JPH02256718A - Bedrock slope face tree-planting material and bedrock slope face tree-planting method - Google Patents

Abstract

PURPOSE:To quicken the proceeding from an initial phase to a transient phase by compounding organic material in a specified ratio to the soil particle of the particle size of a specified value or less, of the mineral soil improving material of a large cation exchange capacity in a specified ratio to the organic material, and by spraying a bedrock slope face with the compounded material. CONSTITUTION:As the material of artificial culture medium, soil and organic material, erosion-proof particle bonding agent and chemical fertilizer, and the seeds of plants are mixed with each other at least, and a bedrock slope surface 2 is sprayed with the material, and slope face tree-planting is promoted. Then, soil particles sieved in the particle size of 4mm or more on a stratum among soil removed by civil engineering works are compounded of the organic material, in the capacity ratio of 0.4 to 0.5, to the capacity of 1 of the organic material, and the soil is compounded of mineral material having a large cation exchange capacity, in the capacity ratio of 0.05 to 0.1, to the capacity of 1 of the mineral material, and the bedrock slope face 2 is sprayed with the compounded material. As a result, water-repellency is suppressed, and nutritious substance retaining capacity and the biosystem of soil microbes are kept, and slope face vegetation can be promoted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rock slope greening material and a rock slope greening method that are sprayed onto a rock slope to green the slope.

[Prior Art] As is well known, when constructing golf courses, large-scale parks, residential complexes, industrial parks, roads, etc., greening materials are sprayed onto rock slopes that have become devoid of vegetation due to the construction work, creating artificial culture media. The technology to create trees and carry out greening is already known.

Such conventional greening materials include at least soil, organic materials such as bark compost or peat moss, and polymeric resins such as Cricoat C-710 and CP-750 (trade names).
, C-402, a mixture of chemical fertilizer and plant seeds is known, and if necessary mineral materials such as perlite can be added to increase water retention. I'm letting you do it. Greening materials are determined based on the hardness index of the rock slope, the way in which cracks form, the degree of consolidation and weathering of the bedrock, etc.
The thickness of the spraying was determined by taking into account the annual rainfall and altitude of the construction site, the slope of the rock slope, etc. In this way, seeds of the sprayed artificial medium will germinate over time, and plants will grow and cover the slope.

[Problems with the prior art] In general, when growing plants, once the land is stabilized, vegetation succession progresses over time.In the initial phase of 0 to 7 years, herbaceous plants Shrubs and bushes grow in the transitional phase of 20 years, and trees grow in the peak phase of 20 to 100 years or more. Therefore, it is necessary for the vegetation growing on the artificial culture medium sprayed on the rock slope to undergo the above-mentioned transition naturally.

However, in the prior art, the following problems occurred in order to prevent erosion of slopes without vegetation cover.

(1) Seeds added to the artificial medium to be sprayed include:
The main focus is on exotic herbaceous species (such as turf grass) that grow quickly but tend to decline when the nutrients in the culture medium become low, and the species that are native to Japan are slow-growing initially but are hardy and long-lasting. In the early stages, the native Japanese herbaceous species that are suited to Japan's climate will be overwhelmed by the vigorous growth of non-native herbaceous species, and establishment will be difficult or extremely slow.

Therefore, the initial phase of vegetation succession is prolonged, the transition to the transitional phase is delayed, and because the initial phase is prolonged, the replacement of native Japanese herbaceous species due to the decline of exotic herbaceous species cannot keep up.
As a result, the degree of coverage by slope vegetation decreases, and erosion prevention of the culture medium becomes insufficient.

(2) Since standards for the soil-like properties of the medium have not been established, plants must continue to grow mainly using the limited thickness of the medium on the slope. Not necessarily compatible with vegetation maintenance and succession.

[Means for Solving the Problems] Therefore, an object of the present invention is to provide a bedrock slope greening material and a bedrock slope greening method that prevent erosion of the culture medium and facilitate the transition of vegetation. .

