RU2302104C2 - Method for complex chemical regeneration and sterilization of soil substitutes - Google Patents

Abstract

FIELD: agriculture, in particular method for regeneration of soil substitute properties.

SUBSTANCE: claimed method includes preliminary elimination of large roots from soil substitutes, basic treatment thereof with 0.2-0.3 % potassium hydroxide solution followed by neutralization with acid weak solution to pH 6.0-6.5. Before treatment with potassium hydroxide soil substitutes are humidified 3-4 times per day with 0.08-0.1 % ammonia aqueous solution for 30-40 days. Sterilization is carried out by damping with 2.0-2.5 % ammonia aqueous solution 2-4 times for 3-5 days.

EFFECT: soil substitutes with decreased population of plant pathogen microorganisms; increased population of advantageous bacterial microflora.

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Description

The invention relates to the field of agriculture and can be used to restore the properties of soil substitutes, long used in modern greenhouse crop production with intensive cultivation of vegetable, flower, decorative and other crops.

Year-round intensive cultivation of plants is associated with a fairly rapid transformation of initially abiogenic soil substitutes into soil-like bodies, which is accompanied by the accumulation in them of products of destruction of plant residues and associated organisms, as well as products of rock destruction, including crushed granite and other mineral materials (Ermakov E.I. and al. Change in crushed granite during the long-term cultivation of wheat and tomato. Soil Science, No. 12, 2000, pp. 1463-1471). The humic acids formed in the substitutes and the complex of water-soluble organic compounds at high concentrations can have a significant negative effect on the productivity and stability of plants (Ermakov EI et al. Accumulation and transformation of organic substances in root-inhabited media. Rosselkhozakademii Vestnik, No. 1, 1996, p. .45-48).

A known method of chemical sterilization and regeneration of soil substitutes, providing for alkaline regeneration and then processing them with a weak solution of mineral acid (USSR Authors Certificate for Invention No. 102143, MKI A01G 31/00, 1974). However, in this case, a sufficiently complete removal of the organic compounds previously accumulated in soil substitutes is difficult due to the non-optimal ratio of carbon and nitrogen (C / N).

For sterilizing soils and substitutes, it is recommended to use formaldehyde and gasification with ethylene oxide in addition to autoclaving and exposure to gamma radiation (Stroetmann J., Kampfer P., Dott W. The efficiency of sterilization methods for different soils. Zentralbl Hyg. Umweltmed, 1994, 195 (2), pp. 111-120). The complexity of the proposed sterilization, the high cost and environmental insecurity limit the possibility of their use.

A known method of sterilization of soils and mineral substrates in low-volume technology using a microwave resonator with a useful volume of 4.8 m ³ and sources of microwave energy - magnetrons (Patent for the invention of the Republic of Belarus, No. 5274, 2003). At the same time, it is required to ensure the extraction of soil substitutes from the places of their use, delivery to the microwave cavity and vice versa, which is associated with large expenditures of physical labor and resources. In addition, this method of sterilization of soil substitutes does not ensure the evacuation of organic compounds from them - products of the destruction of plant residues and related organisms. After a sterilizing effect on soil substitutes, all organic substances remain in them, which serve as a substrate for the subsequent development of numerous microorganisms, primarily phytopathogenic, with all the ensuing consequences.

The closest in technical essence to the claimed method is a method of complex chemical sterilization and regeneration of soil substitutes according to the USSR copyright certificate for invention No. 1021436, MKI A01G 31/00, 1983, which includes the preliminary removal of large roots from them, flooding for 1-2 days with 0.1-0.2% solution of mineral acid, washing with water followed by alkaline treatment with 0.2-0.3% solution of caustic potassium for 2-3 days, washing with water and processing during the day with extracting superphosphate, adjusting p to 6.2 with a mineral acid solution. The USSR author's certificate for invention No. 1303063, MKI A01G 31/00, 1987, additional to it, provides for maintaining them for 20-40 days at a temperature of 25-35 ° C with moistening 2-6 times a day with nutrient solution before flooding the substitutes with a solution of mineral acid .

