JP7803181B2 - Mulching material, formwork, and method for manufacturing mulching material - Google Patents

Description

The present invention relates to mulching materials, forms, and methods for manufacturing mulching materials.

Mulching materials used to cover the soil surface of fields have been known for some time. For example, Non-Patent Document 1 discloses a mulching material made from a plastic material. Patent Document 1 discloses a mulching material made by weaving straw. Patent Document 2 discloses a technique for producing a mulching material by fixing stacked straw to a substrate. Patent Document 3 discloses a technique for producing a mulching material by forming finely divided thinning materials or the like into sheets.

Japanese Patent Application Publication No. 11-61834 Japanese Patent Application Laid-Open No. 2001-45881 Japanese Patent Application Laid-Open No. 2006-271242

Mitsuhiro Inoue, "Soil evaporation control and temperature environment using various mulch materials," Agriculture and Horticulture, Vol. 82, No. 6 (2007), pp. 683-686

However, even with prior art such as Non-Patent Document 1 and Patent Documents 1, 2, and 3, there is still room for improvement in technology for further reducing environmental impact. For example, with the technology described in Non-Patent Document 1, the mulching material is made from a plastic material that does not naturally decompose in the natural environment, so mulching material that has deteriorated over time must be collected and disposed of. In this case, incineration generates harmful gases, which may increase the environmental impact. With the technologies described in Patent Documents 1 to 3, in order to form straw or thinned wood into sheets, it is necessary to use resin strings to bundle the straw and adhesives to adhere the thinned wood. For this reason, when using the mulching materials described in Patent Documents 1 to 3, the materials do not completely decompose in the natural environment, which may result in residues being left behind in fields.

The present invention was made to solve the above-mentioned problems, and aims to provide technology that can reduce the environmental impact of mulching materials.

The present invention has been made to solve at least some of the above-mentioned problems, and can be realized in the following forms.

(1) According to one aspect of the present invention, there is provided a mulching material used to cover the soil surface of a field. This mulching material has a plate-like shape in which plant roots are intertwined with each other.

With this configuration, the mulching material is made from plant roots. This means that even if the mulching material becomes unnecessary or is torn into small pieces, it will decompose in the natural environment, reducing the environmental impact on fields.

(2) The mulching material of the above embodiment may contain soil held by the intertwined plant roots. According to this configuration, the mulching material contains soil held by the intertwined plant roots. This allows the soil to fill in the gaps between the intertwined plant roots, making it easier to cover the soil surface of the field. Furthermore, the weight of the mulching material increases, preventing the mulching material from being blown away by wind and rain. Therefore, the state in which the mulching material covers the soil surface of the field can be maintained for a relatively long period of time.

(3) In the mulching material of the above embodiment, the soil may include soil from the field where the mulching material is used. According to this configuration, the soil contained in the mulching material includes soil from the field where the mulching material is used. As a result, nutrient-containing field soil is used as mulching material, and the nutrients contained in the soil can be supplied to crops. Furthermore, even if plant roots decompose after the mulching material is used and the soil held by the plant roots remains in the field, it is soil from the same field and does not affect the field environment. Therefore, the environmental impact of the field can be further reduced.

(4) In the mulching material of the above embodiment, the plants may have portions of their stems cut off. With this configuration, the mulching material is formed from the remaining root portions of plants after the stems have been cut off. Because the mulching material is formed into a plate-like shape by the intertwined roots of the plants, it is easier to cover the soil surface of the field without the stems.

(5) In the mulching material of the above embodiment, the plants may be annual plants. According to this configuration, the mulching material is formed by intertwining the roots of annual plants that grow, flower, and then die. This prevents the plants used in the mulching material from growing while the mulching material is being used. This prevents the plants used in the mulching material from damaging the field environment.

(6) In the mulching material of the above embodiment, the plant may be a green manure plant. According to this configuration, the mulching material uses a green manure plant that has the effect of repelling nematodes that cause damage to crops in the field. This can reduce damage to crops caused by nematodes.

