JP2002315432A - Culture medium for greening rooftop and ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the culture medium for the greening a rooftop and a ground part of a building requiring less time and labor for cultivation and facilitating the water control without elution of waste water, by finding out the optimum physical properties and grain size of a solid culture medium for greening. SOLUTION: This culture medium for greening the rooftop and ground is characterized in that the culture medium is composed of a granular pumice having a smaller bulk specific gravity than that of usual soil and 0.3-0.8 bulk specific gravity of pumice. The granular pumice preferably has 0.1-1.0 cm/s saturation water permeation coefficient and 5-60 cm/s air permeation coefficient in a dry sample and a wet sample.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a culture medium for rooftop and above-ground greening, and more specifically, to save water and water on a rooftop and above-ground part of a building by using a facility cultivation method. The present invention relates to a medium for plant cultivation suitable for cultivation under resource saving. Further, the present invention relates to a cultivation medium for rooftop and above-ground greening, which can cultivate a value-added agricultural crop, for example, because the moisture content of the medium can be adjusted, so that the sugar content can be increased in tomatoes and melons among fruits and vegetables.

[0002]

2. Description of the Related Art In the past hundred years, the average temperature in Tokyo has been 2.9.
° C also rose. "Heat island phenomenon" in such a downtown area
The Tokyo Metropolitan Government revised the Nature Conservation Ordinance and decided to require the rooftop greening of newly renovated buildings for the first time in Japan (December 20, 1999). This mandates that 20% of the available rooftop space be planted with trees, turf, flowers and the like. Conventionally, there are examples of planting trees on the roof of a building, which is a building, and planting trees, and in large buildings, creating gardens on the roof, etc., planting trees on the soil adds a large weight. However, since it causes water leakage from the roof and damages the building, it was limited to small privately owned buildings, and when building a garden, it was limited to those related to business. For that reason, there were not so many special techniques for rooftop greening. Recently, not only buildings but also large-scale buildings such as artificial ground have been built, and buildings have been built on top of this.In this case, not only rooftop greening but also soil on the ground part of the building It is necessary to form a green area in a concrete part where there is no space, but it is at this level that soil is simply filled in that part. Recently, private gardens have developed an eco-garden system that converts the rooftop of a building into a vegetable field, and the building has grown unsuitable vegetables, and has succeeded in growing grass and flowers.

[0003] As an excellent institutional cultivation method for high-quality vegetables and fruit trees, there is a hydroponic cultivation method. Hydroponic cultivation methods are classified into a solid medium method and a non-solid medium method. The solid medium method includes, for example, sand culture, gravel culture, charcoal culture, and the like. This is a method in which sand, gravel, charcoal and the like are spread to form a culture medium, and nutrient water and the like are constantly sprinkled there.

[0004]

By the way, in order to prevent the heat island phenomenon in the city and to plant trees on the roof in order to green the roof of all the buildings to be constructed, the roof of the building has to be planted as before. Waterproofing, putting soil there and planting trees can be a very difficult problem. Especially in high-rise buildings, although many lightweight materials are used to reduce the weight on the pillars, putting heavy soil on the roof causes problems in the strength of the building and also in earthquake resistance It will cause problems. Not only for buildings inside buildings, but for large structures, the surrounding soil is removed, and because of the construction of underground parking lots, the surrounding area is often made of concrete. However, in that case, it is necessary to green the ground part from the viewpoint of the landscape. In this case, since the lower part is a concrete part, there are problems such as waterproofing and weight, and it is not easy to green.

