HU197168B - Process for preparing soil regenerating compositions with high capacity for adsorbing water - Google Patents

Abstract

Highly water retentive soil regenerating agent is prepd. when 50-60 wt.% acrylic monomer pref. acrylic and/or methacrylic acid, 0.05-5 wt.% crosslinking agent pref. alkylidene-bis-acrylamide e.g. N,N'-methylene-bis-acrylamide and/or ethylene-glycol -di:methacrylate and 0.005-3% initiator pref. ammonium or potassium persulphate is gelled in aq. soln. The crosslinked poly-acid is neutralised with equivalent quantities of ammonium hydroxide and/or potassium hydroxide or ammonia gas. Optionally the gel is dried and comminuted.

Description

FIELD OF THE INVENTION The present invention relates to a process for the preparation of soil-regenerating compositions having high water retention properties, which contain both the organic matter and ions required for the crop to be cultivated and provide the water needed for germination of plant seeds and seedling development and growth. These effects are provided by the combination of a high water absorbent crosslinked polymer used in the compositions of the present invention and organic nutrient components such as humic substances, preferably humic acids, digested humates or biologically digested organic materials.

The combined use of organic or inorganic nutrients (fertilizers, composts or fertilizers) and water preservatives (such as clay minerals, synthetic organic and inorganic polymers) has become increasingly widespread in recent years.

Solid fertilizers and fertilizer suspensions containing clay have both a certain degree of ion exchange capacity and a favorable influence on the water balance of the soil due to their ability to retain water. In some cases, a combination of clay minerals and polymer forms a complex clay polymer gel system in the soil, which is capable of actively promoting nutrient cycling in crop production. Hungarian Patent Publication No. 151300 discloses a process for preparing a soil improvement composition in which peat is combined with a solution of linear polyvinyl alcohol and an ammonium solution of polyacrylic acid. The mixture containing other additives (ammonium nitrate, farmyard manure and limestone powder) is applied to the soil by deep plowing. Initially, the mixture has a significant water-binding capacity, but this property disappears in a short time due to the decomposition (mineralization) of the peat and the diffusion of the water-soluble plastic components. US Patent No. 2800068 mentions a process for soil improvement which involves injecting a dispersion of vinyl polymer, preferably vinyl propionate, into the soil.

Compositions in which the plastic is used in foamed form are known for improving the soil and increasing its air purity. In the process described in US Patent No. 3032271, phenol-formaldehyde or urea-formaldehyde resin foam is used to increase the aeration of the culture media and to improve the water balance. US Patent No. 3305997 mentions open-celled polyurethane foam, which is blended into the soil, thereby increasing the aeration of the soil, improving nutrient and water balance, and, when applied to the surface, also insulates the heat-insulating effect of the foam. Because of the relatively low viscosity of the plastic component (for example, in the case of polyurethane foam, water may only bind in the open pores of the pore system), the said compositions exert their ability to regulate nutrient flow primarily by increasing aeration of the soil.

Significantly greater water-binding capacity can be achieved using cross-linked polymers. In crosslinked polymers, macromolecules are bound to a coherent backbone, inhibit free diffusion, and, unlike linear polymers, do not dissolve in excess fluid but merely swell. The use of acrylamide-based copolymer networks is disclosed in British Patent 8124256 and German Patent Publication 3344638. In the composition of the English patent, the crosslinked copolymer is incorporated into the soil by admixture with additives (e.g. kaolin), thereby improving the water balance and aeration of the soil. In the cited US Patent, a high water crosslinking acrylamide sodium acrylate copolymer is prepared by copolymerization of 60-80% by weight of acrylamide and 40-20% by weight of sodium acrylate monomer. Other additives used in soil improvement include acid gels, stone dusts, perlite and clay minerals, preferably bentonite, montmorillonite or kaolinite. A common feature in the preparation of said acrylamide-based formulations is that the acrylamide monomer is copolymerized with an alkali salt of acrylate monomer. The polymerization of the salt-form monomers, by virtue of electrostatic repulsion between the charged groups, favors the formation of extended chain consolidations, which reduces swelling capacity. In addition, the fact that cations are incorporated into the network during cross-linking limits the possibility of developing their qualitative composition and quantitative ratios taking into account the physiological characteristics of the crops to be cultivated. However, the electrolyte sensitivity of swollen cross-linked networks, which are predominantly nonionic acrylamide units, is extremely high. The composition of the German Patent No. 33446318 is able to absorb only 20% of a 0.5% by weight aqueous calcium chloride solution as from distilled water. This high electrolyte sensitivity is due to the low charge density along the copolymer chains since only the acrylate salt is ionic in nature. Electrostatic repulsion between low ionic groups is also shielded by low concentrations of electrolytes dissolved in the medium.