[Findings of the Invention] The present inventors collected culture medium from slopes of construction sites in different geological areas such as granite, andesite, basalt, sandstone, left and right, and found that it is thought to be closely related to plant growth. requirements,
In other words, the hydrogen ion concentration (pH) of the medium, the electrical conductivity indicating the salt content, the effective water retention capacity, which is water that plants can easily use, the cation exchange capacity, which is the ability to retain plant nutrients, and the medium content. We analyzed the viable counts of soil microorganisms that control the circulation of plant nutrients, as well as the ``bacterial count/filamentous fungi count'' ratio and the ``bacteria count/actinobacteria count'' ratio, which are indicators for determining the state of the microbial ecosystem. As a result, it was found that the minimum soil properties that an artificial culture medium must have when sprayed on a rock slope at a thickness of 51 are as follows.

pH: 6.5 to 7.3 (neutral range) Electrical conductivity: 1 ms (millisiemens)/clI or less Easy effective water retention capacity Crab 20 m++ or more Cation exchange capacity: 10 eq (equivalent)/rrr or more Soil microbial viable bacteria Bacterial count: 5 x 10'/g or more Bacteria count Filamentous fungus count: 50 to 500 Bacteria count/actinomycete count = 1 to 10 Others: High resistance to water erosion However, in the case of conventional technology, the above The cation exchange capacity was insufficient, especially the cation exchange capacity.

[Means for Solving the Problems] According to the rock slope greening material of the present invention, at least soil, an organic material, a particle binder for erosion prevention, a chemical fertilizer, and a plant seed are mixed as materials for an artificial medium. In the bedrock slope greening material that is sprayed onto the bedrock slope, the soil has a particle size of 4, which is obtained by sieving the surface soil of the soil distributed at or near the civil engineering work site.
+ m or less soil particles, the mixing ratio of which is a volume ratio of 0.4 to 0.5 to 1 volume of organic material, and a mineral soil improvement material having a large cation exchange capacity is equal to or less than the volume of organic material. 1 to 1 at a volume ratio of 0.05 to 0.1.

Further, according to the rock slope greening method of the present invention, at least soil, an organic material, a particle binder for erosion prevention, a chemical fertilizer, and a plant seed are mixed as materials for an artificial medium, and the mixture is sprayed onto the bedrock slope. In the slope greening method, at least the surface soil of the soil removed by civil engineering works is
The sieved soil particles are sieved into soil particles with a volume ratio of 0.4 to 0.5 relative to the organic material, and a mineral soil conditioner having a large cation exchange capacity is mixed with the organic material. The material is mixed with a volume ratio of 0.05 to 0.1, and the mixed material is sprayed onto the rock slope.

[Effect] Since locally generated soil from the civil engineering work site or its surroundings is used, it contains a relatively large amount of seeds of native species suitable for the site, promoting the growth of native species and increasing the number of seeds. As a result, transitions occur smoothly. The reason why the soil was sieved to 4w or less is that locally generated soil tends to adhere to organic materials. That is, at 4W or more, the spray will fall off after drying.

Peat moss or park compost is used as the organic material. If the mixing ratio of locally generated soil is less than 0.4 by volume to 1 part of organic material, the amount of seeds entering the locally generated soil will be small and the transition will be delayed. Further, as will be described later, if the formation of organic-inorganic composite colloid is small, or if it is 0.5 or more, erosion will occur easily and the soil will easily fall off. That is, from the point of view of seeds, it is preferable to have as much locally grown soil as possible, but if there is too much soil, the erosion resistance and effective moisture retention capacity of the medium will decrease. Therefore, the capacity ratio is 0.4~
0.5.

Generally, many locally generated soils have a low cation exchange capacity, so in the present invention, a mineral soil conditioner having a large cation exchange capacity, such as zeolite, vermiculite, bentonite, etc., is mixed. If the blended volume ratio to the organic material is less than 0.05, a cation exchange capacity of 10 eq/rrf or more cannot be obtained, and sufficient plant nutrient retention ability cannot be obtained. If the volume ratio is 0.1 or more, it is economically preferable. Therefore, the capacitance ratio is set to 0.05 to 0.1.

