JP2008035860A - Mulch film substitute for agriculture, method for producing the same and production kit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mulch film substitute for agriculture decomposable by microorganisms in soil at extremely high speed compared with mulch film for agriculture made of a biodegradable resin and effective for suppressing the increase of ground temperature and the germination of weed seeds comparable to the suppressing effect attained by mulch films for agriculture made of a synthetic resin, a method for producing the mulch film substitute and a production kit for the method. <P>SOLUTION: The production kit for the mulch film substitute for agriculture is provided with an aqueous solution of sodium alginate and an aqueous solution of a calcium salt containing a pigment component. When these two aqueous solutions are applied or sprayed on the ground surface, both solutions are reacted with each other on the ground surface to form a film of calcium alginate containing the pigment component, i.e. a substitute for mulch film for agriculture on the ground surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an agricultural multi-film substitute that can be used in place of a conventional agricultural multi-film made of synthetic resin, a manufacturing method thereof, and a manufacturing kit thereof.

  Agricultural multi-films are used for the purpose of suppressing the rise in soil temperature, delaying weed growth, preventing soil erosion due to wind and rain, etc. It is widely used to cover the roots of fruit trees before harvesting.

  Agricultural multi-films are usually made of synthetic resin, and generally vinyl chloride films and polyethylene films are used. However, it cannot be decomposed naturally and must be removed from the farmland after use, incinerated, or disposed of. Therefore, work labor and cost required for removal, incineration, etc. are a problem. Therefore, in order to eliminate the need for removal, incineration, etc., agricultural multi-films composed of biodegradable and photo-disintegratable resins that are decomposed when the crop growing season is over have been developed.

  These agricultural multi-films made of biodegradable resins and photo-disintegrating resins are decomposed by microorganisms in the soil or disintegrated by sunlight, so that the removal work in farmland is saved, and incineration and disposal It is attracting attention as a labor-saving and environmentally friendly material for human work. However, there is a problem that it takes a long time until complete biodegradation or photodegradation, and it may be disadvantageous in terms of cost because it is expensive.

On the other hand, by applying calcium carbonate on the agricultural multi-film made of synthetic resin, it is possible to further suppress the rise in the ground temperature than simply covering with multi-film. It has been reported that there was an effect such as increasing the weight (Non-patent Document 1).
Osamu Ide, “Stable production technology for summer spinach using a full-open house”, Agriculture and Horticulture, Seibundo Shinkosha, 2005, September, p. 40-44

  Therefore, in view of the above problems, the present invention is decomposed by microorganisms in the soil much more quickly than agricultural multifilm made of biodegradable resin, and is equivalent to agricultural multifilm made of synthetic resin. An object of the present invention is to provide an agricultural multi-film substitute, a method for producing the same, and a kit for producing the same, which have the effect of suppressing the rise in soil temperature and the suppression of germination of weed seeds.

  In order to achieve the above object, the present invention, as one aspect thereof, is a method for producing an agricultural multi-film substitute, which comprises applying a sodium alginate aqueous solution and a calcium salt aqueous solution containing a pigment component to the ground surface. Alternatively, by spraying, the two aqueous solutions react to form a calcium alginate film containing the pigment component on the ground surface.

  The pigment component is preferably at least one selected from the group consisting of calcium carbonate, barium carbonate, gypsum, clay, silica powder, finely divided silicic acid, diatomaceous earth, kaolin, talc, and basic magnesium carbonate. Moreover, it is also preferable to use the coloring material recognized as a natural pigment or a food additive as the pigment component. As the calcium salt, calcium lactate is preferably used. The aqueous sodium alginate solution or the aqueous calcium salt solution preferably contains a dry curing agent. Moreover, when it contains a dry hardening | curing agent, it is preferable that the said sodium alginate aqueous solution or the said calcium salt aqueous solution contains an adhesive agent further.

  Another aspect of the present invention is a kit for producing an agricultural multi-film substitute comprising an aqueous sodium alginate solution and an aqueous calcium salt solution containing a pigment component, wherein the two aqueous solutions are ground. When coated or dispersed on the surface, it reacts to form a calcium alginate film containing the pigment component on the ground surface.

  As yet another aspect, the present invention is an agricultural multi-film substitute, characterized in that it is made of a calcium alginate coating containing a pigment component and formed directly on the ground surface.

