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Agrochemistry

Characteristics and composition of Seliger Agro specialized soil.

For students

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AGROCHEMISTRY A

Biological activity and the basis for professional soil

Specialized substrates allow for precise control of mineral nutrition of plants in greenhouses and nurseries. "Seliger-Agro" soils are based on natural peat, which provides optimal porosity and water-holding capacity in the root zone. Thanks to this, the root system receives sufficient oxygen, and irrigation water is distributed evenly without stagnant waterlogging.

  • Humus content in the peat base — up to 80 %
  • Minimum acidity (pH) — 4.2
  • Maximum acidity (pH) — 6.5
  • Maximum nitrogen content — 1065 mg/l

The main technological feature of these substrates is high biological activity. During the production process, beneficial microflora is introduced into the soil, which activates microbiological processes directly in the root zone. This accelerates the mineralization of organic compounds and the conversion of nutrients into forms easily accessible to plants.

All soils in the product line are fully ready for use, contain a starter complex of nutrients, and do not require additional application of liming materials before planting.

Substrate specialization by crop type

Each group of crops has its own requirements for pH levels and nutrient concentration. The product line includes both universal compositions for a wide range of plants and highly specialized soils. The features of key mixtures are given below:

  • "EXO" — a universal soil based on high-moor peat of medium decomposition, mixed with organic-mineral fertilizers and lime. Suitable for seed germination, growing transplants of vegetable and fruit crops, flowers, as well as for improving soil structure, mulching, and lawn restoration.
  • "For flowers and houseplants" — an air-permeable substrate based on deacidified high-moor peat with sand, intended for growing houseplants and flowers in open soil.
  • "For azalea and heather" — an acidic substrate made of moss and fen peat with sand and limestone. Developed for plants with low nutrient requirements but sensitive to acidity: azaleas, rhododendrons, heather, blueberries, cranberries, geraniums, blue hydrangeas, and philodendrons.
  • "For begonia and rose" — a mixture of loosened high-moor and fen peat with sand and lime for crops with medium nutrient requirements. Used for growing roses, begonias, gloxinias, kohlerias, tradescantias, as well as transplants of perpetual carnations, geraniums, chrysanthemums, and cyclamens.
  • "For saintpaulia and cyclamen" — high-nutrient soil for nutrient-demanding bedding, balcony, and pot flowers (saintpaulias, cyclamens, gerberas, red hydrangeas, New Guinea impatiens, chrysanthemums).
  • "For desert cacti" — a porous substrate of deacidified peat, river sand, and expanded clay sand. Intended for Aporocactus, Cleistocactus, Myrtillocactus, Notocactus, Ferocactus, Chamaecereus, Echinocactus, Gymnocalycium, Lobivia, Mammillaria, Opuntia, Parodia, Rebutia, and Echinopsis.
  • "For forest cacti" — a loose mixture of fen and high-moor peat with river and expanded clay sand, calcium, and nutrients for the Christmas cactus (Schlumbergera truncata), Rhipsalis, Rhipsalidopsis, and Epiphyllum.

Detailed chemical composition and acidity levels of the specialized soils are shown in the table.

Soil name Nitrogen (N), mg/l Phosphorus (P), mg/l Potassium (K), mg/l Microelements pH
Last Duty 100–200 100–200 150–280 no 5.5–6.5
For yucca and dracaena 125–225 125–225 185–335 yes 5.0–6.0
For citrus 210–390 210–390 320–560 yes 5.0–6.0
For ficus 190–350 190–350 280–520 yes 5.0–6.0
For palms 175–325 175–325 260–480 yes 5.0–6.0
For succulents 55–105 55–105 80–150 yes 5.0–6.0
For forest cacti 70–130 70–130 105–185 yes 5.0–6.0
For desert cacti 50–90 50–90 75–135 yes 5.0–6.0
For saintpaulia and cyclamen 210–390 240–440 260–490 yes 5.5–6.5
For begonia and rose 140–260 160–300 180–380 yes 5.5–6.5
For azalea and heather 60–120 60–120 120–240 yes 4.2–4.5
For flowers and house plants 100–200 100–200 140–260 yes 5.5–6.0
Strawberry 200–320 220–440 225–415 yes 5.6–6.5
Cabbage 575–1065 385–715 255–475 yes 5.5–6.5
Lawn 65–125 170–310 70–130 yes 5.5–6.0
Cucumber 130–250 250–450 280–520 yes 5.6–6.3
Tomato and pepper 180–320 350–650 350–650 no 5.6–6.0
EXO 100–180 135–255 115–215 no 5.5–6.0

"Seliger Agro" formulations for indoor and greenhouse crops

When growing potted crops in greenhouse conditions, the water-physical structure of the substrate and the balance of nutrients play a key role. Specialized "Seliger Agro" soils are created taking into account the requirements of specific plant groups regarding drainage levels and acidity. A mixture of fen and high-moor peat combined with river sand and expanded clay provides an optimal air regime for the root system.