(7) In the mulching material of the above form, the plants may include co-prosperous crops with the field crops to which the mulching material is applied. According to this configuration, the mulching material is formed from co-prosperous crops that promote the growth of the field crops. This makes it possible to prevent crop diseases and promote crop growth.

(8) According to another aspect of the present invention, there is provided a formwork used to produce mulching material. This formwork comprises a pair of opposing flat plate members, and at least a portion of the outer periphery of the pair of flat plate members is open so that the space between the pair of flat plate members is not sealed. According to this configuration, the formwork used to produce mulching material has at least a portion of the outer periphery of the pair of flat plate members open so that the space between the pair of flat plate members is not sealed. This allows sufficient air and water to be supplied to the roots of plants growing between the pair of flat plate members when the formwork is placed in the soil. This allows the roots of plants to grow between the pair of flat plate members.

(9) The formwork of the above embodiment may further include a connecting portion connecting the opposing ends of the pair of flat plate members, and each of the pair of flat plate members may be formed so that the width of the end opposite the end connected to the connecting portion is smaller than the width of the end connected to the connecting portion. According to this configuration, the pair of flat plate members are formed so that the width of the end opposite the end connected to the connecting portion is smaller than the width of the end connected to the connecting portion. This makes it easier to install the formwork in the soil when producing mulching material in the soil by driving the narrowed end into the soil. Therefore, mulching material can be easily produced.

(10) According to yet another aspect of the present invention, there is provided a method for manufacturing a mulching material. The method for manufacturing a mulching material comprises a first step of growing plant roots between a pair of flat plate members buried in soil, and a second step of removing the plant roots grown in the first step from between the pair of flat plate members. According to this configuration, the method for manufacturing a mulching material includes growing plant roots in the space between the pair of flat plate members placed in the soil, and then removing the plant roots from between the pair of flat plate members. This makes it possible to produce a mulching material having a plate-like shape in which the plant roots intertwine with each other, just like growing plants.

(11) The method for manufacturing mulching material of the above embodiment may include a third step, prior to the first step, of placing the pair of flat plate members in the soil of the field where the mulching material will be used. With this configuration, the formwork is placed in the soil of the field where the mulching material will be used, so the mulching material can be manufactured at the site where it will be used. This eliminates the need to transport the manufactured mulching material.

The present invention can be realized in various forms, such as a structure having a plate-like shape in which plant roots intertwine with each other, a method for manufacturing this structure, a member including this structure, and a method for using mulching material.

1 is a schematic diagram showing the general configuration of a mulching material according to a first embodiment. FIG. FIG. 2 is a schematic diagram showing the general configuration of a structure included in a mulching material. FIG. 1 is a cross-sectional view of a mulching material. FIG. 1 is a first schematic diagram showing a general configuration of a formwork. FIG. 2 is a second schematic diagram showing the general configuration of the formwork. FIG. 1 is a first diagram illustrating a method for manufacturing mulching material. FIG. 2 is a second diagram illustrating a method for manufacturing mulching material. FIG. 3 is a third diagram illustrating a method for manufacturing mulching material. FIG. 4 is a fourth diagram illustrating a method for manufacturing mulching material. FIG. 5 is a fifth diagram illustrating a method for manufacturing mulching material. FIG. 10 is a diagram illustrating an example of the use of mulching material. FIG. 10 is a diagram illustrating an example of use of the mulching material of the second embodiment.

First Embodiment
FIG. 1 is a schematic diagram showing the overall configuration of a mulching material according to a first embodiment. FIG. 2 is a schematic diagram showing the overall configuration of a structure included in the mulching material according to the first embodiment. FIG. 3 is a cross-sectional view of the mulching material, taken along line A-A in FIG. 1. The mulching material 1 according to this embodiment is used for mulching to cover the soil surface of a field. Mulching has the effects of preventing the soil surface of a field from drying out, preventing soil erosion by absorbing the impact of raindrops, mitigating soil temperature changes by blocking sunlight, and suppressing weed growth by blocking direct sunlight, and is therefore useful for field crops. In this embodiment, the mulching material 1 is used in the cultivation of tomatoes, sweet potatoes, and the like. The mulching material 1 includes plant roots 10a and soil 20.