That is, when the soil for planting plants is held on the rooftop or the ground portion of the building in order to green the rooftop or the ground portion of the building, a problem is imposed on the building by the weight of the soil. And when supplying water or culture solution for cultivating plants planted on the soil held, if the supply of water etc. is too large or heavy rain falls, the ceiling of the building under the soil There is a problem that water leakage occurs in the part and the weight of the soil further increases, so that the burden on the building becomes more serious. To prevent this, the strength of the building must be further increased. It is also necessary to further strengthen the waterproof structure of the rooftop of the building.
In addition, the rooftop of the building is more sunny than the ground, the heat capacity of the whole building is large, and the wind is strong, so that the soil is adjusted to conditions suitable for plant growth, It was difficult to set supply conditions and the like. In the conventional solid medium method, there was a problem that cultivation was extremely troublesome. Plants were less likely to root on media such as sand and gravel, resulting in poor harvest rates. In addition, the plants were susceptible to disease, and they were unable to keep an eye on constant monitoring. Further, there is a problem that water management is difficult and a large amount of waste water is often discharged, or conversely, a shortage of water occurs.

[0006] At present, various types of culture media for light-weight and excellent water retention for rooftop greening are being studied as media for facility cultivation for rooftop and above-ground greening, according to various uses and purposes. However, it has been proposed to use pumice as a culture medium because it does not require a large amount of nutrient solution, does not cause the nutrient solution to stay, and does not easily cause disease. However, even if pumice is used as a culture medium, no research has been conducted on the properties of pumice that is suitable as a culture medium for facility cultivation, or what particle size is suitable. The present invention finds optimal physical properties and particle size when pumice is used as a culture medium, particularly in a cultivation method using a solid medium for rooftop greening, requires little labor for cultivation, easily manages water, basically It is an object of the present invention to provide a rooftop and aboveground greening medium that does not generate drainage.

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies on the effects of various physical properties of pumice on the rooftop and above-ground greening media. Among various media, the use of granular volcanic pumice as a medium has an advantage that the cultivation operation is simplified because the medium has good water permeability, is lightweight, and has no tackiness. In addition, this granular pumice culture medium has less nutrient replenishment function to the rhizosphere and lower retention function of fertilizer components than soil, but the nutrient solution is appropriately supplied by a dropping tube, so that the isolated bed including crops can be obtained. There is an advantage that an appropriate water state can be maintained with a droplet supply amount substantially equal to the evaporation amount of water from the water. Therefore, cultivation can be performed with a very small amount of water and a very small amount of energy.

[0008] Pumice is a volcanic eruption, when felsic magma such as rhyolite and andesite is erupted into the air, a sudden drop in pressure releases volatiles in the magma, causing many pores to form. The resulting vitreous rock is characterized by having a myriad of small holes that look like porosity bubbles. Pumice is usually distinguished by its locality. The reason for this is that the physical properties of the rocks, which are the raw materials of pumice, differ depending on the type of the rock. When the pumice is composed mainly of andesite, it is slightly black, whereas when it is composed mainly of rhyolite, it shows white or light gray, and the latter is more porous.

The present inventors have conducted research on various characteristics of pumice as a medium used in a solid medium system for rooftop and above-ground greening. As a result, the inventors focused on saturated hydraulic conductivity and air permeability, and found that saturated hydraulic conductivity was 0.1%. 1 to 1.0 cm / sec,
Air permeability coefficient is 5-60cm / sec for dry and wet materials
c, from the viewpoint of lightness for rooftop greening, it was found that by using granular pumice having a bulk specific gravity of 0.3 to 0.8, a very excellent culture medium for cultivation could be provided. The invention has been completed. The cultivation medium composed of granular pumice having physical properties within such a range, embodies ideal environmental conditions for water absorption and respiration of the roots of the crop,
Furthermore, aerobic conditions are maintained in the medium, which suppresses the growth of anaerobic bacteria and exerts the effect of suppressing the onset of root diseases.