  As described above, the aqueous sodium alginate aqueous solution and the calcium salt aqueous solution react to form a water-insoluble gel-like calcium alginate film uniformly on the ground surface. Will be dispersed throughout the film. And since sunlight reflects with the pigment | dye component disperse | distributed to this membrane | film | coat, the raise of the ground temperature of the part covered with the membrane | film | coat can be suppressed. Moreover, since the ground surface is covered with a gel-like film without any gaps, germination of weed seeds can be suppressed. Further, the gel-like film is easily broken and the main component calcium alginate is also rapidly decomposed by microorganisms in the soil, so that it can be removed very easily.

  Therefore, according to the present invention, it is decomposed by microorganisms in the soil much more quickly than the agricultural multifilm made of biodegradable resin, and the temperature of the ground surface is the same as the agricultural multifilm made of synthetic resin. An agricultural multi-film substitute having an effect of regulating and inhibiting germination of weed seeds, a production method thereof, and a production kit thereof can be provided.

  Hereinafter, an embodiment of the present invention will be described. The agricultural multi-film substitute manufacturing kit according to the present invention comprises a sodium alginate aqueous solution and a calcium salt aqueous solution containing a pigment component.

  The sodium alginate aqueous solution preferably has a sodium alginate concentration of 0.5 to 10.0% by weight, more preferably 1.0 to 4.0% by weight. In addition, since the seaweed extract contains a large amount of sodium alginate, the seaweed extract can also be used.

  As the calcium salt of the calcium salt aqueous solution, it is preferable to use a water-soluble calcium salt such as calcium lactate, calcium chloride, calcium sulfate, calcium formate, etc. Among them, calcium lactate is particularly preferable from the viewpoint of moderate solubility. In the case of a calcium lactate aqueous solution, the concentration of calcium lactate is preferably 0.5 to 4.0% by weight, and more preferably 2.0 to 4.0% by weight. Moreover, when it is set as calcium chloride aqueous solution, the density | concentration of calcium chloride has preferable 0.5-20.0 weight%, and 1.0-4.0 weight% is more preferable.

  The ratio of the amount of the sodium alginate aqueous solution to the calcium salt aqueous solution is such that the calcium ions in the calcium salt aqueous solution are in the range of 0.5 to 4.0 mol with respect to 1 mol of sodium ions in the sodium alginate aqueous solution. Preferably, the range is 1.0 to 2.0 mol.

  As the pigment component, at least one selected from the group consisting of calcium carbonate, barium carbonate, gypsum, clay, silica powder, finely divided silicic acid, diatomaceous earth, kaolin, talc, and basic magnesium carbonate is used as a water-insoluble one. It is preferable. These are white and can reflect sunlight efficiently and can suppress the rise in ground temperature remarkably. These pigment components are preferably contained in an amount of 100 g per 200 to 2000 mL of the calcium salt aqueous solution, and more preferably 100 g per 100 to 1000 mL of the calcium salt aqueous solution.

  Moreover, as a pigment | dye component, it is also preferable to use the coloring material recognized as natural pigment | dyes or food additives, such as a caramel, a turmeric pigment | dye, and a safflower pigment | dye, for example. By using these natural pigments or coloring materials, colors other than white can be expressed. These pigment components are preferably contained in an amount of 100 g per 200 to 2000 mL of the calcium salt aqueous solution, and more preferably 100 g per 100 to 1000 mL of the calcium salt aqueous solution.

  Then, by applying or spraying a sodium alginate aqueous solution and a calcium salt aqueous solution containing a pigment component to the ground surface, the two aqueous solutions react to form a calcium alginate coating containing the pigment component on the ground surface. The

  As a method of applying these aqueous solutions, for example, there is a method of applying with a roller, a brush or the like. Moreover, as a method of spraying these aqueous solutions, for example, there is a method of spraying with a spray for spraying a chemical solution or a power sprayer.

The amount to be applied or dispersed is preferably in the range of 250 to 3000 mL of sodium alginate aqueous solution and 1.0 to 250 mL of calcium salt aqueous solution containing a pigment component per 1.0 m ^{2 of} the ground surface to be applied or dispersed. After applying or spraying one aqueous solution, the other aqueous solution can be applied or sprayed, or two aqueous solutions can be mixed and this mixed solution can be applied or sprayed, but a sodium alginate aqueous solution can be sprayed. Or after application | coating, it is preferable to spray or apply | coat the calcium salt aqueous solution containing a pigment | dye component. Moreover, the ground surface before apply | coating or spreading aqueous solution has a preferable dry state.

