JPH01287193A - Agricultural and horticultural soil and production thereof - Google Patents

Abstract

PURPOSE:To provide the title inexpensive soil, easy to produce, also suitable for mass production, by comprising a specific granular zeolite, a water- absorptive polymer, and PVA in specified proportion. CONSTITUTION:The objective soil comprising (A) 100pts.wt. granular zeolite having fine open cells (pref. ca. 200-300mum in size, ca. 50-150m<2>/g in specific surface area, and 20-40ml/g in fine cell volume), (B) 1-20pts.wt. of a water- absorptive polymer pref. consisting of polyacrylic alkali salt crosslinked form- based one, and (C) 1-15pts.wt. of PVA pref. >=(esp. ca. 80-98) in saponification degree, and 1,000-2,000 (esp. ca. 1,500-1,800) in polymerization degree.

Description

[Detailed description of the invention] Industrial applications The present invention relates to agricultural and horticultural soil and a method for producing the same.

Conventional technology and its problems In order for plants to grow well, soil needs to have appropriate water retention and air permeability.Furthermore, for many plants, soil elasticity also affects growth. has become an essential condition.

In recent years, efforts have been made to prevent deterioration of soil properties due to the large use of chemical fertilizers,
In order to cope with the increasing greening movement in response to the loss of vegetation due to overdevelopment and urbanization, there is an urgent need for a soil conditioner with higher performance than ever before.

Traditionally, rice straw, wheat straw, rice husk, dried grass, etc. have been used to improve soil water retention, air permeability, elasticity, etc., but these days it is becoming extremely difficult to obtain these. For this reason, natural materials such as Kanuma soil, perlite, humus, peat moss, and park compost are often used as soil conditioners, and recently synthetic materials such as water-absorbing polymers and composites containing them are also being used. , is beginning to be used.

However, these soil improvement materials made of natural and synthetic materials can only improve some of the soil properties necessary for plant growth, and their application range is limited to potted plants and seedlings. There is. Moreover, it is difficult for these soil improvement materials to mix uniformly with the soil, and even if they are effective at the time of planting, they lose their effectiveness over time.

Means for Solving the Problems The inventor of the present invention has conducted extensive research in view of the problems of the prior art as described above, and as a result has succeeded in completing the foundation of a new configuration.

That is, the present invention provides the following agricultural and horticultural soil and its manufacturing method.

■Powdered or small-sized zeolite 10 with fine interconnected pores
0 parts by weight, 1 to 20 parts by weight of a water-absorbing polymeric substance, and 1 to 10 parts by weight of polyvinyl alcohol (hereinafter referred to as the first soil of the present invention); Powdered to small lump zeolite 30
-80% by weight and 70-20% by weight of a powdery or small lump inorganic substance, 1-20 parts by weight of a water-absorbing polymeric substance, and 1-15 parts by weight of polyvinyl alcohol. Soil (hereinafter referred to as the second soil of the present invention): ■ After kneading a water-absorbing polymeric substance and an aqueous solution of polyvinyl alcohol and gelling it, powdery or small-sized zeolite or finely connected zeolites having finely connected holes are added to the mixture. A method for producing soil for agricultural and horticultural purposes (hereinafter referred to as the method of the present invention) characterized by adding a mixture of a powdery or small-sized zeolite having pores and a powdery or small-sized inorganic substance, kneading, shaping, and drying the mixture. do).

In the present invention, agricultural and horticultural soil includes not only soil used for agriculture and horticulture, but also soil used for purposes such as afforestation and greening.

Moreover, the agricultural and horticultural soil according to the present invention can not only be used as a soil for growing, but also exhibits the effect as a soil improving material for the soil for growing. However, in the present specification, this will simply be referred to as agricultural and horticultural soil.

The first soil of the present invention and the second soil of the present invention will be described in detail below.

■1 First soil of the present invention The zeolite used in the present invention provides soil with air permeability, water absorption and water repellency, mainly due to its fine continuous pores.
It exhibits effects such as heat retention. Therefore, particle size 2
About 0 to 300 μm, specific surface area 5O-15c) rTI/
It is preferable to use one with a pore volume of about 20 to 40 cc/g. Zeolite facilitates uniform mixing with the soil to be improved when the product of the present invention is used as a soil improvement material. The composition of the zeolite is not particularly limited as long as it satisfies the above conditions.