That is, the present invention has the following constitution. (1) As a medium for rooftop and above-ground greening, a rooftop and above-ground greening characterized by being composed of granular pumice having a bulk specific gravity smaller than that of ordinary soil and a bulk specific gravity of pumice being 0.3 to 0.8. Medium. (2) The granular pumice has a saturated hydraulic conductivity of 0.1 to 1.
0 cm / sec, air permeability coefficient is 5 for dry and wet samples
(1) characterized in that it is 60 cm / sec.
The medium for rooftop and above-ground greening described in 1. (3) The (1), wherein the granular pumice has a cation exchange capacity of 1 to 10 meq / 100 g.
Or the rooftop and above-ground greening medium according to (2). (4) The granular pumice stone has a particle diameter of 0.1 to 10 mm, any one of the above (1) to (3).
The medium for rooftop and above-ground greening described in the item. (5) The granular pumice stone is subjected to a drying step after mining so as to have a water content of 5.0% or less, and is thus adjusted to any one of the above (1) to (4). The medium for rooftop and above-ground greening described in the item. (6) The above (1) to characterized in that charcoal is further blended.
The medium for rooftop and above-ground greening according to any one of (5).

[0011]

DETAILED DESCRIPTION OF THE INVENTION As described above, the cultivation medium according to the present invention is characterized by being composed of granular pumice having a light weight and a saturated water permeability and a permeability within a predetermined range. The pumice used in the culture medium according to the present invention preferably has a saturated hydraulic conductivity in the range of 0.1 to 1.0 cm / sec. The saturated hydraulic conductivity is 0.1cm
If it is less than / sec, the diffusion of water is too slow, the water content of the culture medium becomes uneven, and the old culture solution tends to stay and damage the roots of the plant, which is not preferable. On the other hand, if it exceeds 1.0 cm / sec, the diffusion of water is too fast, and the water escapes from the medium, making it difficult to supply sufficient water or supplement nutrients, which is not preferable. The “saturated hydraulic conductivity” is described, for example, in “Soil Environment Analysis Method”, supervised by the Japan Society of Soil Fertilizer, edited by the Soil Environment Analysis Method Editing Committee, published by Hirotomo Publishing Co., Ltd., 1997, first printing, pp. 66-69. ing. The saturated hydraulic conductivity defined in the present invention is determined by a constant water level method. FIG. 1 is a conceptual diagram showing an example of a soil permeability meter (for example, DIK-4000, manufactured by Daiki Rika Kogyo Co., Ltd.) used for measuring the saturated permeability coefficient by the constant water level method.

First, a sampling cylinder 1 filled with a sample to be analyzed
Is connected to a constant water level holder 3 by a rubber ring 2. Next, the sampling cylinder 1 is placed in the water tank 4 and positioned above the drainage pipe 6 of the constant water level holder 3. This is for draining surplus water. The lower portion of the sampling cylinder 1 is stopped by a wire mesh cap 11. The graduated cylinder 8 is placed below the drain port 7 of the water tank, and the free nozzle 9 is positioned above the constant water level holder 3 to start water supply from the water supply pipe 10. At this time, the soil surface is protected with a piece of filter paper so that the water surface does not disturb the soil surface of the sample. Use normal temperature water. The water supply amount is appropriately adjusted by the cock of the universal nozzle 9 so that the water level in the constant water level holder is kept constant, and the water supply amount is set in the measuring cylinder for a predetermined time t (s).
The volume Q (ml) of the water flowing during ec) is measured.
The measurement is repeated two or three times.

The saturated hydraulic conductivity (cm / sec) of the sample is
It is calculated as coefficient K by the following equation. K = Q {(AtH) / L} (1) In the above equation, Q is the flow rate (ml); A is the cross-sectional area of the sample (c
m ² ); t is time (sec); H is position difference (cm); L is sample thickness (cm).

The pumice used in the culture medium according to the present invention has an aeration coefficient of 5 to 6 for both dry and wet samples.
0 cm / sec, preferably 20 to 30 cm
/ Sec is more preferable. The ventilation coefficient is 5cm
If it is less than / sec, the supply of oxygen to the root will decrease, which may promote the growth of anaerobic bacteria aggressive to plants, which is not preferable. If it exceeds 60 cm / sec, there is no problem in terms of oxygen supply, but since the porosity is high, the root and the medium tend to be hard to adhere to each other, which is not preferable. The wet sample refers to a sample immediately after being left under water saturation for 24 hours.