  By reacting the above two aqueous solutions, a water-insoluble gel-like calcium alginate film is uniformly formed on the ground surface. Since the above pigment component is dispersed in this film, it is possible to suppress the reflection of sunlight on the surface of the film and increase in the ground temperature of the portion covered with the film. Moreover, since this gel-like film | membrane adheres to the ground surface and covers the ground surface without gap, it can suppress that weed seeds germinate from the ground surface. Therefore, it can be used as an alternative to agricultural multi-sheets.

  Further, the gel-like film is easily broken and the main component calcium alginate is rapidly decomposed by microorganisms in the soil, so that removal and disposal can be performed very easily. At this time, calcium and other salts are mixed in the soil and permeate into the ground, thereby providing a fertilizer effect peculiar to these salts. Therefore, it is possible to save work labor and reduce the environmental load.

  In order to improve the adhesion, strength, and sprayability of the gel-like film, it is preferable to add a poorly water-soluble drying curing agent such as magnesium hydroxide, magnesium oxide, and magnesium carbonate. This dry curing agent is preferably added to the aqueous calcium salt solution. Moreover, it is preferable to contain 100g with respect to 200-2000 mL of calcium salt aqueous solution, and, as for this dry hardening | curing agent, it is more preferable to contain 100g with respect to 400-1000 mL of calcium salt aqueous solution.

  In order to improve the adhesion, strength and sprayability of the gel-like film, in addition to the above-mentioned drying curing agent, vinyl acetate resin, methylcellulose, calcium salt of carboxymethylcellulose, sodium starch glycolate, sodium starch phosphate, It is preferable to further add an adhesive such as sodium polyacrylate. This adhesive is preferably added to an aqueous sodium alginate solution. Moreover, it is preferable to contain 100g with respect to 1000-10000mL sodium alginate aqueous solution, and it is more preferable to contain 100g with respect to 1000-3000mL sodium alginate aqueous solution.

  In order to improve the strength and sprayability of the gel-like film, it is preferable to add a spray improver such as dicalcium phosphate or primary calcium phosphate. The spray improver is excellent in sprayability by a sprayer because the particles are very fine and hardly soluble in 0.2 to 2.0%. The spray improver is preferably added to the aqueous calcium salt solution. Moreover, it is preferable to contain 100g with respect to 500-2000 mL of calcium salt aqueous solution, and, as for this spray improvement agent, it is more preferable to contain 100g with respect to 1000-1500 mL of calcium salt aqueous solution.

  Summarizing the component ratio of the suspension aqueous solution in which the sodium alginate aqueous solution and the calcium salt aqueous solution containing the pigment component are combined, sodium alginate 0.5 to 5% by dry weight, water-soluble calcium salt (calcium lactate equivalent) 1 ˜6%, pigment component (calcium carbonate equivalent) remainder or 40 to 98% is preferable. Moreover, when adding said arbitrary component, it is preferable to substitute a part of pigment | dye component with the said arbitrary component. Specifically, sodium alginate 0.5-4%, water-soluble calcium salt (calcium lactate equivalent) 1-5%, pigment component (calcium carbonate equivalent) 40-80%, dry curing agent 15- 40%, preferably 30-40%, 1-15% adhesive such as vinyl acetate resin, preferably 3-15%, 5-15% spray improver such as dicalcium phosphate, preferably 5-10% It is preferable.

(Examples 1 and 2)
A sodium alginate aqueous solution having a concentration of 1 wt% and a calcium lactate aqueous solution having a concentration of 2 wt% were prepared. Then, 100 g of light calcium carbonate (trade name Silver W manufactured by Shiroishi Kogyo Co., Ltd.) per 400 mL was suspended in the calcium lactate aqueous solution. In the planter, the dry soil is raised to create a simulated cocoon of about 0.3 m × about 0.1 m. First, about 50 mL of a sodium alginate aqueous solution is uniformly sprayed thereon, and then lactic acid in which calcium carbonate is suspended. Similarly, about 50 mL of the aqueous calcium solution was sprayed uniformly. Sodium alginate and calcium lactate reacted immediately, and a white gel-like film was formed on the sprayed part with a uniform thickness (on the right side of the partition shown in FIG. 1 and the partition shown in FIG. 5). On the left).