This method is accepted by us as a prototype.

The disadvantage of the prototype is the incomplete removal of organic compounds that have previously accumulated in soil substitutes due to non-optimal C / N ratios.

The present invention solves the problem of developing a more advanced method of complex chemical regeneration and sterilization of soil substitutes, providing increased productivity and stability of plants, as well as improving the quality of plant products.

Common features of the proposed method with the prototype is the processing of 0.2-0.3% potassium hydroxide solution and neutralization with a weak acid solution to a pH of 6.0-6.5.

The essence of the invention lies in the fact that, in contrast to the known method, including the preliminary removal of large roots from them, an alkaline treatment with a 0.2-0.3% potassium hydroxide solution, followed by neutralization with a weak acid solution to a pH of 6.0-6.5 , in the proposed method, the substitutes are moistened with a solution of 0.08-0.1% aqueous ammonia solution 3-4 times a day for 30-40 days before being treated with caustic potassium solution, and they are sterilized by 2-4 one-time wetting 2.0-2 5% aqueous ammonia solution for 3-5 days.

The technical result achieved by the proposed method is expressed in a decrease in the content of organic matter, a decrease in the number of microorganisms, including phytopathogenic micromycetes, and an increase in the share of useful bacterial microflora in the substitute.

The proposed method is as follows. After the completion of the next vegetation of plants, large roots and other plant residues are removed from soil substitutes. After this operation, soil substitutes are moistened 3-4 times a day with a 0.08-0.10% aqueous ammonia solution to maintain the optimal ratio of carbon and nitrogen (C / N) substitutes, which stimulates the active destructive activity of microflora with respect to previously accumulated organic matter. Treatment with an aqueous solution of ammonia of a lower or higher concentration than in the specified range is impractical, since it does not significantly increase the effect of reducing the content of organic matter. Processing of substitutes with an aqueous solution of ammonia is carried out for 30-40 days and during this time the content of organic matter is significantly reduced in them (table 1). Processing soil substitutes with an aqueous solution of ammonia for less than 30 days is not effective enough to reduce the content of organic matter, and more than 40 days is not economically profitable, since with a greater expenditure of time and money, the treatment result is similar to that observed for 30-40 days.

Table 1 The content of organic matter in crushed granite during composting Duration of composting, day Organic matter content (calculated on carbon),% Prototype The proposed method The concentration of an aqueous solution of ammonia,% 0.05 0.08 0.1 0.5 0 one hundred one hundred one hundred one hundred one hundred 7 68,2 67.9 65.8 65.3 65,2 fifteen 65.9 63.8 60,2 59.1 58.8 25 55.0 53.6 49.8 47.8 47.4 thirty 40,2 37,4 32.9 30.3 29.9 35 36.8 33.8 28.8 27,2 26.9 40 31,2 28.6 23.5 20.7 20.3 45 30.9 28,4 23,2 20,4 19.9

After 30-40-day treatment of the substitute with a 0.08-0.1% aqueous ammonia solution, then with a 0.2-0.3% potassium hydroxide solution, followed by neutralization with a weak acid solution to pH 6.0-6.5, the substitute is sterilized using a 2.0-2.5% aqueous solution of ammonia.

