RU2616674C2 - Method for improving soil structure - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method involves the preliminary application of the structure-forming additive - nanobentonite in the amount of 15.0-25.0 kg per 1 ha of sown area - onto the soil surface, plowing, harrowing, and the cultivation.

EFFECT: increasing the proportion of the particles ensuring soil fertility, the soil structuring factor, and water stability.

1 tbl, 12 ex

Description

The invention relates to the field of preparation of soil cover for growing various crops and can be used in agriculture.

There is a method of improving the structure of the soil by pre-applying to its surface a structure-forming additive - ethoxylated polyoxyethylene glycol, plowing, harrowing and cultivation [1]. The disadvantage of this method is the relatively low proportion of those soil particles that make a decisive contribution to its fertility, namely with a size of (0.25-10.0) mm, as well as a low structural coefficient. In addition, the organic preparation that appears in it may not be completely processed in the soil over time and accumulate in it, thereby creating undesirable consequences for growing crops.

There is also a method of improving the structure of the soil by preliminary applying to its surface a structure-forming additive - bentonite, plowing, harrowing and cultivation [2]. The disadvantage of this method, which, in terms of the combination of operations and the technical effect achieved by using it, is the closest to the object claimed by the authors and therefore taken by the authors as a prototype, is also the relatively low proportion of those soil particles that make a decisive contribution to its fertility, namely, the size (0.25-10.0) mm, as well as relatively low structural and water strength factors.

The purpose of the present invention is to increase the proportion of those soil particles that make a decisive contribution to its fertility, namely with a size of (0.25-10.0) mm, as well as an increase in the structural and water resistance factors.

The declared goal is achieved by the fact that in the known method of improving the soil structure by first applying a structure-forming additive, plowing, harrowing and cultivation on its surface [2], nanobentonite is used as a structure-forming additive, which is applied to the soil surface in an amount of (15.0-25.0) kg on 1 ha of sown area. As a result of using the inventive method, the proportion of particles providing soil fertility increases by 20-25%, the structural coefficient is 40-50%, the water resistance coefficient is almost double compared to those for the prototype method [2].

Until now, the literature has not described any way to improve the structure of the soil, in which nanobentonite or another natural mineral with a nanostructured level of organization of matter would be used as a structure-forming additive. This circumstance allows the authors to argue that the claimed object meets the first of the criteria established by the legislation of the Russian Federation for the invention — novelty. A comparison of the known features of the prototype method [2] and the distinguishing features characterizing the object claimed by the authors (replacement of the structure-forming additive used in the prototype — natural bentonite containing micro and macro particles with sizes of the order of 1 μm or more, by nanobentonite containing nanoparticles with sizes less than 100 nm), does not allow to predict a priori the appearance of new properties in comparison with the prototype, namely, an increase in the proportion of particles ensuring soil fertility, structural coefficient and water resistance awns. This circumstance gives the authors every reason to argue that the claimed object does not explicitly follow from the level well-known in the art and, therefore, corresponds to the second criterion feature of the invention — inventive step. The proposed structure-forming additive is very simple in composition, the preparation of both itself and the nanobentonite used in it is quite easily feasible on an industrial scale and, therefore, its practical use is also feasible without any problems; therefore, the claimed object corresponds to the third criterion feature of the invention - industrial applicability.

The use of the inventive method can be represented by the following examples.

Example 1 (preparation of additives)

Natural bentonite from the Tarn-Var deposit (Nurlat district of the Republic of Tatarstan) is ground into flour and mixed with distilled or deionized (desalted) water at the rate of 20 g of bentonite per 100 ml of water. The resulting mixture is treated with ultrasound in an ultrasonic disperser UZU-0.25 with a power of 80 W at a frequency of 18.5 kHz with an oscillation amplitude of an ultrasonic waveguide of 5 μm for (5-20) minutes at room temperature, resulting in a water-bentonite suspension with bentonite particle sizes from 5 to 100 nm. The suspension of nanobentonite thus prepared is then used as an additive to the soil.