In the course of our work, we have aimed to develop a process for the preparation of soil regeneration compositions having a high water retention capacity, which eliminates the shortcomings and disadvantages of the known processes, but has the following additional effects:

- the amount and composition of the organic and inorganic active substances may be adjusted within wide limits, according to the needs of the crops to be cultivated,

- the polymer skeleton can be fitted with both the main nutrients necessary for the plants (eg nitrogen, potassium) and the micronutrients (eg manganese, copper, titanium, zinc) required for the crops to be grown,

- the cross-linked polymer is capable of rapidly absorbing and gradually discharging large quantities of water and retains this property in the soil over long periods,

- the polymer component is more resistant to the swelling-reducing effect of the substances present in the soil,

- enables more economical use of irrigation technologies and reduces the number of irrigation, thus significantly reducing production costs.

The process of the present invention comprises 5 to 60% by weight of methacrylic acid monomer, or a mixture of methacrylic acid monomer and a water-soluble alkali and / or ammonium salt thereof, containing from 1 to 70 monomer units of salt per 100 monomer units, 0.02 to 5% by weight of alkylidene. bisacrylamide and / or ethylene glycol dimethacrylate, 0.005 to 3% by weight of the initiator, namely ammonium persulphate and / or potassium persulphate and optionally 5 to 30% by weight of an acrylic acid comonomer or an alkaline or ammonium salt thereof, are gelled, neutralized with alkali and a solution of ammonium hydroxide and / or potassium hydroxide or ammonia gas; or zeolite or a mixture thereof.

The present invention is based on the discovery that the cross-linked polymer composition prepared as described above is capable of rapidly absorbing and gradually discharging large amounts of water, which retains its property for a long time in the soil and provides the plants with water and nutrients. Our recognition is surprising in many ways. It is surprising that the polymer has an extremely high swelling capacity, since it has a water absorption capacity of 600-700 times per unit mass of dry web. This is particularly surprising because polymerization in a solution without a crosslinking agent results in a phase separation in the system, i.e., polymer-rich and polymer-poor compartments. It would be expected that the crosslinking would result in an inhomogeneous crosslinking network in which the highly entangled state of the chains is captured by chemical crosslinking, and as a result, the crosslinking is only slightly swellable. Surprisingly, however, in the case of polymerization in the presence of a crosslinker, the macroscopic spatial separation of the phases is not maintained, preserving the homogeneous nature of the system. A further surprising finding is that the high water absorption capacity of the crosslinked polymer remains in the soil. It would be expected that macromolecular components released from humic substances would significantly reduce the swelling capacity of the system for thermodynamic reasons.

The effect of the compositions of the present invention over the known compositions is in part due to the fact that all monomer units along the chain are ionic. As a result, on the one hand, the total amount of cations that can be linked to the network is significantly higher than that of any preparation made by known methods and, on the other hand, the composition and quantity ratios of ions can be adjusted to the needs of the crop. At the same time, due to the higher charge density, the electrolyte sensitivity of the crosslink is diminished.

Another important additional effect is related to the high water uptake and / or drainage capacity of the polymer component. In addition to being able to store and gradually release a significant amount of water, the crosslinked polymer also has a positive effect on the structure of the soil due to the volumetric changes associated with swelling and drying cycles.

1-5 illustrate the efficacy of the compositions of the present invention. Table 4 shows the results of comparative trials in a breeding pot. The experiments were carried out on dry, loamy, calcareous sandy soil with tomato, paprika and English meadow plants, with three replicate experiments. The treatment was carried out using a biologically produced organic compost containing 0.5% by weight of soil x crosslinked ammonium amide methacrylate polymer prepared in Example 1.