The water-absorbing polymer substance used in the present invention absorbs a large amount of water in the soil and becomes an elastic body, and not only gives elasticity to the soil, but also retains water or water and nutrients contained therein for a long time. It exhibits a "sustained release effect" in which it is released little by little over a period of time. Examples of such water-absorbing polymer substances include alkali polyacrylate cross-linked systems, vinyl alcohol acrylate systems, modified polyethylene oxide systems, starch and
Although known ones such as acrylic acid graft copolymer systems can be used, it is more preferable to use polyacrylic acid alkali salt crosslinked systems from the viewpoint of water absorption capacity, shape retention, etc. Even when the polyacrylic acid alkali salt cross-linked system is eluted into soil, it exhibits neutrality and therefore does not have any adverse effects on plants. Its particle size is 10~300μ
It is preferable to set it to about m. The amount of the water-absorbing polymer material to be added to 100 parts by weight of zeolite (hereinafter simply referred to as "parts") may vary depending on the field of use as soil, but is usually within the range of 1 to 20 parts. If the amount of the water-absorbing polymer substance is less than 1 part, the amount of water absorbed is small (,
The effect of improving soil elasticity will also be insufficient. On the other hand, if the amount of the water-absorbing polymer substance exceeds 20 parts, the amount must be reduced when using the product of the present invention as a soil conditioner, making it difficult to mix uniformly into the soil. becomes.

It also increases the possibility of collapse in the soil.

In the present invention, polyvinyl alcohol (hereinafter referred to as PV
Blend A). As PVA, saponification degree is 70
or more (more preferably about 80 to 98), degree of polymerization 100
About 0 to 2000 (more preferably 1500 to 1800)
degree) is usually used. The degree of saponification of PVA is 7
If it is less than 0, the shape retention in contact with the soil to be improved will be reduced and the elasticity will also be insufficient. Also, PV
If the degree of polymerization of A is less than 1,000, the water resistance will be insufficient and the shape will easily collapse;
If it exceeds 0, the viscosity is too high and molding becomes difficult. The amount of PVA to be added to 100 parts of zeolite in the first soil of the present invention may vary depending on the field of use of the soil, but it is usually within the range of 1 to 10 parts.

If this amount is less than 1 part, the shape retention and agglomeration effects described above will be insufficient, and if it exceeds 10 parts,
It becomes difficult to mold during the manufacturing process, and the thick film blocks the pores of the zeolite, reducing its water absorption capacity.

■1 Second soil of the present invention The second soil of the present invention consists of 100 parts of a mixture of 30 to 80% powdery or small lumpy zeolite having fine interconnected pores and 70 to 20% of powdery or small lumpy inorganic material, and has high water absorption. molecular substance 1
~20 parts and 1-15 parts of PVA.

The zeolite, water-absorbing polymer material, and PVA used in the second soil of the present invention are the same as those used in the first soil of the present invention.

In the second soil of the present invention, a powdery or small-sized inorganic substance is used in a mixed state with zeolite. Examples of such inorganic substances include pumice, pearlite, whitebait, Kanuma soil, clay, silica sand, vermiculite, and humus, but among these, pearlite-based substances are more preferred. The proportion of powdery or nodular inorganic material in the mixture with zeolite is
It should be about 20-70%. The proportion of inorganic substances is 20%
If it is less than, the effect is different from that of zeolite alone.
8 - It does not change much, but if it exceeds 70%, the effect of using zeolite will hardly be exhibited.

The particle size of the inorganic substance is preferably about 40 μm to 1 mm.

The reason why the upper limit of PVA content in the second soil of the present invention is set to 15 parts is that the inorganic substance has poor shape retention compared to zeolite.

Note that various auxiliary materials can be added to the soil of the present invention, if necessary.

For example, in order to improve shape retention strength by forming the soil of the present invention into a rod shape, a pile shape, a pipe shape, etc., and to make it easier to store, transport, insert and drive into the soil to be improved, inorganic materials can be used as reinforcement. Alternatively, an organic fibrous material such as rock wool (mineral fiber), pulp, peat moss, etc. can be used in combination.

Furthermore, by incorporating organic and inorganic fertilizers, active soil bacteria, neutralizing agents such as calcium carbonate, etc., the effect as a soil conditioner can be further enhanced.

The agricultural and horticultural soil of the present invention is usually produced as follows.

First, a PVA aqueous solution prepared by dissolving it under heating and a water-absorbing polymer substance are kneaded and gelled.

Next, zeolite or a mixture of zeolite and an inorganic substance is added to this, kneaded, shaped, and dried to obtain desired agricultural and horticultural soil.

Molding is usually carried out by a compression method, preferably by an extrusion method. The morphology of the soil is generally 1 to 1.
It is preferable to form particles of about 0 mm. However, if necessary, it can be made into any shape such as a rod, a pile, a block, or a pipe. In this case, the above-mentioned inorganic or organic fibrous material as a reinforcing material may be added to the zeolite or a mixture of zeolite and an inorganic material, and this and the gelled material may be kneaded.

Effects of the Invention The agricultural and horticultural soil according to the present invention is inexpensive, easy to manufacture, and suitable for mass production.

Furthermore, when the agricultural and horticultural soil of the present invention itself is used as growing soil or as a soil improvement material for growing soil, the following effects are achieved.

