Peat and Growing Media – An Introduction

What is peat…

Peat is a soft heterogenous mixture of partly decayed plant matter that has accumulated in a water-saturated environment and in the absence of oxygen. A peatland is an area with naturally accumulated peat layer at the surface.

… and peatlands

Peatlands are the most widespread types of wetland in the world and cover more than 4 million square km - that is 3% of the land and freshwater surface of the planet. In these ecosystems are found one third of the world’s soil carbon and 10% of global freshwater resources. Over 90% of peatlands are to be found in the temperate and cold areas of the Northern Hemisphere

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Peatlands are natural systems performing local, regional and often global funcions. They may be considered as land, wetland, geological deposit, natural habitat, grazing meadow or forest. They provide a wide range of wildlife habitats supporting important biological diversity. They also make important contributions to human communities, as they are used, for instance, for agriculture, forestry, fuel production, industry, pollution control, recreation, tourism, nature conservation and scientific research.

How is peat used?

Peat is extracted from peatlands and used principally in horticulture, agriculture, domestic heating and energy generation. Peat extraction includes the drying of wet peat and the collection, transport and storage of the dried product.

Peat has been extracted and used for over two centuries, originally for domestic heating purposes. In Europe, agriculture has been the principal use of peatlands for several centuries, utilizing 125,000 km². Well-managed peatland soils are amongst the most productive agricultural lands available, providing essential food crops

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Peat: a unique substrate in horticulture

Peat offers an ideal substrate for horticultural plant production. Peat forms the basis of growing media that are readily available, easily processed, uniform, high performance and cost-effective.

The horticultural industry in Europe, widely based on peat as the foremost constituent of growing media, is a major economic sector, producing plants, fresh vegetables and fruit for consumers across the continent. The main users countries of horticultural peat in Europe are Belgium, Denmark, Finland, France, Germany, Italy, The Netherlands, Sweden and UK.

The total peat production worldwide is approximately 90 million m³ annually. The share of horticultural peat is approximately 40%. The annual global accumulation of peat exceeds over twenty times the use of peat.

Peat: a valuable local energy source

In several countries, particularly in Ireland and the Nordic and Baltic regions, peat provides an important source of heat and power. As a local fuel, it plays an important role in the decentralized and diversified energy system, providing employment and securing energy supply. Economically speaking, it is a competitive type of energy.

As a fuel it can be used in three forms:

• Sod peat - slabs of peat, cut by hand or by machine, and dried in the air; mostly used as a household fuel;
• Milled peat - granulated peat, produced on a large scale by special machines; used either as a power station fuel or as raw material for briquettes;
• Peat briquettes - small blocks of dried, highly compressed peat; used mainly as a household fuel.

As a fuel, peat is much closer to wood fuels than fossil fuels, which are formed through enormous pressure and require millions of years to form. We therefore define peat as slowly renewable biomass.