Example 2

The structure-forming additive specified in Example 1 is applied to the soil surface — nanobentonite in the form of a suspension at the rate of 75 l (i.e. 15 kg of nanobentonite) per 1 ha of cultivated area, after which it is plowed, harrowed and cultivated using a traditional method. Then, the content of aggregates of a certain size is determined by the so-called method. “Dry” aggregate analysis, and water-resistant aggregates - by the so-called method. “Wet” aggregate analysis in accordance with the method described in [3]. In the framework of the first of these methods, a sample of 1 kg is taken from a sample of the air-dried soil prepared above, sieved in portions through a sieve column with a diameter of 10, 7, 5, 3, 2, 1, 0.5, and 0.25 mm, avoiding with strong shaking. As a result of this procedure, the soil is divided into fractions with particle sizes> 10, 10-7, 7-5, 5-3, 3-2, 2-1, 1-0.5, 0.5-0.25 and <0 , 25 mm. Each fraction is weighed on a technochemical balance and its mass fraction is calculated as a percentage of the mass of the soil sample taken for analysis. In the framework of the second method, an average weight of 50 g is collected from individual fractions of aggregates obtained by dry sieving, for which a weight in g of numerically equal to half the percentage of this fraction in the soil is taken from each fraction on a technological chemical balance. Moreover, the fraction with a particle size <0.25 mm is not included in the average sample, so as not to clog the lower sieves during sieving. Next, they make up a set of 6 screens with holes from 5 to 3, 2, 1, 0.5, and 0.25 mm in diameter from the top to the bottom, fasten them and place them in a water tank so that there is a layer of water above the side of the top screen 5-6 cm. A cylinder with a sample of soil is filled with water for 2/3 of the volume and left to stand for 10 minutes, after which it is added to the top with water. After that, it is covered with a watch glass, tilted to a horizontal position and placed vertically. This procedure is repeated twice until the air is completely removed from the soil. Then the cylinder is closed with a stopper and kept in this position until the bulk of the soil aggregates fall down, after which it is turned over and waiting until the soil reaches the bottom. The described process is repeated 10 times until the destruction of fragile aggregates. Then, the bottom to the top of the cylinder is transferred to a set of screens and open the cylinder plug under water. The soil transferred to the sieve is sieved under water: a set of sieves is lifted under water without exposing soil clumps on the upper sieve, and lowered down with a quick movement. After 2-3 seconds, the movements are repeated. After 10 shakes, remove the top two sieves and continue to shake the bottom three sieves five more times. The aggregates remaining on the sieves are washed off with a stream of water from the wash bowl into large porcelain cups. After the soil aggregates have settled to the bottom of the cups, excess water is carefully drained from the cups and the soil aggregates are transferred to pre-weighed small porcelain cups for drying in a water bath to an air-dry state, and then weighed on a technical balance. The mass of each fraction of aggregates in grams is multiplied by 2 (since the calculation is made per 100 g of soil, and 50 are taken for analysis) and the percentage of water-resistant aggregates in the soil is obtained. The content of the fraction less than 0.25 mm is determined by the difference: 100% - Σ of all fractions> 0.25 mm, in%. The results for determining the proportion of particles ensuring soil fertility, namely with sizes in the range (0.25-10.0 mm), as well as structural and water strength factors for this case are presented in Table 1.

Example 3

Perform, as Example 2, but with the introduction specified in Example 1 suspension of nanobentonite at the rate of 20.0 kg of nanobentonite (i.e. 100 l of this suspension) per 1 ha of sown area. Data for determining the proportion of particles ensuring soil fertility, structural and water strength factors for this case are also given in Table 1.

Example 4

Carried out, as in Example 2, but with the introduction of the suspension of nanobentonite indicated in Example 1 at the rate of 25.0 kg of nanobentonite (i.e. 125 l of this suspension) per 1 ha of sown area. Information on the proportion of particles ensuring soil fertility, structural and water strength factors for the case under consideration are shown in Table 1.

