trials which involve the cultivation, among others, of bullrush and the use of test ponds, in which conditions can be effectively controlled. We conduct measurements in the field trials to assess the feasibility of wetland cultivation, and whether it simultaneously contributes to the retention and treatment of water. One of the challenges this entails is the prevention of the emission of greenhouse gases, such as methane and nitrous oxide, which can form as a result of rewetting. With the test ponds we clarify the relation between flow rate and water treatment, crop evapotranspiration and biomass production.

Projects

KWR conducts wetland cultivation research in various projects:

  • In producing crops on peatlands, it is important that a contribution be made to lower greenhouse gas emissions, less land subsidence, improved water quality and greater biodiversity. Therefore, within the Netherlands Peatland Innovation Programme (VIPNL), a project has been launched on Wetland crops on water-rich peat. This study focusses on factors associated with the cultivation of wetland crops (plants, water, soil, management), biodiversity, greenhouse gases, market and chain development, legislation and regulations, and value creation for ecosystem services.
  • In the TKI project, Rendabele Kringlooplandbouw in Veenweiden (Profitable circular agriculture in peatlands), higher groundwater levels in peatland areas are combined with the cultivation of wet crops (i.e., paludiculture) and can produce a win-win situation. The groundwater level in peatland lots is raised in the summer period through the input of water via adjustable drainage and subirrigation. The objective is to reduce soil subsidence and greenhouse gas emissions, but it can also lead to higher discharges of nutrients in wet periods, and thereby to deteriorated water quality. But wetland cultivation actually needs nutrients and can, at the same time, treat the contaminated water. The harvested wetland crops can be used as building and insulation material, or as a substitute for turf/peat in substrates.

Want to know more? Contact our experts

  • Jelmer Nijp PhD
    Jelmer Nijp PhD
    Scientific researcher
  • Jeroen Geurts PhD
    Jeroen Geurts PhD
    Scientific researcher