JP2007275022A - Method for promoting plant growth and plant growth promoter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy both global warming prevention and plant growth promotion. <P>SOLUTION: The method for plant growth promotion comprises spreading or plowing a carrier 1b attached with a methane oxidation bacterium 1a to or in soil 2 of plant-clustering lands and oxidatively decomposing methane in the soil 2 or released from the soil 2 into carbon dioxide by the methane oxidation bacterium 1a so as to make a carbon dioxide concentration in air at plant-clustering lands higher than that in the circumference. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plant growth promoting method and a plant growth promoting agent. More specifically, the present invention relates to a plant growth promotion method and a plant growth promoter suitable for use in promoting the growth of plants that carry out photosynthesis.

  As a method for increasing the yield per unit area of cultivated land, it is common to use chemical fertilizer. However, the use of chemical fertilizer increases the production cost, and the heavy use of chemical fertilizer may cause environmental pollution. Therefore, a method of utilizing what is normally present in nature is desired.

Thus, in recent years, in vegetable and fruit cultivation, attempts have been made to promote photosynthesis by increasing the carbon dioxide concentration in the greenhouse, thereby improving the yield and sugar content of vegetables and fruits (Patent Document 1). Here, between the atmospheric carbon dioxide (CO ₂ ) concentration of the plant group fabric and the photosynthesis rate of the plant leaves, as shown in FIG. 2, there is a relationship in which the photosynthesis rate increases as the atmospheric carbon dioxide concentration increases. It is known that there is (Non-Patent Document 1). Specifically, the yield of rice increased by 8 to 15% by raising the atmospheric carbon dioxide concentration from 350 ppm to 650 ppm in a closed-system artificial weather chamber experiment (Non-Patent Document 2). In addition, in an open-air atmospheric CO ₂ increase experiment, the result was that the yield of rice increased by up to 15% under a carbon dioxide concentration of about 200 ppm higher than the background atmosphere (Non-patent Document 3). In these experiments, in order to increase the carbon dioxide concentration in the atmosphere, for example, liquefied carbon dioxide stored in a tank or the like is vaporized and released into the atmosphere using a blower connected to a duct having a discharge port. I am doing so.

  In such a supply of carbon dioxide, the conventional method of promoting photosynthesis that increases the photosynthesis rate of plants by increasing the concentration of carbon dioxide in the atmosphere of the plant group dough, because the method of purging directly from the carbon dioxide cylinder to the atmosphere is inefficient The agent is, for example, a polymer composition having an initial carbon dioxide content of 2 to 70 parts by mass with respect to 100 parts by mass of the polymer, and continues to release carbon dioxide at 25 ° C. under atmospheric pressure. There has also been proposed a photosynthesis accelerator in which a molded article made of a carbon dioxide-releasing polymer composition for promoting photosynthesis is packaged in a breathable package, characterized in that the time is at least 100 hours (Patent Document) 1).

On the other hand, of the greenhouse gases that cause global warming, the annual total release of methane (CH ₄ ) is about 600 million tons, and it is released into the atmosphere from paddy fields and wetlands based on the natural generation of methane gas by decomposition of organic matter in the soil. It is said that about 40% of the total amount is released (Ryusuke Hatano: Monitoring of nitrous oxide and methane emission from farmland, biology science, genetics, separate volume, No.17 Global warming-from global trends To the countermeasure technology-裳 華 房, 2003). In addition, methane is more than 20 times the carbon dioxide in the global warming potential per molecule, and the contribution rate to the greenhouse effect is about 20%. It is said that a slight increase in concentration greatly affects global warming. . Therefore, according to the Kyoto Protocol adopted at the 3rd Conference of the Parties to the United Nations Framework Convention on Climate Change, the so-called COP3, the numerical target is to reduce the total emission of methane in terms of carbon dioxide by at least 5 wt% with the base year as 1990 And measures are required for major emission sources such as industry and agriculture and forestry.