The plant roots 10a intertwine to form a structure 5 having a generally plate-like shape S5 (see Figure 2). The structure 5 has a generally pentagonal shape, which is the shape of the formwork (described below) used to manufacture the mulching material 1. In this embodiment, the plant whose roots 10a form the structure 5 is a green manure plant of the Poaceae family, such as rye or oats, which are known to repel nematodes. Here, rye is used. Rye is an annual plant that flowers once and then dies, so it does not grow when used in a field as the mulching material 1. In the structure 5, the plant roots 10a are intertwined, resulting in many gaps, as shown in Figure 2. Portions of the rye stems 10b remain in the mulching material 1 shown in Figures 1 and 2.

The soil 20 is held in place by the plant roots 10a. Specifically, as shown in Figure 3, much of the soil 20 contained in the mulching material 1 is held in place by entering the gaps between the intertwined plant roots 10a. Furthermore, some of the soil 20 contained in the mulching material 1 is held in place by adhering to the plant roots 10a. The soil 20 accounts for a large portion of the weight of the mulching material 1.

Next, we will explain the manufacturing method of the mulching material 1. In this embodiment, the mulching material 1 is manufactured using a formwork in the field where the manufactured mulching material 1 will be used.

Figure 4 is a first schematic diagram showing the general configuration of the formwork, showing a front view and a plan view of the formwork. Figure 5 is a second schematic diagram showing the general configuration of the formwork, showing a side view of the formwork. Here, the configuration of the formwork 30 used to manufacture the mulching material 1 will be described. The formwork 30 comprises a pair of flat plate members 31, two connecting portions 32, and two handle portions 33. The formwork 30 is formed from natural materials such as wood. As a result, the formwork 30 will decompose in the natural environment even if left at the site (field) where the mulching material 1 is used after use, eliminating the need for disposal. The formwork 30 may also be formed from metal or plastic.

Each of the pair of flat plate members 31 is a substantially flat plate-like member with the same shape and is arranged facing each other. As shown in FIG. 4(a), the flat plate member 31 has a substantially pentagonal shape when viewed from the front. The flat plate member 31 has a base end 31a to which the connecting portion 32 (described below) is connected, and a tip end 31b on the opposite side that tapers toward the tip. Specifically, as shown in FIG. 4(a), the width Wb of the tip end 31b is smaller than the width Wa of the base end 31a, and as shown in FIG. 5, the thickness Db of the tip end 31b is smaller than the thickness Da of the base end 31a. This makes it easier to drive the tip end 31b of each of the pair of flat plate members 31 into the soil.

The two connecting portions 32 connect the base ends 31a of the pair of flat plate members 31. The connecting portions 32 connect the pair of flat plate members 31 so that the distance d between the pair of flat plate members 31 is the same as the thickness of the mulching material 1 (thickness d shown in FIG. 3) (see FIG. 4(b)). In this embodiment, when manufacturing the mulching material 1 using the formwork 30, the connecting portions 32 can be easily disconnected from the pair of flat plate members 31 to make it easier to remove the mulching material 1 from the formwork 30.

Two handles 33 are attached to each of the two connecting parts 32. When manufacturing mulching material 1 using formwork 30, the manufacturer of mulching material 1 can hold the handles 33 to drive formwork 30 into the soil or pull it out of the soil.

5, in the formwork 30 of this embodiment, the outer periphery of the pair of flat plate members 31 is open except for the portion where the connecting portion 32 is connected so that the space 30a between the pair of flat plate members 31 is not sealed. This allows sufficient air and water to be supplied to the roots 5a of plants growing in the space 30a when the formwork 30 is placed in the soil.

Next, we will explain the manufacturing method of mulching material 1. In this embodiment, mulching material 1 is manufactured in the field where the manufactured mulching material 1 will be used. This reduces the transportation costs of the manufactured mulching material 1.