The “air permeability coefficient” is, for example, “Soil physical property measurement method”, supervised by the Secretariat of the Agriculture, Forestry and Fisheries Technology Council of the Ministry of Agriculture and Forestry, edited by the Soil Physical Property Measurement Method Committee, published by Yokendo, published in 1978, 2nd volume 2
It is described on pages 70-273. FIG. 2 is a conceptual diagram of an apparatus for measuring the permeability coefficient of soil. For the actual measurement, for example, a soil permeability meter DIK-
5001 or the like is used. In FIG. 2, reference numeral 12 denotes a cylinder containing a sample, which is inserted into a thick rubber plate 13 in close contact therewith. The rubber plate 13 is placed on the glass container 14 while keeping the air tightness. The difference between the inlet pressure and the outlet pressure of the sample with the underwater manometer 16 (P2-P1) (head cm)
While measuring a constant amount (Qcm ³ ) of air with the gas meter 15 while measuring the air flow, the passage time t (s)
ec) is measured. Channel area is Acm ² , channel length is Lc
Assuming m, the air permeability coefficient Ka (cm / sec) is obtained by the following equation. Ka = Q × L / {(P2-P1) × A · t} (2)

Further, the pumice used in the culture medium according to the present invention more preferably has a cation exchange capacity of 1 to 10 meq / 100 g. In the present specification, meq / 100 g means milliequivalent per 100 g of dry soil. Cation exchange capacity is 1meq / 100g
If it is less than 10 g, the fertilizing power is small and the yield is poor, which is not preferable. Also, due to the composition of the pumice, the cation exchange capacity hardly exceeds 10 meq / 100 g. The measurement of the cation exchange capacity can be performed, for example, using the semi-micro Scholl described in the above-mentioned “Soil Environment Analysis Method”, pp. 208-210.
The method can be performed using the Enberger method (a method in which the Schollenberger method using 1 M ammonium acetate having a pH of 7.0 is reduced to 1/10). Sch
In ollenberger method, to create a soil column infiltration tube, after exchange and leaching exchangeable cations in NH ₄ ⁺ in ammonium acetate with ethanol to wash the excess ammonium acetate, followed by NH ₄ with sodium chloride solution ⁺ Is leached, NH ₄ ⁺ is quantified by steam distillation, titration, or the like, and the adsorbed NH ₄ ⁺ is used as the cation exchange capacity.

According to the study of the present inventors, pumice was 0.1%.
It has been found that, when the particle diameter is in the range of 10 to 10 mm, the saturated water permeability, the permeability coefficient, and the cation exchange capacity in the range defined above are often high. Above all,
It has been found that Shirasu pumice in the Kagoshima prefecture region having a particle size in the above-mentioned range has the appropriate saturated hydraulic conductivity, permeability coefficient and cation exchange capacity defined above. For example, pumice particles having a particle size of 0.1 mm or less have an air permeability coefficient of around 10 cm / sec for a dry sample and 2 to 5 cm / sec for a wet sample.
sec. Therefore, when pumice particles having a particle size of 0.1 mm or less are used, the air permeability becomes extremely poor particularly in a wet state. When the particle size is in the range of 0.1 to 10 mm, a dried sample,
An excellent permeability coefficient is obtained stably for both wet samples.