The starter supply of macronutrients in these soils is precisely dosed, which eliminates the risk of salt stress during transplanting. An agronomist can select a substrate with the necessary pH level and nutrient concentration for a specific crop, based on the provided physical and chemical indicators.

Soil brand Target crops Base composition pH N, mg/l P, mg/l K, mg/l
For succulents Agave, aloe, Bryophyllum, Gasteria, Orostachys, Kalanchoe, Cotyledon, Senecio, Sempervivum, Euphorbia, Sedum, Crassula, Faucaria, Haworthia, Ceropegia, Echeveria, etc. Fen and high-moor peat, expanded clay and river sand, ground limestone, macro- and micro-fertilizers 5–6 55–105 55–105 80–150
For palms Coconut, date palm, Howea, Sabal, Washingtonia, Jubaea, Chamaedorea, sago, fan palms, and other palm species Fen and high-moor peat, expanded clay gravel, river sand, lime, and complex fertilizer 5–6 175–325 175–325 260–480
For ficus Rubber fig, Benjamin fig, fiddle-leaf fig, Banyan fig, Mistletoe fig, rusty fig, sacred fig, etc. Fen and high-moor peat, expanded clay gravel, river sand, lime, and complex fertilizer 5–6 190–350 190–350 280–520
For citrus Orange, grapefruit, kumquat, lemon, mandarin, citron, etc. Fen and high-moor peat, expanded clay gravel, river sand, lime, and complex fertilizer 5–6 210–390 210–390 320–560
For yucca and dracaena Yucca, Nolina, Cordyline, Dracaena, and others (false palms) Fen and high-moor peat, expanded clay and river sand, ground limestone, macro- and micro-fertilizers 5–6 125–225 125–225 185–335

Specialized and universal Fasco soils

For large-scale production of transplants and container crops, Fasco offers ready-to-use peat-based soils. These substrates contain sand, liming materials for pH neutralization, and a full complex of nutrients in an easily accessible form. Chlorine-free mineral fertilizers in the formulations prevent salt burn of the root system in young plants.

Light-shielding layer: the polyethylene packaging of Fasco soils has an inner black layer. It blocks ultraviolet and visible light, preventing the development of blue-green algae and other light-loving microorganisms during storage.

In addition to the specialized "Gloria" brand for roses, the manufacturer produces soils with a similar composition and concentration of nutrients for azaleas, begonias, bulbous plants, ferns, citrus, African violets, ficus, as well as the "Oasis" and "Tropic" series. Products in this group differ only in pH level, which is selected according to the physiological requirements of the plants. The main characteristics of professional brands are presented in the table.

Soil brand Purpose and crops Base composition pH N, mg/kg P, mg/kg K, mg/kg
Gloria Growing any types of roses Transitional peat, sand, expanded clay, lime, chlorine-free nitroammophoska 6.0–6.5 150–350 250–400 250–400
Soil for your favorite plants Garden and indoor plants: roses, peonies, clematis, ornamental and berry shrubs, conifers, ferns and asparagus, palms and citrus, begonias, aglaonema, yucca, dracaena, cordyline and sansevieria, monstera, schefflera, fatsia, ficus, ivies and vines Transitional peat, sand, expanded clay drainage, nitroammophoska, limestone flour 6.0–6.5 150–350 250–400 250–400
Krepysh Indoor flowers, transplants of tomatoes, peppers, cucumbers, zucchini, cabbage, eggplant, physalis, winter garden on the windowsill (green onions, lettuce, spicy herbs), transplanting seedlings into pots and open ground Transitional peat, sand, expanded clay drainage, lime, chlorine-free nitroammophoska 6.0–6.5 250–300 200–300 300–400
Malyshok Growing transplants and adult plants of nightshade crops (tomatoes, eggplant, peppers) Transitional peat, sand, expanded clay drainage, lime, chlorine-free nitroammophoska 5.0–5.5 60±10 190±40 80±20
Ogorodnik Growing fruit, berry and flower crops, vegetable and indoor plant transplants, winter garden on the windowsill, lawns in open and closed ground Sphagnum and lowland peat, sand, lime, drainage, complete mineral fertilizer 6.0 275 250 350

Please pay attention to the composition of the "Malyshok" soil. Due to its lower acidity (pH 5.0–5.5) and specific nutrient ratio (low nitrogen content of 60±10 mg/kg and potassium of 80±20 mg/kg), this substrate is intended strictly for nightshade crops. Using it for other plant types may lead to stunted growth and nutrient deficiency.

