Peatland use – is drainage necessary?

Drainage for agricultural purposes – damned if you do, damned if you don’t.

Effective drainage is a key factor in the management of peat soils.

Peat may be a highly productive growing medium but peat soils need to be drained and cultivated to establish productive pastures and crops. However, this leads to irreversible shrinkage and oxidation (loss of carbon as carbon dioxide) of soil organic matter.

Peat shrinkage is estimated to occur at about 20 cm per year after the initial cultivation, reducing to 2 cm per year as the peat becomes more compact and resilient.

Too much drainage of peatlands can also reduce water levels in neighbouring ecosystems.

If we don’t manage our peat carefully, it will continue to shrink until eventually there will be no peat left.

Some peat soils have a layer of degraded peat, which we call moorsh or muck (depending on the admixture of mineral fraction).

• To preserve good quality peat, the water table should remain above the boundary of the moorsh and peat for as much of the year as possible.

• Maintaining a dense pasture sward is one of the best ways to protect your peat soil.

• Overgrazing should be avoided – any bare patches of peat will shrink faster, resulting in an uneven surface.

One important solution is paludiculture, which offers innovative opportunities for securing carbon and offering alternative livelihoods for people dependent on organic soils for their living.

from Latin: palus – swamp or wetland, cultura - culture

Conventional land use of peatlands requires drainage, which causes several problems:

- greenhouse gas emissions,

- nutrient efflux,

- loss of biodiversity,

- soil degradation,

- increasingly impaired land use options.

Paludiculture is better because peatlands may perform their functions:

- climate change mitigation (avoidance of N2O and CO2 emissions and provision of cool humid air)

- habitats for rare and threatened species

- renewable fuels and raw materials

- perspectives for agriculture and tourism

- water regulation

- no peatland fires

The global area of peatlands has been reduced significantly (estimated to be at least 10 to 20%) since 1800 through climate change and human activities, particularly by drainage for agriculture and forestry.

- Drainage continue to be the most important factors affecting change in organic peat soils, both globally and locally, particularly in the tropics.

- Human pressures on peat soils are both direct through drainage, land conversion, excavation, inundation and visitor pressure, and indirect, as a result of air pollution, water contamination, water removal, and infrastructure development.

- They are important ecosystems for a wide range of wildlife habitats supporting biological diversity, freshwater quality and hydrological integrity, carbon sequestration, and geochemical and palaeo archives. In addition, they are inextricably linked to social, economic and cultural values important to human communities worldwide.

- Let’s protect our peat and use it responsibly