Sphagnum farming

Sphagnum farming on peat soils is a form of paludiculture on raised bog sites. Paludiculture („palus“ – Latin „swamp“) is agriculture and forestry on wet and rewetted peatlands.

What is Sphagnum farming?

Torfmoos
Sphagnum spec.

Sphagnum farming is the cultivation of peat moss (Sphagnum) aiming for the production and harvest of peat moss biomass. For this purpose the Sphagnum is cultivated in order to gain renewable raw material for the production of horticultural growing media.

Potential sites for Sphagnum cultivation on peat soils are degraded former raised bog sites such as cut-over peat bogs or cultivated bogs, which are currently used as pastures and meadows. Alternatively, Sphagnum can also be cultivated on floating rafts on open water, former peat cuttings in degraded raised bogs or lakes which developed after open-cast lignite mining.

The cultivation of Sphagnum has many benefits:

  • Climate: Conservation of carbon fixed in peat and reduction of CO2 emissions by rewetting degraded peatlands
  • Environment: Reduction of the emission of pollutants into ground and surface water in comparison to agricultural land use; renewed function of water purification and water retention in peatlands as well as a local cooling effect due to increased water evaporation.
  • Wildlife: Habitats for rare and endangered Sphagnum species
  • Landscape: Conservation of open landscape.
  • Economy: Renewable alternative to depleting fossil raw materials, job creation and alternative means of income in rural areas as well as regional creation of value.
Background

Everyone of us consumes peat on a daily basis: either directly as potting soil or indirectly by consuming fruit and vegetables grown on peat. Peat is the most important and so far irreplaceable ingredient for the production of high quality growing media in horticulture. For this purpose 3 million cubic metres of low humified peatmoss peat are used annually in Germany only. Worldwide consumption amounts to 30 million cubic metres, which will be emitted into the atmosphere as CO2 after short time usage.

Low humified moss peat is formed in functioning peatlands by the peat moss Sphagnum. The peat mosses grow at the tip and die off at the bottom and in their waterlogged and acidic environment part of the plant matter becomes preserved and accumulates as low humified moss peat. In this manner a raised bog grows slowly upwards, about one millimetre per year.

In order to mine the moss peat for horticultural purposes, the fragile bog ecosystem is destroyed by drainage and the peat which took millennia to accumulate is mined in a matter of a few years. The carbon content which was stored within the peat is released as CO2 into the atmosphere after a relatively short period of time. With the peat strata being mined there also disappears a whole “archive“of landscape and human history.

As the resources of minable moss peat are almost exhausted in Western Europe, the German peat and compost industry increasingly imports moss peat from ever more distant regions. Since the fall of the Iron Curtain the peat comes mostly from the Baltic States in Eastern Europe. Germany as the currently largest producer and user of peat in commercial horticulture imported 1.8 million cubic metres of moss peat in 2006.

The potential economical consequences of increasingly longer import distances and scarcity of moss peat could be price increases of the growing media and an exodus of the horticultural industry out of Germany.

So far there has not been an alternative to peat that is equal in quality, at a similar price and available in large amounts.

Sphagnum biomass has the same properties as low humified moss peat and has been successfully tested in horticultural trials.

The cultivation of Sphagnum and the potential in the application of Sphagnum biomass have been/are investigated in four research projects at University of Greifswald.

Peat mining in the Dalumer Mire close to Meppen (University of Greifswald)
Peat mining in the Dalumer Mire close to Meppen (University of Greifswald)

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