Table 1

Table 3

Details of tomato seedlings

Number of days height of seedlings / cm untreated soil handled soil 1 (planting) 18-20 18-20 6 22-25 24-28 10 25-28 28-30 15 28-30 35-38 20 28-30 43-45 25 30-32 55-60 30 30-32 65-70

Growth data for English lawn

Number of days Height / cm untreated soil handled soil 10 3 (germination) treatment X: 27 treatment X: 73 5 5-6 6-8 IC 5-6 10-12 14 6-8 12-14 20 6-8 15-17 15 25 6-8 17-20 1-3. from the data in tables, hstó, that a invention according to the procedure

Table 2 Details of paprika seedlings Number of days height of seedlings / cm untreated soil handled soil l (planting) 10-12 10-12 6 10-14 15 lpha 10 14-15 17-18 20 16-18 22-24 25 17-18 23-24

4th

the use of preparations obtained has a favorable effect on the development of plants; on the 25th day after planting and sowing, tomato seedlings had an average height of 100 X, pepper seedlings 40 X, and English frond height 150 X above control plants.

The progress of our procedure is illustrated by the test results summarized in Tables 4 and 5.

spreadsheet

Comparative test results for tomato seedlings

Number of days untreated sandy soil height of seedlings / cm Soil treated with Solacrol * soil improvers soil treated with the composition of the invention l (planting) 18-20 18-20 18-20 6 22-25 19-21 24-28 10 25-28 26-28 28-30 15 28-30 32-34 35-38 20 28-30 34-37 43-45 25 30-32 38-40 55-60 -, 30 30-32 38-42 65-70

* Solacrol, United Chemicals (Budapest): aqueous solution of polyacrylic acid

Table 5

Results of comparative trials with English litigation

Number of days Height / cm untreated sandy soil Solacrol * treated with soil improvers  soil soil treated with the composition of the invention 3 (germination) germination%: 27 germination%: 48 germination%: 73 5 5-6 6-7 6-8 10 5-6 7-8 10-12 14 6-8 8-10 12-14 20 6-8 8-11 15-17 25 6-8 10-12 17-20

* Solacrol, a manufacturer of United Chemicals (Budapest)

From the data in Tables 4 and 5 it can be seen that the development of both indicator plants on the soil treated with the composition of the invention is significantly faster than on untreated soil and after the known and applied Solacrolos treatment. In the English case, not only is growth faster, but also the growth rate is significantly higher (73% versus 27% and 48%, respectively).

The main advantages of the compositions of the present invention are as follows:

provide the macro - and micronutrients and trace elements necessary for the plants,

- the quantity and quality of the active substances may be adjusted to take account of the needs of the crops to be grown,

increasing the fertility of the soil,

- the rapid absorption and slow gradual water retention of the crosslinked polymer component allows significant amounts of irrigation water to be saved,

- favorably influence soil structure by increasing the aeration of the soil through periodic rotation of drying cycles,

- they are simple to produce and economical to use. 50

Hereinafter, some embodiments of the present invention will be provided. The examples illustrate the invention. They are not intended to be a restriction, they merely serve to illustrate implementation.

Example 1

Increasing the water retention capacity of flower buds kg of methacrylic acid monomer, 0.5 kg of ammonium methacrylate monomer, 0.15 kg of N, N '-65 methylene bisacrylamide, 0.05 kg of ammonium persulfate are dissolved in 80 kg of distilled water. The mixture was deoxygenated with argon and polymerized at 90 ° C. After completion of the reaction, the system is neutralized with a 25% (w / v) stoichiometric solution of the ammonium hydroxide solution. The gel is dried at 110-120 ° C and the dry polymer is ground to a particle size of 0.2-1.2 mm. The 1: 1 weight ratio of lignite powder is mixed with 0.3% by weight of nutrient-rich flower heads and utilized as potted ornamental plants, balcony flower boxes or roof gardens. In the case of plants grown in this way, due to the increased water capacity of the soil, the number of irrigations required is significantly reduced and about 50-60% of the irrigation water can be saved.

Example 2

Roof gardens, balcony flower boxes and potted ornamental soil design

2% by weight of the cross-linked ammonium methacrylate polymer prepared in Example 1 was blended with an air-dry biocomposite enriched with natural minerals. The mixture was diluted 1: 10 with flower soil. The composition is advantageously used as a soil for roof gardens, balcony flower boxes and ornamental plants. The masterbatch can also be used to refresh the soil (nutrient supply) by replacing the top 1-2 cm of soil with irrigation from above. When the composition is applied, watering is much less frequent, and the foliage, flower formation and fiber strength of the plants increases.