(Comparative Example 1)
On the other hand, for comparison, a calcium carbonate slurry in which 200 g of calcium carbonate wettable powder (trade name Clefnon manufactured by Shiraishi Calcium Co., Ltd., 95% calcium carbonate, spreading agent) is prepared per 1000 mL of water is prepared as described above. About 50 mL was uniformly sprayed into the planter. A white layer of calcium carbonate was formed, but when the water dried, the surface of the layer had countless holes, and the ground surface could not be completely covered (left side of the photograph in FIG. 1). ). Moreover, when it sprayed in large quantities, the slurry flowed down from the soot.

(Comparative Example 2)
Further, a calcium carbonate slurry was prepared by suspending 95 g of light calcium carbonate (trade name: Silver W) and 5 g of bentonite per 500 mL of water, and about 50 mL was uniformly sprayed into the planter as described above. A white layer of calcium carbonate and bentonite was formed, but when the water dried, the surface of the layer was cracked and could not completely cover the ground surface (right side of the photograph in FIG. 5) ).

(Comparative Example 3)
Furthermore, a calcium carbonate slurry was prepared by suspending 200 g of heavy calcium carbonate (trade name Softon 3200, manufactured by Bihoku Flour Chemical Co., Ltd.) per 1000 mL of water, and about 50 mL was uniformly sprayed into the planter in the same manner as described above. A white layer of calcium carbonate was formed, but when the water dried, the surface of the layer cracked, and the ground surface could not be completely covered (right side of the photograph in FIG. 9). The left side of the photograph in FIG. 9 is a case where nothing is sprayed.

  Subsequent progress was observed for the films of Examples 1 and 2 and the layers of Comparative Examples 1 to 3. The gel-like films of Examples 1 and 2 were not particularly changed even on the next day after the formation, and maintained the white gel-like properties (the right side of the photograph in FIG. 2 and the left side of the photograph in FIG. 6). . On the other hand, the calcium carbonate layer of Comparative Example 1 was cracked on the surface of the layer (left side of the photograph in FIG. 2). In addition, the calcium carbonate layers of Comparative Examples 2 and 3 were greatly cracked (the right side of the photograph in FIG. 6 and the right side of the photograph in FIG. 10).

  Furthermore, there was rainfall 5 days after the film was formed, and the films of Examples 1 and 2 and the layers of Comparative Examples 1 to 3 were all exposed to rain (photos of FIGS. 3, 7, and 11). On the day after rain, the film of Example 1 partially flowed with rain, but the gel-like film still covered the ground surface (right side of the photograph in FIG. 4). The film of Example 2 had more parts washed away by rain than the film of Example 1, and the ground surface was partially exposed, but the gel-like property was maintained (the left side of the photograph in FIG. 8). ). On the other hand, the layers of Comparative Examples 1 and 2 were partially washed away by rain, so that the ground surface was exposed everywhere (the left side of the photograph in FIG. 4 and the right side of the photograph in FIG. 8). The layer of Comparative Example 3 was almost washed away by rain and could no longer be called a layer (right side of the photograph in FIG. 12).

(Example 3)
In addition to sodium alginate, calcium lactate, and calcium carbonate, dibasic calcium phosphate, magnesium hydroxide, magnesium oxide, and vinyl acetate resin were added at a weight ratio shown in Table 1 to prepare a suspension aqueous solution. And using this suspension aqueous solution, it tested about the adhesiveness and intensity | strength of sample AG. In addition, any suspension aqueous solution diluted 10 times with water was used for the test. The 10-fold dilution means that 20 g of the above sample is dissolved or suspended in 200 g of the aqueous suspension.

As an adhesion test, 200 g of an aqueous suspension was sprayed onto a 100 mm square leather flat plate with a sprayer and dried, and then the weight of the gel-like film remaining on the flat plate was measured. The results are shown in Table 1. In addition, in order to compare between samples, it converted into the weight per 1 m < ² > which the membrane | film | coat produced | generated. As shown in Table 1, the coating weights of samples A to E to which magnesium hydroxide or magnesium oxide was added were significantly increased compared to samples F and G to which neither magnesium hydroxide nor magnesium oxide was added. It was excellent in nature. Among them, the coating weights of samples A to D to which vinyl acetate resin was further added increased dramatically.

  As a strength test, 200 g of an aqueous suspension was sprayed on a commercially available wrap film with a sprayer and dried, and then the compressive strength of the gel-like film produced was measured with a physical property measuring apparatus (Rheometer CR200DX manufactured by Sun Scientific Co., Ltd.). It was measured. The results are shown in Table 1. In addition, an adapter having a diameter of 20 mm was used as a pressure-sensitive axis that senses the compressive strength in contact with the film in the physical property measuring apparatus. As shown in Table 1, the compressive strength was significantly improved in Samples A to E to which magnesium hydroxide or magnesium oxide was added, compared to Samples F and G to which neither magnesium hydroxide nor magnesium oxide was added. Among them, the compressive strength of Samples A to D to which vinyl acetate resin was further added significantly improved.

