JPH04267817A - Soil admixture - Google Patents

Abstract

PURPOSE:To provide a soil admixture, available at a low cost, readily processable, excellent in lightweight properties, air permeability and fertilizer carrying properties, having moderate water holding properties and water permeability and simultaneously containing plant rearing nutriments itself. CONSTITUTION:A soil admixture used in soil for rearing plants is foam glass grains composed of crushed wastes from a formed body of foam glass and the aforementioned foam glass grains have a soda lime-based glass composition, 0.8-1.5 apparent specific gravity and 0.5-5mm grain diameter. The above- mentioned glass composition contains 65-75wt.% SiO2, 10-15wt.% CaO and/or MgO and 10-15wt.% Na2O and/or K2O.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an admixture for soil suitable for growing plants.

0002

[Prior art and its problems] It is well known that the physical and chemical properties of the soil have an important influence on growing plants, and it is suitable for gardening, greenhouse cultivation, and seedling raising. It is customary to mix soil with appropriate admixtures to make up soil.

[0003] The preferred properties required for the admixture are as follows:
Appropriately low specific gravity, large porosity and air permeability, appropriate water retention and water permeability, ability to support fertilizers, easy absorption as nutrients by plants, and no harmful chemicals. etc. Examples of such mixed materials include pumice, (calcined) expanded shale, expanded pearlite, shirasu balloons, zeolite, metal smelting by-product slag, etc., which are already on the market or are being used on a trial basis. However, these mixed materials are depleting natural resources, require high costs for firing and foaming, or have a specific gravity that is too low or too high, or do not have adequate water retention or permeability. It is not always possible to satisfy the above requirements, such as when there is no fertilizer, there is no fertilizer-supporting property, the fertilizer itself is insufficient as a nutrient-supplying component, and sometimes contains harmful metals.

On the other hand, Japanese Patent Publication No. 2-51858 discloses the use of glass balloons as lightweight aggregates for structures, etc., as additives for fertilizers, soil conditioners, and other soil admixtures.

Glass balloons are made by firing and foaming a granulated mixture of glassy (amorphous) powder and a foaming material, or glassy powder and granules containing a foaming component, but manufacturing process such as raw material preparation and heat treatment is required. The use of other methods increases costs, and since the balloon surface has no noticeable open pores, it lacks water retention and fertilizer retention.

[0006] In view of these problems, the present invention has been completed as a result of intensive studies, and it makes effective use of waste resources.
It is easily available and can be processed at low cost, is lightweight, has excellent air permeability, has appropriate water retention and water permeability, has excellent fertilizer carrying capacity, and is suitable as fertilizer as it contains many components (nutrients) for plant growth. This provides a soil admixture that is suitable for use in soil.

[0007]

[Means for Solving the Problems] The present invention provides that the admixture to the soil for growing plants is foam glass granules made of crushed debris of foam glass moldings, and the foam glass granules have a soda-lime glass composition. The apparent specific gravity is 0.8 to 1.5, the particle size is 0.5 mm to 5 mm, and the glass composition is 65 to 75 wt% of SiO2, 10 to 15 wt% of CaO and/or MgO, Na2 O and/or
Alternatively, it contains 10 to 15 wt% of K2O.

[0008] Generally, foam glass particles (glass balloons) are formed by mixing raw material glass powder and an appropriate foaming material into particles, heat-treating the mixture, and foaming it. The waste generated during molding, processing, etc. of a foam glass molded product (usually called foam glass, but to distinguish it from the foam glass particles of the present invention) is used.

That is, the foam glass molded article is usually made by charging a mixture of soda-lime-based glass powder, foaming material, or appropriate heat-resistant inorganic powder, pigment, etc. into a molding frame, heat-treating it, and foaming it to increase the bubble diameter. Tens to several hundred μm, apparent specific gravity 0.3 to
1.8, and then cut and processed into a desired size and shape as necessary to produce a product.

[0010] At this time, waste of the foam glass molded product is generated, but in the present invention, the material with an appropriate specific gravity is selected and crushed to an appropriate particle size to obtain the raw material, that is, foam glass particles, and waste that should originally be discarded. This has the effect that kimono can be used effectively, and has the advantage that it can be easily pulverized during granulation.

[0011] The particle size of the foam glass particles is 0.5 mm to 5 m.
If the size is smaller than 0.5 mm, the air bubbles in the foam glass particles will be crushed, resulting in lightness, air permeability when mixed in soil, water permeability, water retention, fertilizer retention, etc. On the other hand, if the size exceeds 5 mm, it is likely to be crushed and abraded when mixed with soil, making it difficult to exhibit the above characteristics. The preferred range is 1 mm to 3 mm.

Foamed glass particles mainly have closed cells inside, but the surface is crushed and open pores are present, and some of them become open cells by crushing etc., which makes it easy to adsorb and support fertilizers, etc. By simply heating and foaming granular raw materials such as perlite and glass balloons, it develops unique properties compared to hollow glass without noticeable open pores.

The foam glass composition is a commonly used ordinary soda-lime glass composition, that is, 65 to 75 wt of SiO2.
%, 10 to 15 wt% of CaO and/or MgO,
10-15 wt% Na2O and/or K2O
Adopt those that fall within the scope of.