The number of microorganisms, in particular micromycetes, in the soil substitute decreases significantly after treating it with an aqueous solution of ammonia in the concentration range from 0.1 to 2.0% (table 2), which indicates that the amount of organic matter at this time, as follows from the data of table 1, decreased significantly. When treating soil substitutes with an aqueous solution of ammonia at a concentration above 2.0%, the number of micromycetes remains almost at the same level - no more than 6-7 specimens per 1 g of crushed stone. That is why, for the sterilization of soil substitutes, an aqueous solution of ammonia in a concentration of 2.0-2.5% was recommended. The observed effect with respect to microorganisms was most pronounced when the soil was soaked in a 2.0-2.5% aqueous ammonia solution for 3 days or more. An increase in the duration of soaking over 5 days did not cause changes in the number of microorganisms relative to that observed after 3-5 days, which allowed us to recommend this period to achieve the effect of sterilization of the substitute with a 2.0-2.5% aqueous solution of ammonia.

table 2 The number of micromycetes in granite crushed stone of 30 years of use (thousand cells / g of dry crushed stone), depending on the concentration of the sterilizing ammonia solution Type of processing The concentration of an aqueous solution of ammonia,% substitute 0 0.1 0.5 2.0 2,5 5,0 Prototype 3.7 ± 0.4 not processed not processed not processed not processed not processed The proposed method 3.7 ± 0.4 1.8 ± 0.2 0.4 ± 0.05 0.007 ± 0.0006 0.006 ± 0.0004 0.006 ± 0.0005

Treatment with a 0.1% aqueous solution of ammonia of substitutes for 30-40 days, and then alkaline regeneration with a solution of 0.2-0.3% potassium hydroxide and subsequent sterilization of them with a 2.0% solution of ammonia by 2-4 one-time wetting for 3 -5 days compared with the prototype reduces by 259% the content of organic substances (calculated on carbon) in granite crushed stone (table 3).

Generalized indicators of the response of microorganisms to the regeneration and sterilization of crushed granite by the proposed method indicate that after sterilization of the substitute with a 2.0-2.5% ammonia solution, the number and ratio of the main physiological groups of microorganisms is more favorable for plants than after exposure to a 2% formaldehyde solution . The above emphasizes the advantage of the proposed method compared to all previously known methods of regeneration and sterilization of soil substitutes.

The results of the experimental verification of the proposed method are presented in table 4. They indicate that the processing of granite crushed stone by the proposed method increases the biomass of cucumber - Moscow greenhouse hybrid by 46% compared to plant biomass formed after processing granite crushed stone by the method adopted for the prototype.

Table 3 The organic matter content in granite crushed stone of 30 years of use (calculated on carbon) after 30 days of composting Methods of regeneration and sterilization of crushed granite The carbon content, mg / 100 g of crushed stone Source content After composting when wetted with 0.1% ammonia solution and regeneration of crushed stone with a weak solution of potassium hydroxide After processing with 2% ammonia solution Reducing the carbon content in crushed stone after processing with 2% ammonia solution,% Prototype 85.2 ± 6.7 57.8 ± 9.0 Not processed 0 The proposed method 85.2 ± 6.7 46.7 ± 7.0 18.0 ± 6.0 259

Table 4 The effect of complex chemical regeneration and sterilization of crushed granite (2% aqueous ammonia) on the biomass accumulation of 20-day-old cucumber seedlings - Moscow greenhouse hybrid The method of processing soil Raw aerial mass of cucumber plants, g Dry aboveground mass of cucumber plants, g The increase in dry overhead mass,% Prototype 32.65 ± 1.80 2.55 ± 0.40 one hundred The proposed method 42.71 ± 1.95 3.74 ± 0.49 146

The data presented in tables 1-4 confirm the high efficiency of the proposed method for processing soil substitutes in achieving a technical result - reducing the content of physiologically active organic substances, reducing the number of phytopathogenic microflora, stimulating the production process of plants.

Claims (1)

The method of complex chemical regeneration and sterilization of soil substitutes, including preliminary removal of large roots from them, alkaline treatment with 0.2-0.3% potassium hydroxide solution, followed by neutralization with a weak acid solution to pH 6.0-6.5, characterized in that the substitutes Before treatment with a solution of caustic potassium, they are moistened 3-4 times a day with a 0.08-0.1% aqueous ammonia solution for 30-40 days, and they are sterilized by 2-4 single wetting with a 2.0-2.5% aqueous solution ammonia for 3-5 days.