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Example 3

Improvement of loose sandy soils from a mixture of kg of methacrylic acid, 6 kg of 25% w / w ammonium hydroxide solution, 0.2 kg of N, N'-methylenebisacrylamide, 0.07 kg of potassium persulphate and 67.3 kg of distilled water prepared. The system is degassed by bubbling nitrogen and polymerized at 95 ° C. The crosslinked material is neutralized with a stoichiometric amount of ammonium hydroxide solution. The gel is dried at 105 ° C in a tray drier in a stream of air to constant weight. The dry polymer is ground in Koller Malora to a particle size of 0.3-2.5 mm and then mixed in a 1: 5 weight ratio with 21-28% organic matter-rich natural minerals (clay, zeolite). The mixture is added depending on the organic matter content of the soil in an amount such that the treatment results in an organic matter content of at least 6% by weight in the top 10 cm of the soil. The treatment yields about 15-20% of the excess crop for shallow-rooted plants such as gramine and garden flowers.

Example 4

Improvement of sandy soils and low-humus loam soils from kg of methacrylic acid monomer, 0.1 kg of potassium methacrylate, 22 kg of acrylic acid monomer, 0.15 kg of N, N'-methylenebisacrylamide, 0.08 kg of ammonium persulfate and 78 kg of distilled water . The mixture was deoxygenated with carbon dioxide and heated to 90 ° C. After the polymerization is complete, the system is neutralized with an equivalent amount of saturated potassium hydroxide solution and dried at 120 ° C to constant weight. The dry material is crushed in a knife or hammer crusher to a particle size of 0.5-3 mm. The material thus obtained is mixed with the cross-linked ammonium methacrylate polymer powder prepared in Example 1 in a weight ratio of 1: 1. The mixture is diluted 1: 5 by weight with 21-28% by weight organic matter-rich compost enriched with natural minerals and trace elements (manganese, copper, titanium, zinc). The composition is applied to the soil at a depth of 30 cm, with a layer thickness of 8-10 cm, spread on a mat, preferably using a winged laminate. 1.2-1.6 t is used per hectare. The treatment results in a 25-30% yield increase for deep-rooted arable crops (such as alfalfa, sugar beet) and standing crops, as well as for the cultivation of garden plants such as vegetables, roots and tubers, especially in their irrigated crops.

Example 5

Improvement of arid (desert) soils

The crosslinked ammonium methacrylate polymer powder prepared in Example 1 is blended in a 1: 3 weight ratio with biologically digested compost enriched with natural minerals and trace elements. The mixture can be used for vertical soil improvement in the following ways:

- approx. At a depth of 30 cm, a carpet-like layer of 8-10 cm thickness is formed with a wing-laminator or slitting plow. At the same time, water is injected into the layer through a separate opening of the deep delivery device. The discharged mixture swells as a result of water uptake, forms a zero layer and retains precipitation and irrigation water. The amount of material to be used is 1.5-2 t per hectare. As a result of the treatment, 50-60% of the irrigation water can be saved.

- In the course of improving the surface layer of the soil, which occurs after the deeper layers have been repaired, 1.2-1.8 t of the mixture per hectare are added to the top 10 cm of soil.

In addition to the already mentioned irrigation water savings, the vertically repaired soil section results in an average yield increase and quality improvement of 22-25% for both horticultural and field crops.

Example 6

Lawn planting, lawn surface formation from kg ammonium methacrylate, 10 kg potassium methacrylate, 10 kg acrylic acid monomer, 10 kg methacrylic acid monomer 0.12 kg N, N-methylene bis-acrylamide, 0.02 kg ethylene dimethacrylate, 0.05 kg A solution of ammonium persulfate and 80 kg deionized water was prepared, deoxygenated by bubbling carbon dioxide and heated to 92 ° C. After polymerization, the gel is neutralized with a stoichiometric amount of saturated potassium hydroxide solution and then dried at 100 ° C to constant weight. The dry polymer is crushed with a hammer crush to an average particle size of 1 to 2 mm and then mixed in a 1: 8 weight ratio of compost enriched with natural minerals. The mixture is applied in a shallow depth of 0.6-0.8 kg / m ^{2 to} the upper 5 to 8 cm soil layer, preferably with a soil mill. THE

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Treatment I increases the germination rate and strength of the grass seed by at least 45-50% and also promotes shrubbery.

