Soil erosion mitigation method and diversified cultivation method

Abstract

To provide a method capable of reducing soil runoff while cultivating mushrooms. [Solution] A method for reducing soil erosion includes placing a fungal bed inoculated with mushroom fungi so that it is in direct contact with soil, and cultivating mushrooms in the fungal bed.

Description

[Technical Field]

[0001] The present invention relates to a method for reducing soil erosion and a method for integrated cultivation. [Background technology]

[0002] Soil erosion caused by rainfall is increasing in Japan and other tropical and subtropical regions of Asia. Soil erosion is particularly likely to occur in areas where forests have been converted into farmland and on sloping land. For example, red soil runoff is a problem in subtropical islands such as Okinawa Prefecture.

[0003] Patent Document 1 discloses a soil erosion prevention method in which an organic substrate is added to the soil to promote the formation of mycelia of microorganisms that can form mycelia that survive in the soil, thereby allowing the mycelia to grow on the soil surface and / or the soil surface layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-282312 Summary of the Invention [Problem to be solved by the invention]

[0005] Countermeasures for preventing red soil runoff in Okinawa Prefecture include the grass mulch method, in which cut millet leaves are spread on fields; the leaf rubble packing method, in which bundles of sugarcane leaves are spread between fields and waterways; the green belt method, in which a vegetated belt (green belt) is established around fields; and the stubble cutting method, in which sugarcane stubbles are left in place after the sugarcane harvest to shorten the period of time that the fields are bare.

[0006] However, these methods rely on the self-help efforts of each farmer, and implementing these runoff prevention measures does not directly translate into income for the farmer. Therefore, these runoff prevention measures have not been widely adopted. Furthermore, the method described in Patent Document 1 is not intended for mushroom (fruit body) cultivation.

[0007] Conventional mushroom cultivation methods generally involve cultivation on mushroom beds in temperature- and humidity-controlled indoor facilities or outdoor cultivation on logs, but no method has been adopted where mushroom beds are directly placed in the soil outdoors.

[0008] An object of the present invention is to provide a method that can reduce soil erosion while cultivating mushrooms. [Means for solving the problem]

[0009] The present invention relates to, for example, the following [1] to [3]. [1] A method for reducing soil erosion, comprising placing a fungal bed inoculated with mushroom fungi so that the fungal bed is in direct contact with the soil, and cultivating mushrooms in the fungal bed. [2] The method according to [1] in a crop cultivation area. [3] A method for the integrated cultivation of agricultural crops and mushrooms, which includes cultivating mushrooms on a bed inoculated with mushroom fungi in a crop cultivation area by placing the bed in direct contact with the soil. [Effects of the Invention]

[0010] The present invention provides a method that allows for the cultivation of mushrooms while reducing soil erosion. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a graph showing the fruit body yield in a mushroom field cultivation test. [Figure 2] 1 is a graph showing the amount of soil runoff in each test plot in a soil runoff test. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the embodiments for carrying out the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0013] [Methods for reducing soil erosion] One embodiment of the present invention relates to a method for reducing soil erosion, which includes placing a fungal bed inoculated with a mushroom fungus in direct contact with soil, and cultivating mushrooms in the fungal bed.

[0014] Although the mechanism by which soil erosion can be reduced by the soil erosion reduction method according to this embodiment is unclear, it is thought that the fungal bed physically blocks the eroded soil, similar to the state in which sandbags are placed as a retaining wall. Furthermore, although the fungal bed is lighter than sandbags, it is thought that mycelium extends into the soil from the fungal bed placed directly on the soil, increasing its ability to hold the soil in place during precipitation. Furthermore, the fungal bed itself also has the effect of protecting the soil from precipitation.

[0015] The mushrooms cultivated in the method according to the present embodiment may be commercially valuable mushrooms for food or medicinal use. The mushrooms may be, for example, saprophytic or mycorrhizal fungi, and may belong to the Ascomycota, Basidiomycota, or the like. The mushrooms may be, for example, mushrooms that grow naturally in cool, temperate, subtropical, or tropical regions. The mushrooms may typically belong to the Auricularia genus, such as Auricularia auricularia and Auricularia auricularia.

[0016] Conventional mushroom cultivation methods generally use sterile mushroom beds in rooms where humidity is controlled, whereas the method for reducing soil erosion according to the present embodiment allows mushroom beds to be placed directly in outdoor soil, enabling mushrooms to be cultivated to a harvestable level even in conditions where temperature and humidity are not controlled, and also reducing soil erosion due to precipitation compared to when mushroom beds are not placed.