According to the present invention, the following points are improved over the conventional technology: (1) In a culture medium made mainly of organic materials, when the culture medium begins to dry after a period of no rain, the property of water repellency (difficult) Even if there is less than a few millimeters of rainfall,
The medium absorbs and retains less of this water, reducing the water supply to the plants. This is one of the causes of suppressing plant growth. A culture medium containing locally generated soil suppresses this watery property, so even a small amount of rainfall of 1 to 2 cm can adsorb and retain water well.

(2) The cation exchange capacity of an artificial culture medium made by blending organic materials and locally generated soil without blending a mineral soil conditioner with a large cation exchange capacity varies in the range of about 7 to about 14 eq/nf. If the locally generated soil is sandy or loamy soil with a small cation exchange capacity, the cation exchange capacity is 1.
It becomes 0 eq/rrr or less, which does not meet the specified criteria for soil properties of an artificial medium. When a mineral material with a large cation exchange capacity, such as zeolite, is blended with an organic material at a ratio of 0.05 to 0.1, the cation exchange capacity increases from 3.75 to 7.5 eq/d. Therefore, in an artificial medium containing organic materials, locally generated soil, and zeolite, the cation exchange capacity is 10 eq/rrr no matter what type of locally generated soil is used.
With the above, the nutrient retention ability of the artificial medium is guaranteed.

(3) Park compost (organic material), which is the main material for artificial culture media, contains a considerable amount of salt due to the manufacturing process.
When a culture medium is mainly made of organic materials, as it dries out, the salt concentration in the water in the culture medium tends to increase, which can inhibit plant growth. However, in a medium mixed with locally grown soil, the salt concentration of the water in the medium increases only slightly, so plant growth is not inhibited.

(4) From the perspective of continuous supply of plant nutrients from the medium, the active fraction of the medium (those that contribute to plant growth)
However, it is a well-established theory in the field of soil science that a medium composed of organic and inorganic composite colloids is superior to a single organic colloid or an inorganic colloid alone as a medium for plant growth. Unlike when soil is not mixed, organic and inorganic complex colloids are formed over time, and soil agglomeration in the medium progresses. This is due to the continuous flow of nutrients from the medium to plants. This is extremely advantageous in terms of supply. In other words, in the case of a culture medium on a bedrock slope, fertilizer is also mixed in when spraying the artificial medium, but the nutrients derived from the fertilizer disappear within one to two years after spraying, and after that, the nutrients derived from the fertilizer disappear. Due to the ability of the culture medium to circulate nutrients (nutrients are returned to the soil once it withers), nutrients must be constantly supplied to the plants. Soil microorganisms control the nutrient circulation in this medium. As soil agglomeration in the medium progresses, suitable habitats for soil microorganisms increase, allowing a variety of soil microorganisms to live in a well-balanced manner in the medium, resulting in a healthy soil microbial ecosystem. will be maintained. Therefore, the continuous supply of nutrients from the culture medium to the plants progresses without any hitch.

(5) If the soil properties of the artificial culture medium sprayed onto the rock slope are defined and the main materials of the artificial culture medium are a mixture of organic materials and locally generated soil, then (1), (2), (3) above, As the improvement as a vegetation medium described in (4) progresses, these effects collectively reflect the maintenance of slope vegetation and the progression of succession.

[Preferred Embodiment] In carrying out the present invention, any known particle binder, chemical binder, and exotic plant seed for erosion prevention can be used. In addition, if there is insufficient surface soil as locally generated soil,
The top soil on the next layer can be used.

[Example] The present invention will be described in detail below with reference to the drawings.

