In recent decades, the consumption of peat has increased significantly, not only in floriculture for the preparation of garden soil, but also in households. To be able to better assess the arguments "for" and "against" the use of peat, you have to ask yourself: what is peat? Peat is an organic substance, which was formed as a result of the death and incomplete decomposition of peat-forming plants in conditions of excessive humidity and poor air access. Peat was formed in different ways after the glacial period. In the valleys, and, above all, in the depressions of dry lakes, the so-called. low bogs. They were made of reeds, broadleaf cattail, sedge, alder and willow. Plants dying in the water did not decompose completely due to the lack of air and created peat layers rich in organic matter..
Schematic cross-section of a classic raised bog, which was formed from the deposition of peat layers: a - lake silt, b - reed peat, c - peat turzycowy, d - alder and birch-pine peat, e - well-decomposed sphagnum peat, f - poorly decomposed sphagnum peat
Raised bogs were formed on poor sandy soils, in areas with heavy rainfall and high air humidity. Sphagnum moss grew in such conditions (Sphagnum), mud rushes, woolly and other plants that like acidic soil. Every year, the plants that died off formed layers, which are currently in operation. Older peats are darker and more dense, younger - brighter and almost not yet spread out. The peat deposits created in this way have a thickness of 10-12 m.
The properties of peat depend on the conditions, what acted on the peat bog: type of substrate (from the bottom) and lights, air and heat (from the top). Peat has an insulating and preservative effect, Therefore, it inhibits the processes of circulation and exchange of matter between the soil, plants and the entire surroundings. Therefore, it cannot significantly improve the properties of the soil, but it can be used to protect the soil from external influences and keep it moist. How can these properties of peat be used?? Its suitability for the preparation of special horticultural soil for the cultivation of potted plants has already been mentioned (especially azaleas and briar) and for the production of seedlings. In the cultivation of rhododendrons, azalii, highbush blueberry and other acidophilic plants on alkaline or neutral soils (especially in the south of Germany) the addition of acid peat to the soil is necessary. The addition of peat to sandy and gravely soils significantly improves their water relations and accelerates the process of humus formation. Many gardeners use peat to loosen heavy soils, especially if they have not been cultivated so far, although the same or even better effect could be achieved by growing legumes. It must be emphasized, that for biodynamic horticulture only peat can be used without any mineral additives, the so-called. non-de-acidified peat. Peat can also be added to compost and used to store biodynamic preparations as a material that insulates them from external influences. Unlike other sources of caries, peat is not a fertilizer, though with time, with sufficient air and water access, it decomposes very slowly. As a result of this process, the elements contained in it are transformed into forms available to plants. However, it takes a long time, because peat is incorporated very slowly into soil processes.