[0017] The fungal bed used for mushroom cultivation can be produced by conventional methods. Specifically, it can be produced, for example, by the following method. First, a medium is prepared by mixing a wood substrate such as sawdust or bagasse with ingredients such as bran, rice bran, lime, and other nutrients, and water. The medium may also contain other substrates made of materials other than wood, such as resin. The obtained medium is filled into a container such as a bag, box, or bottle. After filling, it may be compressed and formed into any shape. The medium is then sterilized. The sterilization may be, for example, heat sterilization. Heat sterilization may be performed under pressure. Heat sterilization is performed, for example, at 121°C and 2 atmospheres for 30 minutes. The composition, moisture content, pH, etc. of the fungal bed can be appropriately changed depending on the type of mushroom being cultivated. Commercially available fungal beds can be used.

[0018] The mushroom fungus is inoculated into the cooled fungal bed after heat sterilization. The inoculation of the mushroom fungus into the fungal bed is preferably carried out in a sterile room. After the mushroom fungus is inoculated into the fungal bed, it is cultured using standard methods. Culture conditions may be set appropriately depending on the type of mushroom to be cultivated. Cultivation can be carried out, for example, in a room where conditions such as temperature, humidity, brightness, and carbon dioxide concentration are controlled. The culture period may be, for example, about 1 to 6 months. It is desirable to allow mycelium to sufficiently spread over the substrate of the fungal bed through culture. Using a fungal bed with sufficient mycelium spread is preferable because it can increase resistance to harmful bacteria such as mold. Whether mycelium has spread over the substrate of the fungal bed can be confirmed visually.

[0019] A fungal bed in which the mushroom fungus has been sufficiently cultivated and the mycelium has spread is placed on the soil at the location where the soil erosion reduction method according to this embodiment is to be carried out. The fungal bed is placed directly on the soil where soil erosion reduction is desired. Specifically, it is sufficient that the wood substrate that forms the fungal bed and that has been inoculated with the mushroom fungus is in direct contact with the soil. The surface of the fungal bed may be covered with vinyl or the like, but at least a portion of the surface that comes into contact with the soil should be exposed so that it can come into direct contact with the soil.

[0020] The location where the fungal bed is installed is not particularly limited as long as the fungal bed can be installed directly in the soil and the reduction of soil erosion is desired. The fungal bed installation location may be on a slope or flat ground. If the installation location is on a slope, it is preferable because it is more effective in reducing soil erosion caused by precipitation, etc. The installation location of the fungal bed may be, for example, between the rows of agricultural crops to be cultivated in a mixed cultivation, or may be bare ground without vegetation.

[0021] The shape and size of the fungal bed may be any shape commonly used for mushroom cultivation. The shape of the fungal bed may be, for example, a rectangular parallelepiped, a cylinder, a cone, etc., and when packed in a bag, the shape may correspond to the bag. The size of the fungal bed may be, for example, a size of 100 cm2 or less, in which the surface area in direct contact with the soil is 100 cm2 or less. 2 More than 500cm 2 or more, or 1000cm 2 may be greater than or equal to 10,000 cm 2 Below, 5000cm 2 or less than 1000cm 2 The height of the fungal bed may be, for example, 5 cm or more, 10 cm or more, 20 cm or more, or 30 cm or more. From the viewpoint of maintaining moisture by capillary action, the height of the fungal bed is preferably 40 cm or less, and may be 30 cm or less, or 20 cm or less.

[0022] The fungal beds do not need to be installed over the entire surface of the soil where soil erosion reduction is to be performed, but rather can be installed at intervals with appropriate passages of the above shapes and sizes. The installation area of ​​the fungal beds in the soil can be, for example, 10% or more per unit area, and may be 100% or less, 80% or less, 60% or less, 40% or less, or 20% or less.

[0023] The mushroom bed may be installed in direct sunlight (under open skies) or in the shade of other plants or agricultural crop leaves if they are overgrown. The degree of openness of the mushroom bed installation location may be 0 to 100%, and may be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%. In this specification, the degree of openness refers to the proportion of the sky to the entire image when photographed in the zenith direction with a 180-degree fisheye lens. The ability to cultivate mushrooms under open skies without providing shade is an unexpected advantage compared to conventional mushroom mushroom bed cultivation methods.