Figure 6 is the first diagram illustrating a method for manufacturing a mulching material. In the method for manufacturing a mulching material 1 of this embodiment, first, a formwork 30 is embedded in the soil 91 of a field 90 (third step). Specifically, the tip 31b of the formwork 30 is brought into contact with the soil surface 92 of the field 90, and then a force F1 is applied to each of the two handles 33, driving each of the pair of flat plate members 31 into the soil 91. In this embodiment, for example, as shown in Figure 6, multiple formworks 30 are lined up horizontally to simultaneously manufacture multiple mulching materials 1.

Figure 7 is a second diagram illustrating a method for manufacturing mulching material. Figure 7 shows a view from above a field 90 of multiple formwork 30 embedded in soil 91. After the formwork 30 is driven into the soil 91, rye seeds S1 are sown in rows on the soil surface 92 between the pair of flat plate members 31 and covered with soil.

After sowing seeds S1 on the soil surface 92 between the pair of flat plate members 31, rye is grown while providing water and fertilizer, as with ordinary crops (Step 1). During this process, rye roots 10a grow in the spaces 30a within the soil 91. Their growth direction is restricted by the pair of flat plate members 31, forming a structure 5 with an intertwined, flat-plate-like shape. In this embodiment, as the rye roots 10a form the structure 5, the soil in the spaces 30a is absorbed into the structure 5. As a result, a mulching material 1 is formed in the spaces 30a, composed of the rye roots 10a and the soil in the spaces 30a.

Figure 8 is a third diagram illustrating a method for manufacturing a mulching material. Rye grown between a pair of flat plate members 31 has roots 10a as well as stems and leaves. In this embodiment, as shown in Figure 8, the stems 10b of the rye 10 are cut with a blade 11 while the mulching material 1 is in the soil 91 together with the formwork 30. Note that the stems 10b of the rye 10 may also be cut after the mulching material 1 is removed from the soil 91.

Figure 9 is the fourth diagram illustrating the method for manufacturing mulching material. After cutting the stems 11b of the rye 10, the mulching material 1 is removed from the soil 91. Specifically, a force F2 is applied to each of the two handles 33, and the roots 10a of the rye 10, along with the formwork 30, and the nearby soil 20 held by the roots 10a are pulled out of the soil 91.

Figure 10 is the fifth diagram illustrating the method for manufacturing a mulching material. After the roots 10a of the rye 10 and the soil 20 are pulled out of the soil 91 together with the formwork 30, the mulching material 1 is removed from the formwork 30 (second step). Specifically, from the state of Figure 10(a) in which the mulching material 1 has been pulled out of the soil 91, the connection between the connector 32 and the pair of flat plate members 31 is released (see the open arrow F3 in Figure 10(b)). This releases the constraint imposed by the pair of flat plate members 31, allowing the mulching material 1 to be removed from the formwork 30. This completes the mulching material 1.

FIG. 11 illustrates an example of the use of mulching material. FIG. 11 shows an example of the use of mulching material 1 in a field 90 where vegetables 93 are grown. The mulching material 1 is appropriately cut and placed to cover the soil surface 92 of the field 90. The mulching material 1 includes a plate-shaped structure 5 formed by intertwined roots 10a of rye 10 and soil 20 contained within the structure 5. The mulching material 1, which has a certain weight due to the soil 20, easily covers the soil surface 92 and prevents scattering due to wind and rain. In this embodiment, the stems 10b and leaves of rye 10 generated during the manufacturing process of mulching material 1 are laid on top of the mulching material 1 laid on the soil surface 92 of the field 90 to provide nutrients to the vegetables being grown. Alternatively, the stems 10b and leaves of rye 10 may be laid underneath the mulching material 1.

The mulching material 1 contains roots 10a of rye 10, which have the effect of keeping nematodes away from the vegetables 93. This keeps nematodes away from the vegetables 93, thereby reducing the damage caused by nematodes to the vegetables 93.

Since the mulching material 1 is produced in a field 90 where vegetables 93 are grown, the roots 10a of the rye 10 hold the soil 20 of the field 90 in place. This makes it easier for nutrients contained in the soil 20 of the mulching material 1 that covers the soil surface 92 to be supplied to the vegetables 93, thereby promoting the growth of the vegetables 93.