The particle size is divided using, for example, a standard test sieve described in JIS Z8801. Pumice having a particle size of 0.1 to 10 mm refers to a size that passes through a sieve having a nominal size of 10 mm according to JIS Z8801 and does not pass through a sieve having a nominal size of 0.1 mm. The sieving is operated in a conventional manner, and the particle size value refers to the particle size value of the main particles in effect. 1 in total weight
It does not matter that fine powder is contained in a proportion of 0% by volume or less, and such pumice is also included in the scope of the present invention. Therefore, the pumice used in the rooftop and ground revegetation medium according to the present invention has a particle size in the range of 0.1 to 10 mm, and a saturated hydraulic conductivity in the range of 0.1 to 1.0 cm / sec. It is particularly preferable that the air permeability coefficient is 5 to 60 cm / sec for both the dry sample and the wet sample. Furthermore, it is more preferable that the pumice used in the medium for rooftop and above-ground greening according to the present invention has a particle size in the above range and a cation exchange capacity of 1 to 10 meq / 100 g. Pumice with a particle size of less than 0.1 mm often has a cation exchange capacity of 1.0 meq /
Drops to less than 100 g.

The Shirasu pumice is described with its definition in, for example, “Environment of the Earth”, supervised by Shinno Iwata et al., Published by Fuji Techno System Co., Ltd., 1997, pp. 30-32. According to this, "Shirasu" is a general term for "non-welded parts of pyroclastic pumice flow deposits erupted from the large-scale Kakkadera volcano of the late Sara Pleistocene or its secondary deposits". The ones in South Kyushu are well known. In addition, similar shirasu are distributed around caldera volcanoes such as Lake Kussharo, Mt.Tokachi, Lake Shikotsu, Lake Toya, Lake Towada, Mt.Aso, etc. Here is illustrated as a pumice flow deposit. FIG. 3 shows a 500 × magnification micrograph of Shirasu pumice, and FIG. 4 shows a 500 × magnification micrograph of sand grains. 3 and 4, the porosity of Shirasu pumice is confirmed.

Further, as described above, the pumice used for the rooftop and ground revegetation medium according to the present invention is mined and sorted in the range of particle size of 0.1 to 10 mm, and immediately has a water content of 5.0. % Is more preferably subjected to a drying step. Therefore, another aspect of the present invention is to perform a drying process after mining granular pumice having a saturated hydraulic conductivity of 0.1 to 1.0 cm / sec and a permeability coefficient of 5 to 60 cn / sec for dry and wet samples. The present invention relates to a rooftop and above-ground greening medium composed of pumice stone adjusted to have a water content of 5.0% or less.

The mined pumice has organic substances and microorganisms attached to the voids and the like, or adheres during handling, and this has an adverse effect on cultivation, and the organic substances and microorganisms such as these are removed. The physical and chemical properties of pumice may be unstable due to the presence of pumice, but by performing a drying process on pumice immediately after mining, the physical and chemical properties of pumice are stabilized and the propagation of microorganisms Can be provided, and a cultivation medium capable of maintaining stable quality can be provided. Drying can be performed by a heating furnace, a microwave oven, or the like. When a heating furnace is used, it should be heated to at least 105 ° C. as the temperature of the pumice, and it is preferable to heat at about 250 ° C. In addition, when using a microwave oven, it is necessary to use an industrial-use microwave oven having a large output. The heating time is a time at which the moisture content of the pumice becomes 5.0% or less. Since the amount of water initially contained in pumice is often different, it is desirable to take a slightly longer heating time for safety. It is desirable that the pumice stone after the drying process is stored in a sealed bag such as vinyl when moisture reaches room temperature.

The moisture content of the soil is represented by the following equation. Moisture content (wt%) = (moisture weight / wet soil weight) × 100 (3) where, moisture content = wet soil weight−dry soil weight, and dry soil weight is
This is the weight after drying the collected soil at 105 ° C. for 24 hours. The definition of the dry soil weight is based on the description of the above-mentioned “Soil Environment Analysis Method”, pp. 21-23.

Further, the present inventors have further improved the rooftop and the more suitable for large-scale cultivation by further mixing granular charcoal with a cultivation medium composed of granular pumice having the above-mentioned predetermined physical properties. It has been found that a medium for above-ground greening can be provided. Such a mixed medium can increase the water holding power and fertilizing power under conditions in which the physical properties and chemical properties of the medium are almost the same as those of the pumice medium, and can grow the seedlings at a high growth rate after planting. Therefore, still another embodiment of the present invention relates to a medium for rooftop and above-ground greening, wherein charcoal is further added to the medium composed of the granular pumice as defined above.