(b) As schematically shown in Figure 1 (a) and (b),
When the surrounding soil has excessive moisture (indicated by ×), the granular agricultural and horticultural soil of the present invention absorbs water rapidly (indicated by ◎), and when the surrounding soil is dry, it absorbs water rapidly. Since the retained water is released into the soil, soil moisture can be retained at an amount suitable for root growth over a long period of time.

Therefore, the number of irrigations can be reduced to about 1/2 to 1/3 compared to conventional methods, and appropriate soil conditions can be maintained, resulting in stable growth of above-ground and underground parts of plants. is encouraged.

(b) As schematically shown in Figure 2, the granular agricultural and horticultural soil according to the present invention changes from its initial state (a) to a swollen state (b) due to water absorption, and then to a contracted state (C) due to water generation. ,
In some cases, a contracted state (c) forming voids (1)
Then it returns to the swollen state (b) due to water absorption. Therefore, when using the granular agricultural and horticultural soil according to the present invention, in addition to the water retention capacity due to the water-absorbing polymeric substance and the aeration capacity due to the zeolite, the water retention capacity and aeration capacity due to the voids (1) are also expressed. Harmful effects such as withering of plants and root rot are also prevented.

(c) The agricultural and horticultural soil of the present invention becomes highly elastic when the water-absorbing polymeric substance absorbs water, so it imparts elasticity to the entire soil and promotes the growth of plant roots.

(d) The agricultural and horticultural soil of the present invention has a large fertilizer retention capacity due to the high water retention properties of zeolite and water-absorbing polymeric substances, so it prevents fertilizer from being washed away and exhibits the effect of sustaining the fertilizer effect. do.

(e) In the granular agricultural and horticultural soil according to the present invention, in addition to the heat-insulating effect of the zeolite itself, a heat-retaining effect is obtained due to the formation of voids in the soil, so temperature changes in the entire soil can be moderated. .

(f) The granular agricultural and horticultural soil according to the present invention can be adjusted to an appropriate weight and particle size, so it can be easily mixed uniformly into the soil.

Furthermore, when the agricultural and horticultural soil according to the present invention is shaped into a rod, pile, pipe, etc., local soil improvement can be carried out by inserting or driving it into a predetermined ground with a simple operation. I can do it. More specifically, for example, the agricultural and horticultural soil of the present invention shaped into a rod may be inserted around plants that are already being cultivated, or the agricultural and horticultural soil of the present invention may be driven into a slope. You can.

(g) Since the agricultural and horticultural soil of the present invention is heat sterilized during the manufacturing process, it does not contaminate the soil with harmful bacteria, but rather uses the adsorption ability of zeolite to adsorb harmful bacteria in the soil and plant it. It has the effect of protecting the roots of.

(h) Since water-insoluble PVA with a relatively large molecular weight is used, the agricultural and horticultural soil of the present invention has excellent shape retention;
It does not disintegrate during handling, generate dust, or disintegrate due to water absorption in the soil, and maintains its effectiveness over a long period of time.

EXAMPLES Below, examples of the production of soil according to the present invention and examples will be shown to further clarify the characteristics of the present invention.

Production Example 1 2 to 8 parts of a crosslinked sodium polyacrylate having a water absorption capacity of about 500 to 1000 times its own weight (for example, trademark "Sumikagel N100SH", manufactured by Sumitomo Chemical Co., Ltd.), a polymerization degree of about 1500 to 2000, A 3-10% aqueous solution of PVA (trademark "Gohsenol NH18", manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) with a chemical degree of 98 mol% or more 60-10%
Add 100 parts of zeolite l-1 with a particle size of about 10 to 80 μm to the gelled product consisting of 0 parts and knead uniformly,
It is molded into a size of about m and dried.

The thus obtained granular agricultural and horticultural soil of the present invention has a large water retention capacity, appropriate air permeability, and good shape retention, so it is excellent as soil for potting plants and as a soil improvement material for green areas. It has a great effect.

Production Example 2 A cross-linked sodium polyacrylate having a deer water absorption capacity of about 500 times its own weight (for example, the trademark "Sumikagel N100S")
HT", manufactured by Sumitomo Chemical Industries, Ltd.) 2 to 6 parts and degree of polymerization 1
P of about 000 to 2000 and saponification degree of 85 to 90 mol%
100 parts of zeolide with a particle size of about 10 to 80 μm was added to a gelled product consisting of 60 to 80 parts of a 2 to 6% aqueous solution of VA (trademark “Gosenoil GH17”, manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.), and the mixture was uniformly kneaded. Then, it is molded to a constant particle size within a range of about 3 to 8 mm, and dried.

The thus obtained granular agricultural and horticultural soil of the present invention has appropriate water retention and air permeability, but its shape retention is slightly low. Therefore, it has an excellent effect as a soil improvement material for fields, paddy fields, etc. that may be destroyed during cultivation.