  • Acidity of "Malyshok" substrate — 5.0–5.5 pH
  • Nitrogen in "Krepysh" soil — 250–300 mg/kg
  • Potassium in "Ogorodnik" soil — 350 mg/kg
  • Phosphorus in "Gloria" soil — 250–400 mg/kg

For closed ground and transplant production, the quality of soil mixtures is of critical importance. Specialized "Sadovnik" and "Tsvetochny" soils provide plants with a balanced start, supplying them with accessible macro- and microelements during the early stages of the growing season.

"Sadovnik" soil is a universal ready-to-use substrate based on sphagnum and lowland peat, sand, and drainage. It is neutralized with lime and amended with a complete mineral fertilizer. The mixture is used for growing and transplanting seedlings, when planting crops in open ground, and also for earthing up the stems of cucumbers, tomatoes, and peppers.

"Tsvetochny" soil is designed as a multi-purpose, well-aerated substrate. Its composition includes transitional peat, sand, expanded clay drainage, limestone flour, and nitroammophoska. It is optimal for growing flower transplants, indoor plants (African violets, geraniums, ivy, pachystachys, chlorophytum, cyperus, monstera, euonymus, fatsia) and forcing bulbous crops (tulips, crocuses, hyacinths, daffodils, irises).

Soil brand Nitrogen (N), mg/kg Phosphorus (P), mg/kg Potassium (K), mg/kg Acidity (pH)
Sadovnik 150–300 200–400 300–450 5.5–6.5
Tsvetochny 150–350 250–400 250–400 5.5–6.5

Substrates are used both in dry form and for preparing liquid top dressing. For dry application, 3–7 g of soil per plant is added to planting trays. For liquid top dressing, an aqueous solution is prepared: 50–100 g of soil is mixed with 2–4 liters of water, left to infuse for 2–3 hours, and used to irrigate the transplants twice a month.

To improve the structure of soil mixtures, vermiculite is used—a lightweight flaky additive obtained by firing low-grade mica at temperatures exceeding 800 °C. During use, vermiculite gradually releases potassium and magnesium into the soil solution and also adsorbs excess salts, preventing acidification, mold development, and soil compaction.

Vermiculite has low durability. Over time, its structure becomes clogged with root exudates, and the material begins to accumulate pathogenic microflora.

  • Increase in soil service life — 2–3 times
  • Extension of fertilizer effect — 1.5–2 times
  • Raw material firing temperature — more than 800 °C
  • Application rate for mulching — 5–6 l/m²
  • Application in the planting hole for potatoes — 30–60 g
Element in vermiculite composition Content, %
Silicon 38–45
Aluminum 10–16
Iron 6–13
Potassium 1–6
Calcium 1–5

The sorbent is incorporated into crop cultivation technology according to the following schemes:

  • Preparation of mixture for vegetable and flower transplants: vermiculite is mixed with soil in a 1:4 ratio.
  • Rooting of cuttings: use a mixture of vermiculite and peat in a 1:1 proportion.
  • Mulching of tree rings for fruit and berry crops.
  • Potato planting locally in the hole.
  • Application together with dry mineral fertilizers in a 1:3 ratio.

Chemical amelioration of acidic and alkaline soils

In field conditions, agronomists often have to deal with soils that have an unfavorable pH level. Acidic sod-podzolic soils and alkaline solonetz soils possess poor physicochemical properties, which hinders the uptake of nutrients and reduces overall yield. Chemical amelioration allows for a radical improvement of these indicators.

Amelioration does not just temporarily correct the medium's reaction but removes toxic salts from the root zone and reduces the share of adsorbed sodium or hydrogen.

The choice of ameliorant directly depends on the type of soil adsorption complex:

  • Acidic soils are improved by the liming method, neutralizing excess hydrogen.
  • Alkaline soils and solonetz require gypsum application to displace excess sodium from the soil adsorption complex.

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