The granular charcoal that can be used here may be any charcoal obtained by carbonizing various organic materials. However, from the viewpoint of water retention and fertilizer retention, the degree of porosity is large. Are preferred. Examples of the form of charcoal that can be preferably used in the preferred embodiment of the present invention include charcoal, bamboo charcoal, rice charcoal, and the like. In a preferred embodiment of the present invention, the purpose of adding charcoal is to compensate for the drawback of volcanic pumice, which has poor fertilizing ability, so that it has a high degree of porosity and high water retention and fertilizing power. preferable. Also, for example, the use of carbonized agricultural by-products, specifically, for example, the carbonized beer lees (waste) leads to effective use of waste, which is extremely preferable. Furthermore, it is preferable that the charcoal used in the culture medium according to a preferred embodiment of the present invention be circulated and reused from the viewpoint of its effective use.

The particle size of the charcoal may be substantially the same as the particle size of the pumice stone, but can be appropriately selected depending on the porous state of the charcoal, the mixing ratio with respect to the pumice stone, and the like. The preferred particle size of the charcoal is preferably in the range of 1 to 5.6 mm, and the average particle size is selected depending on the situation. Charcoal having an average particle size such that it mixes uniformly when mixed with pumice is preferred. The mixing ratio of pumice and charcoal can be variously selected depending on the crop to be cultivated.
The range can be 1 to 0.5 times.

[0026]

The following examples further illustrate various aspects of the present invention. These examples show specific examples of the present invention, and the present invention is not limited to these examples.

Example 1 FIG. 5 shows the concept of a cultivation apparatus for rooftop and ground greening used in this example. A cultivation box 20 having a size of 450 mm × 1200 mm was provided, filled with Shirasu pumice 21 calculated by Kagoshima to a depth of 80 mm, and Saladana A was cultivated in July and August. The cultivation test was performed in Shizuoka Prefecture. The used Shirasu pumice 21 was screened at a particle size of 1.0 mm to 5.6 mm using a 5660 μm sieve and a 1000 μm sieve, and dried at 250 ° C. for 4 hours in a heating furnace. The moisture content of the pumice was 0.2%. The saturated hydraulic conductivity of pumice is 3.4 ×
10 ^-1 cm / sec, air permeability coefficient is 29 cm /
sec, the wet sample was 27 cm / sec, and the cation exchange capacity was 3.4 meq / 100 g. A perforated water discharge pipe 23 in which water discharge holes 22 are scattered in a line in a length direction on a peripheral wall at predetermined intervals was horizontally laid over the cultivation box 20, and watering was appropriately performed. Germination was confirmed 2 days after sowing the saladana, and 10 days later, it was planted in the cultivation box 20 in the greenhouse. The cultivation area was 20 m ² . Nutrients (liquid fertilizer) and water were replenished by pouring under sunlight. Planting 30
After the day, there was a harvest of 1m ² per 36 shares. Twelve of the harvested salads were weighed. Here, the weight of the plant is the weight of the saladner excluding the root. The results are shown in Table 1.

[0028]

[Table 1]

Comparative Example 1 A cultivation test of salad na was conducted in the same manner as in Example 1 except that sand having the following properties was used as a medium instead of shirasu pumice. The particle size of the sand used was 0.2 to 1.0 mm, the water content was 0.5 wt%, the saturated hydraulic conductivity was 3.7 cm / sec, the ventilation coefficient was 59 cm / sec for the dry sample, and 63 for the wet sample.
cm / sec, cation exchange capacity is 0.9 meq / 10
It was 0 g. The cultivation area was 10 m ² . There is a harvest of 1m ² per 22 shares, and weighed about 12 of which strain. The results are shown in Table 2. The average strain weight of the 12 strains was 82.9 g. By comparing Example 1 with Comparative Example 1, it is possible to increase the planting density and to increase the weight per plant by using the pumice medium according to the present invention as compared with sand culture. I understand.

