Selecting a peatland
The process of selecting a peatland to harvest peat moss is greatly facilitated where detailed surveys of the resource exist. Factors to consider include:
- Quality of the peat: it must meet market standard. In Canada and the U.S., light brown, weakly decomposed sphagnum peat moss is preferred by professional users such as greenhouse growers. More decomposed, dark brown peat moss is generally used in horticultural mixtures aimed at amateur gardeners.
- Peat depth: the thickness of the horticultural grade peat layer must be sufficient to warrant development. An average depth of 2 m is generally considered to be a minimum.
- Surface area: a peatland must be large enough to warrant development. An area of 50 ha is usually required, although smaller sites are occasionally developed.
- Other factors such as: proximity to transportation infrastructure (roads, truck access), a low density of tree cover, availability of a labour force, access to electrical power also play a decisive role in peatland selection.
Peat moss harvesting
Ensuring proper drainage
A main drainage ditch is dug along the perimeter of the peatland to drain water. Shallow ditches are dug parallel to one another to lower the water content in the peat to about 85 %. These secondary ditches drain into the main peripheral ditch.
Removing surface vegetation
Using a rotovator, the surface vegetation is removed to expose the underlying peat. The live plant fragments can be collected and used to restore former peat harvesting fields.
Levelling and crowning the harvest fields
A screw leveller is used to even the ground surface and to profile the harvest fields in a convex fashion in order to improve drainage of surface runoff.
The surface is milled and harrowed with various pieces of equipment to loosen the peat and accelerate the drying process that depend on the sun and favourable wind conditions.
Harvesting the peat
After a few days of drying weather, the water content of the surface peat layer is reduced to about 50 % and it is ready to be harvested. It is collected using large vacuum harvesters or other suitable equipment.
The peat is transported to a processing facility to be screened in various grades and packaged. Special growing mixes can be produced by incorporating other ingredients such as compost, coir, bark or fertilizers.
Transporting the peat
Peat is now ready for shipping. It is transported in the form of compressed bales of various sizes, to be used by professional horticultural producers, greenhouse and nursery growers, and by everyday consumers in department stores and garden centres.