SU1738165A1 - Mineral-fiber substrate for growing plants - Google Patents

Abstract

Use: agriculture for growing greenhouse plants by hydroponic method. SUMMARY OF THE INVENTION: The mineral fiber substrate for growing plants has a corrugated mat impregnated with a hydrophilic substance and whose mineral fibers at the crossing points are bonded with a polymeric binder, and the ratio of the mat thickness to the distance between the tops of the adjacent corrugations is (6-10) :( 4-8 ), at the same time, a layer of glass-fiber sheet was additionally applied on the upper and lower surfaces of the corrugated mat. 6 tabl,

Description

The invention relates to an artificial substitute for soil, namely to a mineral-fiber substrate used as root habitat for growing greenhouse plants by the hydroponic method.

A mineral-fiber substrate is known, made in the form of a pierced corrugated mat with a density of 50-150 kg / m, containing 0.5-3 wt.% Hydrophilic substances. This substrate structure improves the water-physical properties and durability of the material.

However, in the materials of the known invention, only the physicochemical characteristics of the substrate in the initial state are given without taking into account the data on the duration of use of the pierced corrugated mat. Sewing a mat in the absence of a binder leads to the appearance of irregularities on the seating surface. As a result, a defective structure is obtained, which results in deterioration of the agrotechnical parameters of the piercing mat, in particular in terms of capillary absorption ™ (mode of moisture elevation in height) with respect to aqueous nutrient solutions, which ultimately affects the decrease in plant productivity, In addition, repeated use of the pierced mat for growing plants, the need to change crops and the associated removal of root residues leads to the destruction of the substrate surface cover. a (delamination of the material, depressions on the seating surface). The latter makes it difficult to replant and grow plants on a known substrate. These drawbacks of the pierced corrugated mat, arising from repeated use, also lead to an increase in the possibility of salinization, intensive overgrowing of the substrate by blue-green algae, and, as a consequence, the active development of phytopathogenic microflora.

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The purpose of the invention is to stabilize the water-physical properties and improve the phytosanitary state of the substrate during long-term operation.

The goal is achieved by the fact that the mineral fibers of the corrugated mat at the intersection points are bonded with a polymer binder, and the ratio of the thickness of the mat to the distance between the vertices of the adjacent corrugations is (6-10): (4-8), while at the top and The bottom surface of the corrugated mat is additionally coated with a layer of glass fiber cloth.

The fixing of the corrugated substrate structure is achieved, first of all, by the proposed device (construction) of the material — by fixing the pressed corrugated plate between two layers of fiberglass cloth like a skeleton. The latter is due to two effects:

1) the binding of a polymeric substance (phenol alcohol) and a hydrophilizing additive (water-swellable polymer-polyacrylamide of individual mineral fibers in the corrugations;

2) firm fixation of the tops of the corrugations of the substrate with a fiberglass cloth at the top and bottom of the corrugated plate.

If the 1st sign makes a decisive influence in reducing its shrinkage (compressibility), i.e. thickness, then the 2nd sign strengthens the substrate in the longitudinal direction (along the corrugations).

In general, the combination of these features provides a high resistance of the proposed material design with long-term operation on compressive deformation, stretching and bending, which contributes to the stabilization of the water-physical characteristics of the substrate over time, in comparison with the prototype, and, consequently, increasing its durability.

Example. A mineral fiber with a diameter of 3-7 µm obtained from rock melt (basalt, porphyrite, diabase) was used to prepare the substrate. It is characterized by a low content of oxides of alkali and alkaline earth metals (up to 33%), therefore, it retains a high stability when in contact with aqueous solutions of mineral nutrition.

Hydrophilidae additive, in which polyacrylamide was used in an amount of 0.1-0.4 May%, promotes uniform moistening throughout the material and the creation of an effective water-air diet of plants.

At the same time, it performs the function of a polymeric binder.

A glass fiber network or a roll material of randomly arranged staple fibers, in which glass fibers are bonded with a synthetic binder (phenolic or urea formaldehyde, carbamide resin), was used as a fiberglass fiber.

The technological process of manufacturing corrugated mineral fiber substrate plates includes

melting the charge and blowing the mineral fiber by a multi-roll centrifuge into the fiber deposition chamber;

spraying an aqueous solution of a polymeric binder and a hydrophilic substance with the help of nozzles into the fiber deposition chamber;

formation of impregnated mineral carpet on the conveyor;

corrugated mineral wool carpet using a special roller device;

laying on the upper and lower surface of the carpet fiberglass cloth;

compaction and heat treatment at 200-250 ° C of a corrugated carpet in a polymerization chamber;

cutting the carpet into plates and packing in a heat shrinkable polyethylene film.

In tab. Figures 1 and 2 present the characteristics of the structure, composition, and also the water-physical properties of the known and proposed corrugated substrate, taking into account data on the duration of use (for example, the cultivation of leaf beets).