[0014] This composition range is not only suitable for melt molding of plate glass and container glass, but also extremely convenient for mixing the crushed product with a blowing agent and forming foam glass molded bodies and even foam glass granules by reheating. In addition, it is difficult to devitrify or crystallize even during the reheat treatment. i.e. glass (amorphous)
Because of this, it has the advantage that its constituent components, such as SiO2 and CaO, are easily absorbed as nutrients by plants compared to crystals such as quartz and feldspar, and it contains a large amount of crystals, such as known pumice and expanded shale. , SiO2-Al2O3
It is more suitable as an admixture than those with a system composition.

[0015] In addition to the above-mentioned SiO2 and CaO, Mg
O, K2O, etc. are provided as nutrients for plants. Alkaline components such as Na2O and K2O in glass,
Divalent components containing alkaline earth elements are gradually leached on contact with water and become alkaline, so they are particularly useful for neutralizing excessively acidic soil. Of course, it can be suitably used for plants that prefer alkali.

It is also said that if the apparent specific gravity of the foam glass particles is less than 0.8, they will float on water and phase separation from the mixed soil will easily occur, while if it exceeds 1.5, their lightness will be impaired and handling will be difficult. Therefore, it is set in the range of 0.8 to 1.5.

[0017]

[Examples] The present invention will be explained below based on Examples. [Example 1 and Comparative Example 1] Commercially available artificial soil mainly composed of peat moss was mixed with S
iO2 74.2wt%, CaO 8.3wt%, M
gO 2.2wt%, CaO+MgO 10.5w
t%, Na2O 12.3wt%, K2O2
．． 4wt%, Na2O+K2O 14.7wt%
, and some amounts of Al2O3, Fe2O3, T
10 vol% and 20 vol% of foam glass particles containing iO2, average particle diameter 1.4 mm, and average apparent specific gravity 0.85, respectively.
The mixture was added in portions, mixed well, and then filled into a pot with a capacity of 1 L. The mixed and prepared soil has a bulk specific gravity of less than 1.0, is easy to handle, and has a water retention capacity of 0.5 to 0.6 H2 Og.
/g, which is moderate. Three young Lisianthus seedlings that had been raised in advance were transplanted into each pot, and the survival rate of the seedlings was investigated 3 weeks after transplantation (Example 1).

For comparison, horticultural perlite with an average particle diameter of 1.5 mm and an average apparent specific gravity of 0.5 was mixed in the artificial soil in the same manner as described above, filled in a pot, and young Lisianthus seedlings were transplanted. We investigated the survival rate of seedlings after 3 weeks (
Comparative example 1). The results are also shown in Table 1.

[0019]

[Table 1]

[0020] In Example 1, the seedlings had excellent rooting and almost no plant defects were observed, but in Comparative Example 1, the perlite rose to the surface of the pot during irrigation and was separated from the artificial soil. The survival rate was slightly lower. For reference, a test using only artificial culture soil without any additives had poor affinity with water, and the seedlings took root in an uneven manner.

[Example 2 and Comparative Example 2] Red clay, rice clay,
Mulch, peat moss, vermiculite, and NPK
Foam glass granules made from crushed debris of foam glass molded bodies were mixed at 20 vol % into a seedling growing soil pre-prepared by mixing fertilizer, and the mixture was filled into a pot with a capacity of 0.5 L. The foam glass particles contain 65.9wt% of SiO2 and 10.7wt% of CaO.
%, MgO 3.4wt%, CaO+MgO 14
．． 1wt%, Na2O 8.5wt%, K2O
2.3wt%, Na2O+K2O 10.8w
t%, Al2O3 4.7wt%, BaO 2.6
wt%, SrO 1.2wt%, and some amount of Fe
It contains 2 O3, TiO2, and MnO2, and has an average particle size of 2.8 mm and an average apparent specific gravity of 1.43.

[0022] Young tomato seedlings that had been sown in advance were transplanted into the pots. After raising the seedlings for about a month and a half, they were planted in the field. Plant height, leaf weight, stem weight, and yield were investigated 70 days after planting (Example 2).

[0023] For comparison, using only the above-mentioned seedling raising soil without mixing foam glass particles, pots were filled in exactly the same manner as above, tomato seedlings were transplanted, and then planted in the field. Plant height, leaf weight, stem weight, and yield were investigated on the 70th day (Comparative Example 2). The results are also shown in Table 2.

[0024]

[Table 2]

As is clear from the table, in Example 2,
The roots of the seedlings had good root tension, and the seedlings grew firmly, and were superior to Comparative Example 2 in terms of plant height, leaf weight, stem weight, and yield.

[0026]

[Effects of the Invention] According to the present invention, the scraps of easily available foam glass molded bodies are effectively utilized, and the pulverization process is easy, and it is lightweight, has excellent air permeability, has adequate water retention, and has excellent air permeability. It is water-based, has excellent fertilizer-carrying properties, and can be supplied as a fertilizer in itself, so it is suitable as a material for cultivating soil for gardening, greenhouse cultivation, and seedling raising.

Claims (2)

[Claims] Claim 1: The admixture to the soil for growing plants is foam glass particles made of crushed debris of foam glass moldings, the foam glass particles have a soda lime glass composition, and have an apparent specific gravity of 0.
．． 8 to 1.5, and a particle size of 0.5 mm to 5 mm. [Claim 2] The glass composition is 65 to 75 wt% of SiO2.
, CaO and/or MgO 10-15 wt%,
Na2O and/or K2O 10-15wt
%, the soil admixture according to claim 1.