Production Example 3 Cross-linked sodium polyacrylate having a water absorption capacity of about 1000 times its own weight (for example, Pasmikagel N100 trademark)
", manufactured by Sumitomo Chemical Co., Ltd.) 1 to 5 parts and a degree of polymerization of about 20
00, and 40 to 60 parts of a 3 to 6% aqueous solution of PVA (trademark "GOHSENOL NH2O", manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) with a saponification degree of 98 mol% or more, and a particle size of about 10 to 80 μm. 40 to 60 parts of zeolide and 60 to 60 parts of pearlite pumice with a particle size of about 150 μm to 11
100 parts of the mixture consisting of 40 parts of the powder are added, kneaded uniformly, formed into a constant particle size within a range of about 3 to 8 mm, and dried.

The thus obtained granular agricultural and horticultural soil of the present invention has appropriate water retention, high air permeability, and high shape retention, and is therefore suitable for use as soil for vegetation such as orchids, for example.

Example 1 Using 100 parts of zeolite similar to those used in Production Example 1, 2 parts of a sodium polyacrylate crosslinker, and 70 parts of a 5% PVA aqueous solution, soil ① according to the present invention was obtained.

In addition, 100 parts of zeolite similar to that used in Example 1, 4 parts of sodium polyacrylate crosslinked product, and 5 parts of PVA
Soil ① according to the invention was obtained using 85 parts of % aqueous solution.

On the other hand, natural soil (2) having a maximum water holding capacity of 45% of its own weight was prepared.

Next, samples were prepared by uniformly mixing each of the above soils in the proportions shown below, and the water retention properties of each dried sample were examined.

Sample I: A mixture of 095 parts of natural soil and 05 parts of the soil of the present invention.

Sample ■: A mixture of 090 parts of natural soil and 010 parts of the soil of the present invention.

Sample ■: A mixture of 095 parts of natural soil and 05 parts of the soil of the present invention.

Sample ■: A mixture of 090 parts of natural soil and 010 parts of the soil of the present invention.

Sample V: 0,100 parts of natural soil.

The water retention test was conducted as follows.

First, a sample was dropped and filled up to the top of a plastic pot with a filter paper placed on the bottom, and then water was sprayed from above three times until water leaked from the bottom of the pot.

Next, each weight was kept at constant temperature and humidity (temperature 20°C, humidity 70%).
The total weight, including the pot, was measured every 24 hours to calculate the water content in the soil. The results are shown in Figure 3. In FIG. 3, the numbers I to ■ of each curve correspond to the above-mentioned sample numbers ■ to ■, respectively.

In addition, spherical filter paper was embedded 5 cm from the soil surface of each weight and removed every 24 hours to measure its moisture content and examine changes in soil moisture. The results are shown in Figure 4. In FIG. 4, the numbers ■, ■, and ■ of each curve correspond to the above-mentioned sample numbers I, ■, and V, respectively.

From the results shown in FIG. 3, it is clear that the soil according to the present invention has excellent water retention.

Moreover, from the results shown in FIG. 4, the soil according to the present invention is
It is clear that adequate moisture can be provided to the surrounding soil over a long period of time.゛

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the water absorption and water production of granular agricultural and horticultural soil according to the present invention. FIG. 2 is a diagram schematically showing the formation of voids due to water absorption and water generation in the granular agricultural and horticultural soil according to the present invention. FIG. 3 is a graph showing the excellent water retention properties of the soil according to the present invention. FIG. 4 is a graph showing the excellent water repellency of the soil according to the present invention. (Above) Jukan 11C knowledge game reward (X) ×◎×◎× Kutastexxxxxxxx xXXXXXX

Claims (1)

[Scope of Claims] [1] An agricultural product characterized by comprising 100 parts by weight of powdery or small-sized zeolite having micro-interconnected pores, 1 to 20 parts by weight of a water-absorbing polymeric substance, and 1 to 10 parts by weight of polyvinyl alcohol. Horticultural soil. [2] 30 to 80% powdery to small lumpy zeolite with fine interconnected pores and 70 to 20% powdery to small lumpy inorganic material
1. A soil for agricultural and horticultural use, comprising 100 parts by weight of a mixture of 1 to 20 parts by weight of a water-absorbing polymeric substance, and 1 to 15 parts by weight of polyvinyl alcohol. [3] After kneading a water-absorbing polymeric substance and an aqueous solution of polyvinyl alcohol to form a gel, add to this a powdery to small lumpy zeolite having fine continuous pores or a powdery to small lumpy zeolite having fine continuous holes. A method for producing soil for agricultural and horticultural use, which comprises adding a mixture with a powdery or small-sized inorganic substance, kneading, shaping, and drying.