IS PEAT MOSS ORGANIC?
Sphagnum peat is high in organic matter,
which can be used to improve the structure of soil.
Peat consists of 95 % organic material. It is a mixture of decomposed plant material that has accumulated in a water-saturated environment without oxygen. Sphagnum moss is one of the most common plant species found in peat bogs. Peat, which is extracted from bogs dominated by this group of species, is often described as Sphagnum peat. Sphagnum peat therefore, mainly contains decomposed Sphagnum moss.
Sphagnum peat decomposes slowly over several years compared to other types of organic matter such as compost, that decompose within one year.
GROWING MEDIUM PURITY
The peat is a very clean medium that has no weeds or pathogens inside.
Peat is produced in remote areas where there is no commercial crop production activity, so it does not contain weeds or other contaminants and it is naturally free of human and plant pathogens, parasitic nematodes, pests and fungi of cultivated plants. In addition, during winters temperatures can dive to below -25 ⁰C which helps to kill unwanted pathogens.
Peat contains beneficial microbes which help to prevent fungal diseases.The naturally occurring humic acids stimulate root growth. It is 100% and as it is an organic material it is also compostable and does not produce unwanted waste.
Pore volume indicates a soil’s ability to hold water and air. Sphagnum peat has a pore volume of more than 95%, which makes it an excellent material for potting mixes and soil improvement. Fine sand has about 45% total porosity, while a clay loam has about 60%.
Peat is an organic material with low bulk density, particle density, and high porosity. Particle density is relatively low, usually ranging from 1.0 to 1.6. The total porosity in the peat reaches up to 80–90% and even a bit more due to dominantly low bulk density values despite less particle density. As the peat particle size distribution increases, water retention capacity decreases and the aeration volume increases. The results of many studies showed that peat provided high macropore volumes (45–50%) and also greater water volumes (40–45%) at low tensions (<1 kPa). Mixed mediums containing peat have more water holding capacity in the root zone and create a more aerated environment.
Peat has comfortable storage conditions and very economical to buy.
Many peat-free media may incur problems during storage. The principal polymer in peat is lignin, which is resistant to microbial degradation. Coir also contains a high proportion of lignin, but materials such as bark, timber waste, wood fires and paper waste have a high cellulose and hemicellulose content, and microorganisms readily degrade these polysaccharides. Structural breakdown of materials may occur, and microbial growth may lead to utilisation of nutrients- especially nitrogen – added to media. Furthermore, the appearance of microbial growth in bagged media is unsightly and may deter consumers.
Peat contains naturally occurring microorganisms. These natural microorganisms will continue to be active in the substrate after production, which is perfectly normal. Some natural microorganisms are antagonistic against fungal diseases and may help to produce healthy and strong plants.
Peat products should be taken into use during the three months after the customer has received the products. The best place for storing peat products is a cool, dry and dark storage area. Peat products are sensitive to direct sunlight. High temperature accelerates the action of microbes and induces the loss of nitrogen. High humidity can cause problems with moulds. Peat products should be isolated from any form of potential contamination by plant diseases.
In general, approximately 80–90% of a fresh peat is composed of water and the remaining of solid material. The solid material has most of the components as organic and only 2–10% as inorganic.
Peat media are usually fertilised with straight inorganic nutrients and the only change that may occur in storage is a slow rise in pH from dissolution of calcium and magnesium added as chalk or dolomitic limestone.
Natural peat straight from the bog has a low pH of around 3.5 to 4.5. The consistently low pH allows growing media manufacturers to adjust the pH of the peat substrate depending on the needs of the current crop. Most commercial horticultural crops prefer a slightly acidic substrate. Usually calcium carbonate is added to adjust the pH of commercial growing media to be between 5.5 and 6.
Peat has a low electric conductivity (EC) which makes it easily adjustable. EC is an expression of the amount of salts in a solution. Low EC illustrates that there are very little available nutrients, or other salts – which can even cause phytotoxic effects such as sodium or chloride ions. This ‘blank canvas’ allows the substrate producer to enrich the peat with specific starter fertilisers. The possibility to adjust the amount of specific nutrients accurately is important, because the need for fertilising depends on the type of crops and stage of growth.
Peat has a high cation exchange capacity (CEC). The CEC refers to the ability to attract, retain and exchange cations such as potassium and calcium ions. A high CEC allows a reservoir of nutrients to be held within the substrate and not flushed out during irrigation. These retained nutrients slowly replenish those removed from the substrate by plant uptake.
Peat enables the media for several applications with its low pH and nutrient content. It has an important structural characteristic that is long constant even under intensive use and it is biodegradable.
Several obstacles like cost, quality and technical problems provide high proportion usage of peat in media.