Example 5 (comparative)

Perform, as Example 2, but with the introduction specified in Example 1 suspension of nanobentonite at the rate of 10.0 kg of nanobentonite (i.e. 50 l of this suspension) per 1 ha of sown area. Indicators of the proportion of particles ensuring soil fertility, structural and water strength factors for this case, see Table 1.

Example 6 (comparative)

Perform, as in Example 2, but with the introduction of the suspension of nanobentonite indicated in Example 1 at the rate of 30.0 kg of nanobentonite (i.e. 150 l of this suspension) per 1 ha of sown area. The results of determining the proportion of particles ensuring soil fertility, the structural coefficient and water resistance for such a case are also shown in Table 1.

Example 7 (prototype [2])

They are carried out according to the general technology of Example 2, but with the introduction of bentonite at the rate of 9 tons per 1 ha of sown area (in the form of an aqueous suspension). Information on the proportion of particles ensuring soil fertility, structural and water strength factors for such a case are presented in Table 1.

Example 8 (prototype [2])

They are carried out according to the general technology of Example 2, but with the introduction of bentonite at the rate of 12 tons per 1 ha of sown area (in the form of an aqueous suspension). Data on determining the proportion of particles ensuring soil fertility, structural and water strength factors for such a case are presented in Table 1.

Example 9 (comparative, prototype [2])

They are carried out according to the general technology of Example 2, but with the introduction of bentonite at the rate of 25 kg per 1 ha of sown area (in the form of an aqueous suspension). The results of determining the proportion of particles ensuring soil fertility, the structural coefficient and water resistance for such a case are also presented in Table 1.

Example 10 (similar to [1])

Carried out according to the general technology of Example 2, but with the introduction of ethoxylated polyoxyethylene glycol into the soil at the rate of 12 kg per 1 ha of sown area (in the form of an aqueous suspension). The values of the fraction of particles ensuring soil fertility, structural and water strength coefficients for such a case are also presented in Table 1.

Example 11 (comparative, similar to [1])

Carried out according to the general technology of Example 2, but with the introduction of ethoxylated polyoxyethylene glycol into the soil at the rate of 20 kg per 1 ha of sown area (in the form of an aqueous suspension). The results of determining the proportion of particles ensuring soil fertility, structural and water strength factors for such a case are also presented in Table 1.

Example 12 (control)

They are carried out according to the general technology of Example 2, but no additives are introduced into the soil. Data on determining the fraction of particles ensuring soil fertility, structural and water strength factors for such a case are also presented in Table 1.

As can be seen from the data shown in Table 1, when using the method proposed by the authors, there is a significant improvement in indicators that determine the degree of structure of the soil, namely, a significant increase in the proportion of particles with sizes in the range (0.25-10.0) mm, as well as the coefficient of structure and water resistance in comparison with those for the prototype method [2]. This despite the fact that the amount of nanobentonite required to achieve the goal is almost three orders of magnitude less than the amount of bentonite used in the prototype method [2]. In this regard, we note that the range of amounts of nanobentonite claimed by the authors per 1 ha of cultivated area, namely (15.0-25.0) kg, is claimed to be significant, and when it goes beyond its lower boundary, there is a decrease in the above technical effect when leaving the upper - essentially an excessive consumption of nano-bentonite, because a further increase in the above indicators is stopped (see the data of Examples 2-4 and 5-6).

LITERATURE

1. RF patent No. 2430951 (analogue).

2. T.H. Ishkaev, Sh.A. Aliev, I.A. Yapparov. Agroecological aspects of the integrated use of local raw materials and non-traditional agro-ore in agriculture. Kazan, Center for Innovative Technologies, 2007. S. 99-101 (prototype).

3. V.V. Medvedev. Soil structure (methods, genesis, classification). Kharkov, Publ. "13 typography", 2008. S. 402-405.

Claims (1)

A method of improving the soil structure by preliminarily applying a structure-forming additive, plowing, harrowing and cultivation onto its surface, characterized in that nanobentonite is used as the specified additive, which is applied to the soil surface in the amount of 15.0-25.0 kg per 1 ha of sown area.