Since the mulching material 1 is a plant root structure formed by the roots 10a of rye 10, which is organic matter, it is easily decomposed by microorganisms. As a result, even after its use as mulching material, no residue is left in the field 90, thereby reducing the environmental impact on the field 90.

As described above, the mulching material 1 of this embodiment is formed from the roots 10a of a plant (rye 10) that is easily decomposed in the natural environment. As a result, even if the mulching material 1 becomes unnecessary or is torn into small pieces, it will decompose in the natural environment and will not remain in the field 90, thereby reducing the environmental impact on the field 90.

Furthermore, according to the mulching material 1 of this embodiment, the mulching material 1 contains soil 20 held by the intertwined roots 10a of the rye 10. As a result, the spaces between the intertwined roots 10a of the rye 10 are filled with soil 20, which can seal holes in the structure 5 and make it easier to cover the soil surface 92 of the field 90. Furthermore, because the weight of the mulching material 1 is increased, it is possible to prevent the mulching material 1 from being blown away by wind and rain. Therefore, the state in which the soil surface 92 of the field 90 is covered can be maintained for a relatively long period of time.

Furthermore, according to the mulching material 1 of this embodiment, the soil 20 contained in the mulching material 1 is the soil 20 of the field 90 in which the mulching material 1 is used. As a result, the soil 20 of the field 90 containing nutrients is used as the mulching material 1, and the nutrients contained in the soil 20 can be supplied to the vegetables 93. Furthermore, even if the roots 10a of the rye 10 decompose after use of the mulching material 1 and the soil 20 held by the roots 10a of the rye 10 remains in the field 90, it is still soil from the same field 90 and does not affect the environment of the field 90. Therefore, the environmental impact of the field 90 can be further reduced.

Furthermore, according to the mulching material 1 of this embodiment, the mulching material 1 is formed from the remaining roots 10a of rye 10, where a portion of the stems 10b has been cut off. Because the mulching material 1 is formed into a plate-like shape by the intertwined roots 10a of rye 10, it is easier to cover the soil surface 92 of the field 90 without the stems 10b.

Furthermore, the mulching material 1 of this embodiment is formed by intertwining roots 10a of rye 10, an annual plant that grows, flowers, and then dies. As a result, the rye 10 used in the mulching material 1 does not grow while it is being used as the mulching material 1. Therefore, it is possible to prevent the plants used in the mulching material 1 from damaging the environment of the field 90.

Furthermore, according to the mulching material 1 of this embodiment, green manure plants are used, which have the effect of keeping nematodes, which may cause damage to vegetables 93 in the field 90, away from the vegetables 93. This reduces the damage caused by nematodes to the vegetables 93.

Furthermore, according to the formwork 30 of this embodiment, the formwork 30 used to produce the mulching material 1 has an open outer periphery other than the portion where the connecting portion 32 is connected, and the space 30a is not sealed. This allows sufficient air and water to be supplied to the roots 10a of the rye 10 growing in the space 30a when the formwork 30 is placed in the soil 91. Therefore, the roots 10a of the rye 10 can grow sufficiently between the pair of flat plate members 31.

Furthermore, according to the formwork 30 of this embodiment, the pair of flat plate members 31 are formed so that the width Wb of the tip end 31b opposite the base end 31a connected to the connecting portion 32 is smaller than the width Wa of the base end 31a. As a result, when producing the mulching material 1 in the soil 91, the formwork 30 can be easily placed in the soil 91 by driving it into the soil 91 from the tip end 31b, which has a narrower width. This makes it easy to produce the mulching material 1.

Furthermore, according to the manufacturing method of the mulching material 1 of this embodiment, the roots 10a of the rye 10 are grown in the space 30a between a pair of flat plate members 31 placed in the soil 91, and then the roots 10a of the rye 10 are removed from between the pair of flat plate members 31. In this way, the mulching material 1 can be manufactured in the same way as growing a plant.

Furthermore, according to the manufacturing method of the mulching material 1 of this embodiment, the formwork 30 is placed in the soil 91 of the field 90 where the mulching material 1 will be used, so the mulching material 1 can be manufactured at the site where it will be used. This eliminates the need to transport the manufactured mulching material 1.