From the data table. 2 shows that the proposed substrate (2-4), in comparison with the material of the prototype (1), is characterized by a higher stability of the structure during its repeated use as a root habitat of plants, as evidenced by high compressive strength and stabilization of water-physical characteristics fibrous material, namely the ratio of pores occupied by water and air, the rate of capillary rise of moisture, as well as density and compressibility, which vary little from the number of growing cycles. However, a known substrate retains its properties only during the first growing season. After the third vegetation, a sharp increase in moisture capacity is observed due to the violation of the structure of the material, and by the period of the fifth vegetation a known substrate almost completely loses its initial strength and water-physical properties,

Corrugated substrates 5 and 6 belong to the control, in which the parameters of design and composition are in the field of extreme values. Moreover, as the substrate 6, a material with a longitudinal layer-by-layer orientation of the fibers, rotated on the edge, i.e. fibrous layers are directed perpendicular to the seating surface (Table 1).

From tab. 2 that material 5 is less characteristic than substrates 2–4, the rate of capillary rise in moisture, as well as an obvious change in the balance in the content of pores occupied by water and air, with repeated cultivation of plants. In contrast, for material 6, due to the high speed of the capillary rise of moisture and the significant moistening of the material, aeration of the root system is difficult.

Evaluation of the effectiveness of using known and proposed substrates was carried out according to seed germination, seedling development, yield of vegetable crops with simultaneous analysis of the phytosanitary condition, the degree of overgrowth of blue-green algae materials, depending on the amount of vegetation and the duration of plant cultivation.

The conditions of the experiments.

The vegetation cycle of vegetable crops was as follows: leaf beet 40 days, pepper 5–6 months, tomatoes 4–5 months (from transplanting to removal of the full harvest). When growing beet, the substrates were subjected to 8-fold, pepper - 5-, and tomatoes - 3-fold use.

The known substrate survived a maximum of five vegetations when growing leaf beets and two vegetations when growing peppers and tomatoes, with a strong destruction of the structure. Therefore, data on the 8th growing season of leaf beets and on the 3rd growing season of peppers and tomatoes on this substrate are not given.

In tab. 3 presents the results of comparative tests of fibrous substrates when growing leaf beets, taking into account the number of vegetation.

Using the example of growing plants of leaf beets, it is shown (Table 3) that when using the proposed substrate, in comparison with the prototype, there is an intensive growth of green mass while improving seed germination. The difference in the compared indicators especially becomes apparent by the period

third vegetation of plants. This is due primarily to the stabilization of the balanced ratio of pores in the proposed material, occupied by water and air. Due to this, the redox processes are activated and the root absorption capacity of plants is increased.

The combination of the above factors has a positive effect on the level of the phytosanitary condition of the substrate.

Thus, phytotoxicity, the degree of overgrowth of the proposed substrate by blue-green algae, as well as the content of phytotoxic microflora is significantly lower than that of the material of the prototype (Table 4.5).

The level of phytosanitary condition, taking into account the amount of vegetation on its leaf beets, is presented in Table four.

The content of phytotoxic microflora in the mineral-fiber substrate under the cover of leaf beets, taking into account the amount of vegetation, is presented in Table. five.

The productivity of vegetable crops grown on fibrous substrates, taking into account the number of vegetation, is presented in Table. 6

Due to the stabilization of the water-physical properties, the high phytosanitary condition of the proposed substrate, as well as the more active absorption of biogenic elements from it, when compared with a known material, an increase in the yield of vegetable crops: tomato and pepper is observed (Table 6), the level of which is maintained during the three growing season. From the data table. 6, it is clear that a known substrate loses its operational properties already by the 2nd vegetation, as evidenced by a sharp decrease in the productivity of vegetables under the conditions of repeated use of the material.

The operational reliability of the proposed substrate was determined: for tomatoes, 12–15 months (3 vegetations, the duration of each vegetation, 4–5 months); for peppers 15–18 months (3 vegetations, the duration of each vegetation 5–6 months); for leaf beets - a representative of green vegetable-vitamin crops - 320 days (10-11 months) (8 vegetations, the duration of each vegetation is 40 days).

In comparison, a known substrate has a maximum duration of vegetation cycles during cultivation: tomato, pepper 2 vegetation (8-12 months); leaf beet 5 growing season (200 days).

Thus, the significant advantages of the proposed corrugated substrate in the form of a plate of a given

designs, in comparison with the famous piercing mat.

Claims (1)

The invention has a mineral fiber substrate for growing plants, having a corrugated mat impregnated with a hydrophilic substance, characterized in that, in order to stabilize the water-physical properties and improve the phytosanitary condition of the substrate during long-term operation, the mineral fibers of the corrugated mat are bonded with polymeric binder at the crossing points, and the ratio of the thickness of the mat to the distance between the vertices of the adjacent corrugations is (6-10) :( 4-8), with the upper and lower surfaces of the corrugated mat being supplemented tionary a layer of fiberglass cloth. Table 1 table 2 Continued tabl, 2 Table 3 Table 4 Table 5 Table 6