Uchijima Yoshibei: New Global Warming and its Impacts, Hankabo, p. 127 Fig. 7 ・ 4, 2005 Morosumi, Yajima, Yonemura: Effects of elevated CO2 concentration and warming on the growth and yield of rice, Journal of the Crop Science Society of Japan 65 (2), pp.222-228, 1996 Kazuhiko Kobayashi: FACE (open air CO2 increase) experiment, Journal of the Crop Science Society of Japan 70 (1), pp.1-16, 2001 JP 2003-246880 A

  However, the photosynthesis promoter of Patent Document 1 is premised on use in a closed space such as a greenhouse, and is not considered for use in an open space. Furthermore, completely newly generated carbon dioxide is released into the atmosphere, which is against the prevention of global warming.

  In addition, methane, which has a global warming potential more than 20 times that of carbon dioxide and has a high ratio of emissions from plant populations such as paddy fields and wetlands to the total emission, is also suppressed from being released into the atmosphere. It is desirable.

  Therefore, an object of the present invention is to provide a plant growth promoting method and a plant growth promoting agent capable of achieving both prevention of global warming and promotion of plant growth.

  In order to achieve such an object, the present inventor has promoted the growth of plants and, in order to contribute to global warming prevention measures, suppresses the release of methane from the plant community to the atmosphere. From a natural viewpoint, the present invention has been completed based on a completely new idea that methane is converted to carbon dioxide and absorbed by plants to activate photosynthesis. In other words, the plant growth promoting method according to claim 1 is a method in which a carrier to which methane oxidizing bacteria are attached is sprayed or swallowed onto the soil of the plant group dough, and methane in the soil or methane released from the soil is oxidized and decomposed by the methane oxidizing bacteria. It is converted to carbon dioxide, and the carbon dioxide concentration in the atmosphere of the plant group dough is made higher than the surroundings.

  Therefore, according to this method for promoting the growth of plants, the carrier to which the methane oxidizing bacteria are attached is sprayed or put into the soil of the plant group dough, so that the methane in the soil or the methane released from the soil is oxidized by the methane oxidizing bacteria. It is decomposed and converted to carbon dioxide, and the concentration of carbon dioxide in the atmosphere of the plant group fabric increases.

  In the present invention, methane oxidizing bacteria are used to mean a group of bacteria having the ability to oxidatively decompose methane. Further, oxidative decomposition of methane means that methane is decomposed into carbon dioxide and water.

  In the plant growth promoting method according to claim 2, organic carbide is used as a carrier to which methane oxidizing bacteria are attached. In this case, the carrier is decomposed in the soil because it is an organic substance. Moreover, since it is a carbide | carbonized_material, a support | carrier becomes porous.

  Moreover, the plant growth promoter of Claim 3 is made to hold | maintain a methane oxidation microbe on a support | carrier.

  Therefore, according to this plant growth promoter, methane-oxidizing bacteria are retained on the carrier, so that, for example, by spreading or swallowing this carrier into the soil of the plant colony, methane in the soil or Methane released from the soil is oxidatively decomposed and converted to carbon dioxide, increasing the concentration of carbon dioxide in the atmosphere of the plant group fabric.

  The plant growth promoter according to claim 4 uses an organic carbide as a carrier to which methane oxidizing bacteria are attached. In this case, the carrier is decomposed in the soil because it is an organic substance. Moreover, since the support | carrier which is a carbide | carbonized_material is porous, it is an environment suitable for the habitation of methane oxidation bacteria, and the adhesion amount of methane oxidation bacteria increases.

  According to the plant growth promoting method and the plant growth promoting agent according to claims 1 and 3, methane in the soil or methane released from the soil is oxidatively decomposed and converted into carbon dioxide, and thus has a high global warming potential. Methane can be converted to carbon dioxide, which has a lower global warming potential, and this carbon dioxide can increase the concentration of carbon dioxide in the atmosphere of plant group fabrics, making the plant's photosynthesis active and promoting growth. . Furthermore, by oxidizing and decomposing methane into carbon dioxide, it is possible to suppress the release of methane, which has a higher greenhouse effect than carbon dioxide, into the atmosphere. In other words, by constructing a cycle in which methane is converted to carbon dioxide and the converted carbon dioxide is absorbed by the plant and oxygen is released, methane and carbon dioxide are actively used to reduce the amount released to the atmosphere. It is possible to simultaneously contribute to the prevention of global warming and promote the growth of plants.