[0024] The degree of openness may be adjusted artificially using cheesecloth or diversified crop cultivation, but in the method according to this embodiment, mushrooms can be cultivated either in full open air or in the shade, so there is no need to adjust the degree of openness.

[0025] The type of soil on which the method according to the present embodiment is implemented may be, for example, red-yellow soil, dark red soil, lowland soil, brown forest soil, andosol, immature soil, etc. Red-yellow soil or dark red soil is preferred because of its high effect on reducing soil erosion. Okinawa Prefecture is home to various types of soil, such as Shimajiri maaji, Kunigami maaji, Jāgaru, and Kucha. The type of soil on which the method according to the present embodiment is implemented may be, for example, Shimajiri maaji, Kunigami maaji, Jāgaru, or Kucha.

[0026] The region in which the method for reducing soil erosion according to this embodiment is carried out may be, for example, a cool temperate, subtropical, or tropical region, with a subtropical or tropical region being preferred. The region in which the method for reducing soil erosion according to this embodiment is carried out may have, for example, a temperature range of 10 to 35°C. The region in which the method according to this embodiment is carried out is preferably one in which, for example, morning dew occurs. In a climate or region in which morning dew occurs, the surface of mushrooms (fruiting bodies) becomes wet, and therefore humidity suitable for mushroom growth can be maintained without temperature and humidity control, which is preferred.

[0027] After the mushrooms have grown to a suitable size, the mushrooms (fruiting bodies) can be harvested at any time. The mushroom bed after harvesting can be reused or returned to the soil as waste fertilizer.

[0028] [Combined cultivation method] One embodiment of the present invention relates to a method for the integrated cultivation of agricultural crops and mushrooms, which comprises cultivating mushrooms on a fungal bed inoculated with a mushroom fungus in a field for cultivating agricultural crops, by placing the fungal bed in direct contact with soil.

[0029] When cultivating a single crop, measures such as laying mulch are required to prevent soil erosion between the rows. On the other hand, the composite cultivation method according to the present embodiment makes it possible to simultaneously cultivate any crop and mushrooms while reducing soil erosion between the rows of the crops.

[0030] In the combined cultivation method according to this embodiment, mushrooms can be cultivated under open skies or in the shade. Therefore, even if the crops cultivated together with the mushrooms are underdeveloped and the air above the mushroom bed is open, or even if the crops grow and create shade above the mushroom bed, mushrooms can be harvested in either case.

[0031] The crops to be cultivated in combination with mushrooms can be appropriately selected from crops that can be grown in the area where the combined cultivation method of this embodiment is carried out. The crops may be, for example, vegetables or fruits, and typically may be pineapples, sugarcane, etc.

[0032] In the combined cultivation method according to this embodiment, the above-described aspects of soil erosion reduction can be applied to specific aspects such as mushrooms, fungal beds, fungal bed installation locations, installation methods, soil, and regions.

[0033] The soil erosion reduction method and integrated cultivation method according to this embodiment are not necessarily efficient as a method for cultivating mushrooms, but they are significant in that they allow for the economic benefit of harvesting mushrooms while reducing soil erosion in a cost-effective and simple manner in areas where other agricultural crops are cultivated or bare land. [Example]

[0034] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to the following examples.

[0035] [Mushroom field cultivation test] The field cultivation experiment of mushrooms was carried out in an outdoor field at the Tropical Islands Research Center of the Japan International Research Center for Agricultural Sciences on Ishigaki Island, Okinawa Prefecture. The test fungus used was a strain of Auricularia polytricha collected on Ishigaki Island.

[0036] The mushroom beds used were a sawdust bed made by mixing sawdust from oak trees with rice bran, and a bagasse bed made by mixing bagasse and rice bran. Specifically, the beds were prepared as follows. For the sawdust bed, oak sawdust and rice bran were mixed in a mass ratio of 5:1, and the moisture content was adjusted to 65% (pH 5.6). For the bagasse bed, dried bagasse was soaked in water to hydrate it, and then mixed with 3% rice bran, 1% lime, 0.5% urea, 1% ammonium sulfate, and 2% superphosphate based on the mass of the hydrated bagasse. The mixture was turned over for 7 days and composted for 48 days (pH 6.0). Each was packed into a polypropylene mushroom cultivation bag (2.5 kg size), sterilized in an autoclave at 121°C for 30 minutes, and then infused with 10 g of Auricularia spp. The sawdust beds were cultured at a room temperature of 24°C ± 2°C and a relative humidity of 80% for 120 days, and the bagasse beds were cultured under the same conditions for 42 days.