Example 7

Regeneration of garden soils

The crosslinked ammonium methacrylate polymer prepared in Example 1 is blended with biologically degraded organic minerals in a weight ratio of 1 to 6 for the regeneration of vegetable and fruit gardens, greenhouses, and foil tents. The mixture is applied to the surface layer 20 cm thick with a milling cutter. Consumption: 3-4 kg / ² . In regenerated soils, the growth power and productivity of the plants increases by about 20%. In case of irrigated farming the number of irrigations decreases, and in case of dry farming the prevalence of natural (atmospheric) precipitation increases.

Example 8

Establishment of medium for seedling cultivation

The composition of Example 3, a crosslinked ammonium methacrylate polymer and a biologically digested organic bonded mineral, is mixed with garden soil in a 1: 5 weight ratio, and the seed is sown or seeded. The medium provides the young plant units with so-called starter water and nutrient surplus for initial development. The germination rate reaches 75-85%.

Example 9

Masterbatch For commercial crop production, 10 kg of a 25% w / w solution of ammonium hydroxide are added to kg of methacrylic acid monomer with continuous stirring. 0.1 kg 0,1, Ν'-methylenebisacrylamide and 0.04 kg ammonium persulfate were dissolved in the mixture. The polymerization is initiated by heat transfer (at about 80 'C). After completion of the reaction, the free acid is neutralized with 20% w / w potassium hydroxide solution. The gel is dried in a βΟΧί-οη air stream and crushed in a hammer breaker to a particle size of 0.2-1.8 mm. The flour was homogenized in a 1: 5 weight ratio with a mixture of 4 parts biocompost and 1 part lignite powder. The composition is applied to the soil at a depth of 8 to 12 cm at the same time as plowing or sowing. Consumption per hectare is 1.2-1.5 t. Irrigation water savings of 25-30%, while at the same time about 10-15% yield increase.

Example 10

General purpose base mix for increasing the water retention capacity of soils with poor water retention capacity from kg of methacrylic acid, 1 kg of potassium methacrylate, 0.05 kg of Ν, metil'-methylene-blle-acrylarylide, 0.08 kg of potassium persulphate

A solution of 59 kg of distilled water is prepared. The mixture was degassed by bubbling nitrogen and gelled at 90 ° C. After polymerization, the system was quenched with 25% w / w ammonium hydroxide solution and then dried at 110 ° C to constant weight. The dry polymer is ground in a roller passage to a grain size of 0.5-3 mm. To 1 part by weight of flour is added 2 parts by weight of a 1: 1 weight mixture of lignite powder and peat. After homogenization, the composition is applied to the soil at a depth of the root zone, spread in a thin layer. The amount of material to be used is 1-1.5 t per hectare. The evenly distributed material swells in contact with water to form a coherent layer that prevents irrigation and rainwater from leaking into deeper soil layers. The water retention capacity of the soil is greatly improved and at least 50% of your 30 water can be saved.

Claims (1)

PATENT CLAIMS 1. The method is highly viscous 35 for the preparation of soil regeneration compositions, characterized in that a mixture of 5 to 60% by weight of methacrylic acid monomer and a water-soluble alkali and / or ammonium salt of 0.1 to 70 per 100 monomer units It contains 40 monomer units of salt and 0.02-5% by weight of a crosslinking agent, and preferably alkylidene bisacrylamide, preferably N, N'-methylene bisacrylamide and / or ethylene glycol dimethacrylate, 0.005-3% by weight of an initiator such as ammonium per45. an aqueous solution containing sulfate and / or potassium persulfate and optionally 5-30% by weight of acrylic acid comonomer is polymerized at 50-140 ° C, with the free acid in an alkali, preferably aqueous solution of ammonium hydroxide and / or potassium hydroxide or ammonia neutralizing with gas, removing volatile components from the resulting gel by drying, crushing the polymer and 1 to 20 parts by weight, based on 1 part by weight of dry polymer, of biologically digested organic material, preferably compost or peat or lignite powder or clay or earth homogenize with a mixture thereof.