  Furthermore, because methane oxidizing bacteria that inhabit the natural world are used, there is no risk of environmental pollution as in the case of using chemical fertilizers, and the growth of plants can be promoted without adversely affecting the natural environment. .

  According to the plant growth promotion method and the plant growth promoter of claims 2 and 4, since the carrier is decomposed in the soil, the growth of the plant can be promoted without adversely affecting the natural environment. Further, by using a porous carrier, it is possible to promote the growth of methane oxidizing bacteria.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  The plant growth promoter of the present invention retains methane-oxidizing bacteria on a carrier, and the plant growth-promoting method of the present invention using this plant growth promoter uses a carrier to which methane-oxidizing bacteria are attached as a plant group dough. Sprinkle or pour into the soil and oxidize and decompose methane in the soil or methane released from the soil by methane-oxidizing bacteria to convert it into carbon dioxide, so that the atmospheric carbon dioxide concentration of the plant population is higher than the surroundings Yes.

  Methane-oxidizing bacteria, also called methane-utilizing bacteria, are microorganisms. The methane oxidizing bacterium used in the present invention is not particularly limited as long as it is a bacterium that uses methane as a carbon source and can finally decompose methane into carbon dioxide and water. Such microorganisms are already known (Appl. Environ. Microbiol., Vol. 65 (11), pp. 4887-4897, 1999), for example, the genus Methylococcus, the genus Methylopsphaera, the genus Methylomobium, the genus Methylomicrobium, , The genus Methylosinus, the genus Methylocystis, and the genus Methanotropic, and the methane oxidizing bacteria used in the present invention are preferably Hyphomicrodium methylovorum, Hyphomicrobium facilis, and Hyphobium belonging to the same cluster. Strains isolated as S4, consisting of T2-06, T2-07, T2-17, and strains closely related to these, classified as type II methane-oxidizing bacteria, and oxidatively decompose methane It is a bacterium that has the ability to do so (hereinafter referred to as methane oxidation ability).

  These methane-oxidizing bacteria are known to live widely in wetlands, lakes and rivers, paddy fields, upland fields, pastures, broad-leaved forest soils and water. It has been confirmed that it inhabits even in the submarine mud.

  Methane-oxidizing bacteria can be obtained by collecting soil from paddy fields with high methane generation, wetlands in lakes, riverside wetlands in agricultural waterways, etc., and culturing them using methane as the sole carbon source. As the methane-oxidizing bacterium used in the present invention, it is preferable to select a methane-oxidizing bacterium having a higher methane oxidation ability.

  Since methane-oxidizing bacteria decompose methane into carbon dioxide and water, methane-oxidizing bacteria can be selected using methane consumption and carbon dioxide generation as indicators. Methane oxidizing bacteria can be cultured according to the method for separating chloroethylene and chloroethane-degrading bacteria by Yagi et al. (National Institute for Environmental Studies Special Research Report SR-31-2000, 2000).

  Specifically, it can be carried out as follows. First, an inorganic salt liquid medium suitable for culturing methane-oxidizing bacteria is placed in a gas vial, and soil is further added and sealed with a vial. Next, after partially extracting the air in the head space of the gas vial, methane is added as a carbon source. This is cultured with shaking in a constant temperature incubator at 30 ° C. After culturing for a certain period, air is collected from the head space, and the methane concentration is measured with a gas chromatograph. About what the reduction | decrease of methane density | concentration was recognized, the liquid culture medium is added to the gas vial containing a liquid culture medium, and a 2nd shake culture is performed. In this culture, a methane-oxidizing bacterium having a large decrease in methane concentration is selected. Further, the methane-oxidizing bacterium having a large decrease in methane concentration is selected by performing planting in a new liquid medium and performing a third enrichment culture.

