Peat is an organic matter of the Quaternary age, most often Holocene. It is an accumulation of partially decayed vegetation. The process of its origin of peat requires high groundwater level and acidic and anaerobic conditions which inhibit decay of plant material.
According to genetic features there are three types of peat distinguished: low, high and medium. The richest in food ingredients is low peat occurring in river valleys and lake edges.
Geological and quality criteria which define a peat deposit are: - thickness of deposit not smaller than 1 m; - maximum ratio of overburden thickness to mineral deposit - 0,5; - maximum ash content - 30 %. There are several quality parameters deciding on peat use:
- grade of decomposition (according to von Post: H1 – not decomposed; H10 - totally decomposed),
- ash content (organic matter content in 100 g of dry mass),
- bacteriological valuation (coli titer).
Peat is used in gardening and in agriculture as organic fertilizer and a medium added to a soil to improve its physical properties. It is also used in balneology (peat baths and poultices and mud wraps), medicine and therapeutics. Peat is no longer used as a fuel in Poland. Peats used in medicine are therapeutical muds which have to be clean microbiologically, with high content of active organic compounds, advanced decay of organic matter, smooth mud consistency, moisture content over 75 % and should not be affected by freezing and defreezing.
Peatlands are found mainly in northern part of Poland (about 70 %). They cover an area of about 1.2 million hectares (around 4.2 % of area of the country) and their volume is estimated at over 17 billion m3. Up to the present, almost 50,000 peatlands have been catalogued by the Institute for Land Reclamation and Grassland Farming. According to these records, about 18 thousand of the catalogued peatlands form a potential resource basis for peat harvesting. These peatlands are without any special importance from the point of view of nature protection.
There are most important peat deposits (with muds marked out) presented on the map.
In 2011, anticipated resources of peat were estimated at 74.18 million tonnes, decreasing by about 2.14 million tonnes in relation to the previous year. Decrease of the resources is mainly the result of crossing out three deposits of the resources amounted to 267 thousand m3.
Table 1 shows resources and the current state of exploration and development of peat deposits.
The output of peat amounted to 1,214 thousand m3 in 2011 and increased by 229 thousand m3 (23 %).
There were 11 new deposits documented in 2011 – seven of them in wielkopolskie voivodeship – with anticipated economic resources of 520 thousand m3.
Prepared by: Agnieszka Wałkuska