[0030]

[Table 2]

Comparative Example 2 Shirasu pumice from Kagoshima Prefecture was sieved to a particle size of less than 0.1 mm.
Saturated hydraulic conductivity, permeability coefficient, cation exchange of selected samples
The capacity was measured. The saturated hydraulic conductivity is 2.5 × 10 ^-2cm /
sec and about 10 minutes of the Shirasu pumice sample used in Example 1.
1 or less. The air permeability coefficient is 12 cm / sec for dry samples
c, 4 cm / sec for the wet sample, especially for the wet sample
The ventilation coefficient was low. The cation exchange capacity is 1.3.
meq / 100 g.

Example 2 A cultivation test was performed using a medium in which pumice was mixed with charcoal.
As the pumice, the same Shirasu pumice sample used in Example 1 was used. Pulverize charcoal (coconut charcoal) to a particle size of 1
Charcoal particles adjusted to 2 mm are prepared, and charcoal is 0% (A) and 10% by weight with respect to Shirasu pumice stone, respectively.
(B), 20% (C), 30% (D), 40% (E),
A mixed medium was formed to be 50% (F). Saladana was grown in each medium. Cultivation was performed in Okinawa Prefecture. Sown at the end of May, planted 17 days after sowing, and harvested 32 days later. The irrigation method was a trickle-drip flow, and irrigation was performed at an amount of 50 ml / strain during seedling raising and at an amount of 60 ml / strain during planting. Liquid fertilizer was applied as fertilizer. Twenty-one strains were harvested for each medium, and the average weight of the salad per strain (weight excluding the root) was determined. The results are shown in Table 3 and FIG.

[0033]

[Table 3]

From Table 3 and FIG. 6, it can be seen that the weight of the salad cultivated on the medium containing the charcoal increased by an average of 20 g per strain, compared to the salad cultivated on the medium containing no charcoal.

Example 3 A continuous cultivation test was conducted using a medium in which pumice was mixed with charcoal. As the pumice, the same Shirasu pumice sample used in Example 1 was used. The charcoal (yashigara charcoal) is pulverized and classified in the same size as in the Shirasu pumice test (particle size: 1 to 5.6).
mm), charcoal particles having adjusted particle size are prepared, and the charcoal is 0% (A) and 10% by weight, respectively, with respect to Shirasu pumice.
% (B), 20% (C), 30% (D), 50%
(E), 80% (F), and 100% (G) were mixed to form a culture medium. Each mixed medium was collected so as to have a weight of 800 g per pot, and housed in a 1-liter Pyrex (registered trademark) beaker as a medium, and Komatsuna was cultivated in each medium.

Cultivation was performed in Shizuoka Prefecture. About 1 after sowing
The plants were planted on day 0 and harvested about 30 days later. This one
We performed 0 consecutive crops. As a nutrient solution, a solution obtained by adding nutrients based on river water was used. The ratio of added nutrients is as follows: culture solution of horticultural test center standard formulation (ingredient concentration: N = 16 (meq / liter: hereinafter the same unit); P = 4; K = 8; Ca = 8; M
g = 4). The same amount of nutrient solution prepared in one nutrient solution tank was supplied to all the culture media at the same timing. During the cultivation test period,
The medium was housed in a greenhouse. The weight of the harvested Komatsuna strain was measured. The results are shown in Table 4. In addition,
The strain weight is the average of the values obtained by measuring the weight of 10 strains.
From Table 4, it can be seen that 10% more than Shirasu pumice 100% medium.
It can be seen that the harvest of the mixed medium containing 50% by weight of charcoal was increased, and that the crop yield did not decrease due to continuous cropping.