Second Embodiment
12 is a diagram illustrating an example of use of the mulching material of the second embodiment. The mulching material 2 of the second embodiment is different from the mulching material 1 of the first embodiment (FIG. 1) in the type of plants that form the structure.

The mulching material 2 of this embodiment comprises oat roots 40a and soil 20. The oat roots 40a intertwine with each other to form a structure 5 having a generally plate-like shape. The soil 20 is held in place by the oat roots 40a of the structure 5.

The example of use of mulching material 2 shown in Figure 12 shows a situation in which mulching material 2 made from oat roots 40a is used in a field 90 where Chinese cabbage 94 is grown. The relationship between Chinese cabbage 94 and oats is what is known as a companion plant. The oats that form the mulching material 2 have effects on the Chinese cabbage, such as preventing disease, repelling pests, and promoting growth. In this way, using a companion crop that is grown in a field where mulching material is used as a plant that forms the mulching material is suitable for growing crops.

As described above, the mulching material 2 of this embodiment is formed from the roots 40a of oats, which are a co-crop with the Chinese cabbage 94. As a result, the mulching material 2 can prevent diseases of the Chinese cabbage 94 and promote the growth of the Chinese cabbage 94.

<Modification of this embodiment>
The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[Modification 1]
In the above-described embodiment, the mulching material contains soil. However, the mulching material may not contain soil and may be a structure formed only from plant roots. Furthermore, although the soil contained in the mulching material is soil from the field where the mulching material is used, the type of soil is not limited to this. The mulching material may be produced in a location other than the field where the mulching material is used and brought to the field where it is used.

[Modification 2]
In the above-described embodiment, the root plants forming the structure of the mulching material are green manure plants of the grass family, such as rye and oats, which are annual plants. The root plants forming the structure are not limited to this. By using green manure plants as the root plants forming the structure, damage to crops caused by nematodes can be reduced. Furthermore, by using annual plants as the root plants forming the structure, the growth of the plants used in the mulching material on the soil surface of the field can be suppressed.

[Modification 3]
In the above embodiment, the roots of the plants that form the mulch structure are cut off from the stems. The mulch can also be used with the stems still attached. The stems can also be used as a source of nutrients for the crops.

[Modification 4]
In the above-described embodiment, the formwork for producing the mulching material includes a pair of flat plate members. However, the configuration of the formwork is not limited to this. For example, the formwork may be configured to produce a mulching material having a curved shape that conforms to the shape of the ridges in the field.

[Modification 5]
In the method for producing a mulching material, rye seeds are sown in the first embodiment, and oat seeds are sown in the second embodiment. However, in the method for producing a mulching material, a mixture of seeds of different varieties may be sown, such as a combination of rye seeds and oat seeds. For example, by sowing a mixture of seeds of a variety whose roots tend to grow depthwise and seeds of a variety whose roots tend to grow horizontally in the soil from which the mulching material is produced, the mulching material structure can be formed in a roughly mesh-like shape. This makes it easier to retain the soil, and therefore makes it easier to further cover the soil surface with the mulching material.

[Modification 6]
In the first embodiment, the stems 10b and leaves of the rye 10 generated in the manufacturing method of the mulching material 1 are laid so as to cover the soil surface 92 of the field 90, similar to the mulching material 1. As in the second embodiment, it is not necessary to cover the soil surface 92 with the cut stems 10b and leaves (see FIG. 10).

This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

1, 2... Mulching material 90... Field 92... Soil surface 10... Plant 10a... Root 10b... Stem 20... Soil 30... Formwork 30a... Space portion 31... Flat plate member 31a... Base end portion 31b... Tip portion 32... Connection portion Wa, Wb... Width

Claims (2)

A method for producing mulching material, comprising:
a first step of growing plant roots between a pair of flat plate members buried in soil;
and a second step of removing the roots of the plant grown in the first step from between the pair of flat plate members.
A method for producing mulching material, characterized by: The method for producing a mulching material according to claim 1 further comprises:
A third step is provided before the first step, in which the pair of flat plate members is placed in soil of a field in which the mulching material is used.
A method for producing mulching material, characterized by: