Majority of soilless growing media are made with a base of sphagnum peat moss
Harvesting – open field processing
Peat harvest have using two different methods: block cutting and vacuum harvesting (milled peat).
Dredging (wet excavation) sod peat. The process is based on the extraction of peat using two methods -with a excavator or with a bucket excavator. Using this technique, peat can be obtained at the depth of the entire developed deposit. The method of extracting peat is used to obtain a natural structure. Peat blocks are cut with a mechanized cutter and left on the bog. Through the summer, the blocks are turned upside down for even drying. That is manual work and explain sod peat higher price. Then blocks are picked up and placed in stock piles. From the stock piles the blocks are transported to the factory for further processing.
Block peat is used in high-quality premium class substrates.
Vacuum harvesting is a method where the upper 2-3 cm of the bog is milled, and after drying the peat is gathered by using a vacuum harvester. Milled peat characterized by a variety of two particle sizes ranging from 0-6 mm to 26-60 mm. The task of milling the peat mill is to get out of the mud crushed peat crumb, which is the fastest way to die. Milling depth is regulated depending on the amount of drying of the field in relation to the theoretical conditions and characteristics of peat deposits. Average milling the depth is 12-15 mm.
This method results in peat with a greater proportion of fine particles than block peat.
Then raw materials are transported by truck from the peat bog to the factory stock area.
Peat processing in the factory
All white peat raw materials are processed in the factory before they are used for the final substrate. All raw materials have to meet a technical specification in terms of structure, moisture content and weight. The use of star screens ensures a very gentle processing of the peat raw materials. Different grades of white peat raw material are achieved using this common procedure.
Black peat raw materials need to be processed using specific milling technologies. Black peat is screened depending on its intended use.
During the screening process of white peat, the peat fibres remain on the screen as a raw material. They are separated from the screened peat and are cut into 25 mm and 60 mm lengths. These are two other important raw materials for medium as well as coarse potting and container substrates since they provide aeration and water transport capabilities.
The production of a substrate
The mixing lines are partially computer controlled. Filling capacities as well as fresh weight of raw materials and substrates are controlled continuously throughout the production process. After finishing the production process, each batch is controlled in own on site laboratories according the respective product specification.
1. Screening – screens and cutters. Peat is transported to the screening lines. Once shredded, the peat passes over a number of “star-wheel” screens. The coarsest peat is carried over to the “cutters”, where it is cut into smaller pieces. Standard screening grades are : 0-7, 0-10, 0-20, 0-40, 7-15, 15-30, 25-40 and above 40 mm.
2. Raw material filled in special hoppers. For the production of substrates the required peat quality is transported to the mixing line.
3. Full control of production in real time, each substrate has its specific recipe filed.
4. Peat raw materials and constituents are carefully dosed in controlled ratios onto the transportation belt.
5. Limestone, fertilizers and other additives are supplied automatically from hoppers. Then weighing hoppers do exact dosing of additives.
6. Mixing drum for final blend
7. Filling of bags or bales. In the packing hall the products may be packed into big bags, compressed 250 litre bales or loose-filled 80 litre bags.
8. Production in time and delivery to minimise storage
Outturn is measured according to the European norm EN12580.
The samples from final substrates are always taken from the production lines and sent to internal laboratory for immediate analysis. Laboratory carry out controls on all manufactured products prior to delivery:
- Distribution of particle size
We make screenings in the laboratory to know the distribution of particles, from the finest fraction (0-1 mm) to the coarsest fibres and lumps. Each product has its own standard in order to ensure uniform structure from one delivery to another.
- Water uptake
A samples of the substrate is put in a pot, and its ability to take up water is measured in an ebb and flood system. It is important that the substrate takes up water immediately when first irrigation is made in the nursery.
- pH and conductivity
Adjustment of pH with lime and addition of fertilizer is controlled by measuring pH and conductivity in each production batch as soon as the production is made.
- Drain capacity and water-holding capacity
We have set standards for these characteristics for each type and screening of peat. Correct water/air ratio has significant influence on plant performance.
Certified raw materials for substrates
Raw materials are continuously tested by State Agency for suitability before their use in substrate production. We also conduct our own vegetation trials to ensure the physical, chemical and biological properties of growing media.
Free of contamination
All substrates are subject to stringent hygiene measures and are tested for pests and diseases, heavy metals, radioactivity, human pathogens and nematodes. Based on these regular internal and independent external controls, we are able to declare that our substrates are free from plant pathogenic diseases (e. g. Rhizoctonia, Pythium, Phytophthora, Thielaviopsis, Fusarium species, others) and free from plant pathogenic nematodes as well as human pathogens. Substrates almost free from weeds.