[0037] Three test areas with different levels of sky openness were prepared: a dark area (sky openness 30%), a medium area (sky openness 60%), and a bright area (sky openness 100%). In the dark and medium areas, steel frames were erected around the test area, and cheesecloth was stretched parallel to the ground at a height of 2 m from the ground. The sky openness was adjusted to 30% and 60%, respectively, by increasing or decreasing the number of cheesecloth sheets. The sky openness is the ratio of the sky to the whole sky when photographing with a 180-degree fisheye lens facing the zenith.

[0038] Each test plot was 10m square, and a 5m square mushroom bed area was set up slightly north of the center of the test plot. In the mushroom bed area, the mushroom beds were placed directly on the soil at 50cm intervals. The cultivation period was from May 27 to August 31, 2022. No artificial watering was performed during the cultivation period.

[0039] All fruiting bodies of Auricularia auricularia obtained during the above period were harvested. Figure 1 shows a graph of the average weight of Auricularia auricularia fruiting bodies per fungal bed harvested in each test plot. Error bars indicate standard error. Tests were performed using the Tukey-Kramer method. * indicates a p-value of less than 0.01, and ** indicates a p-value of less than 0.05.

[0040] Fruiting bodies were harvested in all test plots with air openings of 30%, 60%, and 100%. Fruiting bodies were particularly harvestable under the bright, dry conditions of 100% air opening. Although a higher yield was achieved with a fungal substrate containing sawdust than with a substrate containing bagasse, sufficient fruiting bodies were also cultivated with a substrate containing bagasse.

[0041] [Soil erosion test] The soil erosion test was conducted on a sloping field within the Japan International Research Center for Agricultural Sciences (JIRCAS) on Ishigaki Island, Okinawa Prefecture. Each lane in the sloping field measured 4 m wide and 10 m deep, with a 3-degree slope. The soil was Kunigami margi, a type of soil typical of Okinawa Prefecture. Before the test, the field was rotary-rolled to restore it to normal agricultural soil. Hand weeding was performed as needed to prevent soil erosion due to overgrowth of weeds. The test was conducted over a period of approximately 10 months, from September 6, 2022, to June 22, 2023. Total precipitation during the test period was 2122 mm. Precipitation data was collected from the meteorological observation station at the JIRCAS Tropical and Island Research Center.

[0042] Three types of test plots were established: a hanging-type cheesecloth bed area, a full-sun open-air bed area, and a bare area under full open air. In the bed-installed areas, six rows of eight beds were installed in each lane, with one bed installed every 50 cm in a staggered pattern. The area coverage of the bed-installed areas was approximately 16%. The same type of bed was used as the bagasse bed in the mushroom cultivation test described above. In the hanging-type cheesecloth area, hanging-type cheesecloth (Dio Chemical Co., Ltd., Dioflara, approximately 60 cm in the hanging direction) was installed at 30 cm intervals at a height of approximately 2 m from the ground to shade the beds (openness approximately 30%). In the full-sun open-air area, no cover was placed above the beds. In the bare area under full open air, no beds were installed and no cover was placed above the beds.

[0043] At the bottom of the sloping field, soil collection boxes were installed in each lane to collect and settle soil that had run off after rainfall. The amount of soil runoff was calculated by confirming that the rain had completely stopped, recovering the soil that had accumulated in the collection boxes, drying it in an oven, and measuring the dry weight of the soil. One lane was used for the area with suspended cheesecloth mushroom beds, and two lanes were used for the area with mushroom beds under open skies and the bare area. The average amount of soil runoff per lane over the entire period is shown in the graph in Figure 2.

[0044] In the areas where mushroom beds were installed, it was confirmed that the amount of sediment runoff was reduced compared to the bare areas where no mushroom beds were installed, both when shaded with cheesecloth and when exposed to the open sky.

Claims

1. Placing the mushroom bed inoculated with the mushroom fungus so that it is in direct contact with the soil; and cultivating mushrooms in said fungal bed.

2. 10. The method of claim 1 in a field where crops are grown.

3. A method for the combined cultivation of agricultural crops and mushrooms, comprising cultivating mushrooms on a fungal bed inoculated with mushroom fungi in a field for cultivating agricultural crops by placing the fungal bed in direct contact with soil.

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