Features of nutrient substrates based on high sphagnum peat

Obtaining high crop yields in greenhouses is impossible without a set of measures to create and maintain optimal physicochemical properties of greenhouse nutrient substrates, which are basic for soil and low-volume technology.

The main component of these substrates is peat, comprising from 30 to 100% by volume. Peat is the best substrate for growing plants. At the same time, it should be borne in mind that peat used for the production of greenhouse substrates should provide optimal conditions for the growth and development of plants. The use of peat and peat substrates with desired properties guarantees the ability to control plant growing processes. However, it is possible to create water and air regimes favorable for plants in the root zone, as well as the desired level of mineral nutrition, taking into account the requirements of the culture, only if certain types of peat are found. It was established that the most suitable for the production of substrates is peat of the upper type of the moss group with a degree of decomposition of not more than 20%, ash content of not more than 5%, and lignin content not more than 5%. The botanical composition should be characterized by the presence of sphagnum mosses in an amount of at least 80% (Kuznetsova L.M., Galaktionova A.A., 1985, Kuznetsova L.M., Bulganina V.N. et al., 1987).

Sphagnum peat peat has significant buffering and high sorption ability. This allows you to apply increased standards of mineral fertilizers and, due to this, to regulate nutrition levels in wide ranges without the risk of creating a salt concentration harmful to plants. This type of peat has antiseptic properties due to the strongly acid reaction of the medium and the presence of phenolic compounds. (Kuznetsova L.M., 1987).

Sphagnum peat, combining high porosity (up to 95%) and high moisture capacity, compares favorably with other types of peat - lowland and transitional. For plant growth on high peat, the optimum moisture content is in the range of 77.7-84.6% by weight. In this case, 35-50% of the pore volume is occupied by air, which is extremely important for the normal functioning of the root system. Even with abundant watering, peat in the pores contains up to 20% of air. Low-level decomposed peat in this regard has less favorable indicators.

Peat peat has optimal water-air, water-retaining, absorption properties, porosity, which creates unique conditions for the root habitat, as well as the rapid growth and development of plants. Organic matter of peat in the process of decomposition produces carbon dioxide, which is important when growing plants in sheltered soil.
It should be noted that horse peat has a stable structure, which for a long time is not amenable to the action of microbiological decomposition. In this regard, this type of peat can be used as soil for three or more years without significant structural changes (Kuznetsova L.M., Galaktionova AA, 1985).
The bulk density of sphagnum peat is small, 130-180 kg / m3. This feature of peat makes it easier to work with it in greenhouses.

The base peat of Pelgorskoye-M LLC, extracted from its own deposits, is represented by low-decomposing high-level sphagnum peat (15%). Peat is light brown, acidic (pHKCl 2.70), low ash (2.51%), with high moisture absorption capacity and high porosity (95%), pure in relation to the content of heavy metals. Peat in terms of quality meets the requirements of GOST R 51213-98, presented to peat of low degree of decomposition. Therefore, peat is suitable for the production of substrates, nutrient mixtures, soils and other peat products.

It is well known that greenhouse soil in the process of many years of use experiences an intense influence of microclimate factors, agricultural technology, etc., in connection with which its physicochemical properties deteriorate, and productivity decreases. The use of low peat decomposition peat for the preparation of nutritious soils (substrates) is preferable in connection with the properties present to this peat, which most closely meet the requirements of the greenhouse culture. Studies on the dynamics of the physical properties of greenhouse soil show that top peat soil retains its structure for three years, loose composition, less fluctuation in the content of organic matter compared to lowland peat soil, which, despite the introduction of organic loosening additives, has significantly compacted . It should be noted that the physical properties of soil from high peat of a low degree of decomposition during operation under production conditions practically does not change under the condition of the annual addition of fresh soil in the amount of 18–20% of the initial volume. An increase in the yield of vegetable crops by 2–4 kg / m2, grown on a substrate from high peat of a low degree of decomposition, in comparison with soils from lowland peat and sod land, was established. The quality of seedlings of vegetable and flower crops was also improved, the growing time of which was reduced, and the survival rate of plants after planting at a constant place was close to 100% (Galaktionova A.A., Kuznetsova L.M., Yakovleva L.N., 1983).