Figure 1 shows the cross-sectional form of a typical soil.Herbaceous plants P grow on the ground surface S, and the layer A, which is the layer immediately below the ground surface S, is surface soil, or so-called black soil. This is the area where plant roots mainly grow, where a large number of soil microorganisms live, and its thickness is usually about 10,011 mm. The B layer below is the next layer, and is made up of weathered rocks that turn into soil, but it is rich in minerals and lacks plant nutrients. It is the base material of the A layer and B layer. The depth from the ground surface S to the bottom surface of the 0th layer is not constant, but is approximately 100 an. The R layer below the 0 layer is a rock layer that has not yet been strongly weathered, and the G layer below it is a rock layer that has been weakly weathered.

In implementing the present invention, first, the soil in the shaded area indicated by reference numeral 1 in FIG. 2 is removed by civil engineering work, and the slope 2 is exposed by the civil engineering work.

Native woody plants T and herbaceous plants P grow on the ground surface S.

Next, as shown in FIG. 3, a greening material according to the present invention is sprayed onto the slope 2 to form a culture medium 3. Usually, the thickness thereof is Sa.
It is in position a. After a few days, the seeds mixed with the greening agent germinate on the surface of the sprayed soil and grow as herbaceous plants 4, but these herbaceous plants 4 are initially divided into exotic plants and native plants. The native species gradually become dominant, establishing the initial phase of vegetation succession and hastening the transition to the transitional phase. The transition to this transitional phase begins in about four months.

As a result, after several years, as shown in FIG. 4, native species become dominant as the herbs 4 growing in the medium 3, and a relatively large number of shrubs 5 also grow.

[Comparative example] Figure 5 shows the vegetation transition according to the conventional technology.
As shown in the figure, after several years have passed, foreign species still have priority as the herbaceous plants 4 that have grown on the medium 3, and therefore the establishment of shrubs 5 is slight.

This means that the transition to the transient phase is delayed.

[Effects of the Invention] As described above, according to the present invention, the progression from the initial phase to the transient phase begins in more than four months, which is much shorter than several years in the conventional example.

Even if the short-lived non-native herbaceous species begin to decline, the long-lived native herbaceous species will continue to grow even more vigorously, so the medium on the slope will not be eroded and the transition of vegetation will be even faster. be accelerated. As a result, the artificial vegetation on the bedrock slope rapidly approaches its natural state and blends into the surrounding natural landscape, making the bedrock slope more stable and aesthetically pleasing.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of the cross-sectional form of natural soil, Fig. 2 is an explanatory diagram showing an example of the implementation of the present invention, and Fig. 3 is a diagram showing an example of the implementation of the present invention. FIG. 4 is an explanatory diagram showing the transition of vegetation after several years, and FIG. 5 is an explanatory diagram showing the transition of vegetation according to a conventional example. 1... Parts removed during civil engineering work 2... Slope 3... Culture medium 4... Herbs 5... Shrubs

Claims (2)

[Claims] (1) In a bedrock slope greening material that is sprayed onto a bedrock slope by mixing at least soil, organic materials, a particle binder for erosion prevention, chemical fertilizer, and plant seeds as materials for the artificial medium,
The soil is soil particles with a particle size of 4 mm or less obtained by sieving the surface soil of soil distributed at or near civil engineering construction sites, and the mixing ratio is 0.4 to 0.4 mm in volume to 1 volume of organic material. 5 and a mineral soil improvement material having a large cation exchange capacity is blended at a volume ratio of 0.05 to 0.1 to 1 volume of the organic material. Greening material. (2) In a bedrock slope greening method in which at least soil, organic materials, particle binders for erosion prevention, chemical fertilizers, and plant seeds are mixed as materials for an artificial culture medium and sprayed onto the bedrock slope, the materials removed by civil engineering work. At least the surface soil of the soil is sieved into soil particles with a particle size of 4 mm or less, and the sieved soil particles are mixed with organic material at a volume ratio of 0.4 to 0.
．． 5 and a mineral soil conditioner with a large cation exchange capacity to the organic material at a volume ratio of 0.05 to 0.1.
A rock slope greening method characterized by blending the above ingredients and spraying the blended material onto the rock slope.