[0037]

[Table 4]

[0038]

The medium for rooftop and above-ground revegetation according to the present invention has a temporary specific gravity of, for example, 1.0 to 1.3 compared to that of general soil (sandy soil or viscous soil). Range 1
It is characterized by being composed of granular pumice having a bulk specific gravity of 0.45 to 0.6 and a numerical value of half or less of general soil, which is a granular pumice of 10 to 10 mm. Therefore, the load on the roof and on the ground is halved compared to the load on general soil,
It is a medium that is particularly suitable for rooftop greening because it does not cause a problem in strength for the building and easily meets the Building Standards Law. Plants that can be cultivated using the cultivation medium according to the present invention include, for example, vegetables, fruit trees, flowering plants, and trees.
Further, in a further preferred embodiment of the present invention, by adding charcoal to the medium, the water holding power and fertilizing power of the medium are increased, and it is possible to prevent a decrease in crop yield due to continuous cropping. Farming work is simplified. Further, the frequency of replacing the culture medium due to contamination of the culture medium is reduced, so that the economic burden due to the disposal of the used culture medium is reduced.

The granular pumice medium of the present invention requires a small supply of water and culture solution required for plant cultivation, so that the watering device required for cultivation on the rooftop and above the ground of a building is simplified, The rooftop and the ground portion of the building due to the supply of the medium and the culture solution are less damaged, and the life of the building is not shortened. The granular pumice medium of the present invention originally has a small cation exchange capacity (CEC) as compared with general soil. In the case of rooftop greening or greenery on the ground, since the medium is not covered, a large amount of water flows directly into the medium when it rains, causing the fertilizer components of the medium to flow out. Since the granular pumice medium has a CEC of about 3 meq / 100 g, CEC 15
It is about 1/10 of の 30 meq / 100 g, and no matter how much rain falls, the outflow of fertilizer components is small. Outflow is CE
If it is proportional to C, it is about 1/10, and the effect of preventing runoff of fertilizer is extremely large.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a soil water permeability measuring device used for measuring a saturated water permeability by a constant water level method defined in the present invention.

FIG. 2 is a conceptual diagram of a gas permeability measuring device used for measuring a gas permeability coefficient defined in the present invention.

FIG. 3 is a 500 × magnification micrograph of Shirasu pumice.

FIG. 4 is a 500 × magnification micrograph of a sand grain.

FIG. 5 is a diagram showing the concept of a cultivation test device used in Example 1 of the present invention.

FIG. 6 is a graph showing cultivation test results of Example 2 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soil collecting cylinder 2 Rubber ring 3 Constant water level holder 4 Water tank 5 Drain port 6 Drain pipe 7 Drain port 8 Measuring cylinder 9 Free nozzle 10 Water supply pipe 11 Wire mesh cap 12 Cylinder 13 Thick rubber plate 14 Glass container 15 Gas meter 16 Underwater manometer 20 Cultivation Box 21 Shirasu pumice stone 22 Water discharge hole 23 Perforated water discharge pipe A Salad vegetable

Claims (6)

[Claims] 1. A medium for rooftop and above-ground revegetation having a bulk specific gravity smaller than that of ordinary soil, and a pumice having a bulk specific gravity of 0.3 to 0.1.
8. A medium for rooftop and above-ground greening, comprising a granular pumice of No. 8. 2. The granular pumice has a saturated hydraulic conductivity of 0.1.
The rooftop and above-ground greening medium according to claim 1, wherein the culture medium has a permeability of 5 to 60 cm / sec for a dry sample and a wet sample. 3. The method according to claim 1, wherein the granular pumice is 1 to 10 meq / 10.
The rooftop and above-ground greening medium according to claim 1 or 2, having a cation exchange capacity of 0 g. 4. The medium according to claim 1, wherein the granular pumice has a particle size range of 0.1 to 10 mm. 5. The granulated pumice stone is subjected to a drying step after mining so as to have a water content of 5.0% or less. The medium for rooftop and above-ground greening described in 1. 6. The rooftop and above-ground greening medium according to claim 1, further comprising charcoal.