Example 4
In order to test the sprayability of the aqueous suspension, in addition to sodium alginate, calcium lactate and calcium carbonate, dicalcium phosphate, magnesium hydroxide, magnesium oxide and vinyl acetate resin were added at the weight ratio shown in Table 2, and Table 2 A suspension aqueous solution was prepared at a dilution ratio shown in FIG. Then, using a sprayer having a nozzle diameter of 1 mm, 200 g of this suspension aqueous solution was sprayed on a 100 mm square plate, and clogging of the nozzles of the sprayer was confirmed. The results are shown in Table 2. In Table 2, “△” indicates that clogging occurred during spraying and normal spraying cannot be performed, “◯” indicates that the load during spraying has increased, and “◎” indicates no abnormality. Shown with a mark.

  As shown in Table 2, the samples A to D in which the total of dicalcium phosphate, magnesium hydroxide, and magnesium oxide was 30% or less of the entire sample were nebulized even at a thin concentration of 7.5 to 10 times. Clogged the nozzle. On the other hand, the samples E to H, in which the total of dicalcium phosphate, magnesium hydroxide, and magnesium oxide was 40% or more of the entire sample, were not clogged even at a concentration of 5 to 7.5 times as high as the dilution factor. Good spraying was achieved. Moreover, the further improvement of sprayability was seen by making vinyl acetate resin into 10% or more (samples G and H).

An example of an agricultural multi-film substitute according to the present invention is shown on the right side of the partition, and a comparative example is shown on the left side of the partition. It is the photograph showing the state of the next day of formation of an example of the agricultural multi-film alternative of FIG. 1, and a comparative example. It is the photograph showing the state on the rainy day of an example of the agricultural multi-film alternative of FIG. 1, and a comparative example. It is the photograph showing the state of the next day of rainfall of an example of the agricultural multi-film alternative of FIG. 1, and a comparative example. It is a photograph showing another example of the agricultural multi-film substitute according to the present invention on the left side of the partition and another comparative example on the right side of the partition. It is the photograph showing the state on the day after formation of an example of the agricultural multi-film alternative of FIG. 5, and a comparative example. It is the photograph showing the state on the rainy day of an example of the agricultural multi-film alternative of FIG. 5, and a comparative example. It is the photograph showing the state on the day after the rain of an example of the agricultural multi-film alternative of FIG. 5, and a comparative example. It is the photograph showing another comparative example on the right side of the partition. It is the photograph showing the state of the next day of formation of the comparative example of FIG. It is the photograph showing the state of the rainy day of the comparative example of FIG. It is the photograph showing the state of the day after the rain of the comparative example of FIG.

Claims (8)

  A sodium alginate aqueous solution and a calcium salt aqueous solution containing a pigment component are applied or dispersed on the ground surface, and the two aqueous solutions react to form a calcium alginate coating containing the pigment component on the ground surface. A method for producing agricultural multi-film substitutes.   2. The pigment component according to claim 1, wherein the pigment component is at least one selected from the group consisting of calcium carbonate, barium carbonate, gypsum, clay, silica powder, finely divided silicic acid, diatomaceous earth, kaolin, talc, and basic magnesium carbonate. A method for producing agricultural multi-film substitutes.   The method for producing an agricultural multi-film substitute according to claim 1, wherein the pigment component is a natural pigment or a colorant recognized as a food additive.   The method for producing an agricultural multi-film substitute according to claim 1, wherein the calcium salt is calcium lactate.   The method for producing an agricultural multi-film substitute according to claim 1, wherein the sodium alginate aqueous solution or the calcium salt aqueous solution contains a dry curing agent.   The method for producing an agricultural multi-film substitute according to claim 5, wherein the sodium alginate aqueous solution or the calcium salt aqueous solution contains an adhesive.   A kit for producing an agricultural multi-film substitute comprising a sodium alginate aqueous solution and a calcium salt aqueous solution containing a pigment component, wherein the two aqueous solutions react when applied or sprayed on the ground surface. And a production kit for forming a calcium alginate film containing the pigment component on the ground surface.   An agricultural multi-film substitute consisting of a calcium alginate film containing a pigment component and formed directly on the ground surface.