  The plant growth promoter of the present invention is one in which methane oxidizing bacteria are held on a carrier. In the present invention, as the carrier material, a material capable of holding methane-oxidizing bacteria, that is, allowing methane-oxidizing bacteria to adhere and propagate is used. And it is preferable that a porous material is used in order to promote the propagation of methane oxidizing bacteria. Specifically, for example, charcoal, activated carbon, and rice husk charcoal are preferable.

  For example, when charcoal is used, the wood is made into chips with a particle size of 1 to 100 mm, preferably about 5 to 10 mm, and is usually porous by being carbonized at 300 to 1000 ° C., preferably 400 ° C. or more. A carrier is obtained.

  Moreover, since waste can be effectively utilized by simple treatment, it is preferable to use rice husk treated with charcoal as a carrier. In addition, rice husks are preferably used as the carrier material because rice husks are decomposed in the soil and thus there is no risk of soil contamination. In addition, rice husk is preferably used as the carrier material because organic matter is supplied to the soil to become a fertilizer for plant growth. Furthermore, the use of rice husk as a carrier material allows the silicic acid contained in the rice husk to be supplied to the soil, which is absorbed by the paddy rice and the silicic acid effect such as enhancement of the physical strength of the paddy rice can be obtained. It is preferable to use rice husk.

  When producing a carrier to which methane-oxidizing bacteria are attached and propagated, that is, the plant growth promoter of the present invention, from the viewpoint of practical use such as cost, the smallest amount of methane-oxidizing bacteria is efficiently attached to the whole carrier and propagated. It is preferable to make it. Therefore, a nutrient solution containing methane oxidizing bacteria is added to the upper part of the carrier, and air containing methane is circulated to promote adhesion and propagation on the carrier. Specifically, for example, the following method can be considered.

(1) An inorganic salt medium is sprayed on the carrier and sufficiently moistened to a moisture content of about 80%.
(2) Put the carrier of (1) in a sealable container and add a culture solution containing methane-oxidizing bacteria from the top.
(3) The inside air is evacuated with a vacuum pump, and a mixed gas having a methane / air ratio of 1: 9 is injected.
(4) Operate a fan and circulate air containing methane.
(5) The container is kept at a temperature of about 30 ° C.

  In the propagation of methane oxidizing bacteria, an environment in which the initial methane concentration is 5 to 45 vol%, the ambient temperature is 20 to 40 ° C., and the oxygen concentration is maintained at least 5 vol%, preferably 8 vol% or more is suitable.

  After completion of the operations (1) to (5), the internal methane concentration and carbon dioxide concentration are measured over time, and the air circulation is stopped when the methane concentration falls below the detection limit. As a result, a plant growth promoter in which methane-oxidizing bacteria adhere to and propagate on the carrier is obtained.

And, as shown in FIG. 1, the plant growth promoting method of the present invention uses a plant growth promoting agent 1 in which a methane-oxidizing bacterium 1a obtained by the above-described method is held on a carrier 1b, such as paddy rice, that is, paddy rice group dough Sprinkle or pour into soil 2 of the plant community. The amount of the plant growth promoter 1 to be sprayed or drowned varies depending on the methane concentration in the soil 2 of the plant group dough and the methane oxidation ability of the methane oxidizing bacteria 1a. Specifically, for example, when rice husk treated with charcoal is used as the carrier 1b, it is about 100 to 50 kg, preferably about ^{2 to} 25 kg per m ² . Moreover, when the methane oxidation ability falls with progress of time, the additional growth of the plant growth promoter 1 is suitably performed.

  In addition, when the plant growth promoter 1 is put into the paddy soil 2, it is preferably sprayed or put on the surface layer of the soil 2, that is, the oxidized layer. As a result, methane generated from the organic matter by the action of the methanogen in the reduction layer below the oxide layer can be oxidatively decomposed into carbon dioxide in the oxide layer before being released into the atmosphere. Note that the methanogen refers to a bacterium having an ability to produce methane.

By spraying or swallowing the plant growth promoter 1 described above on the soil 2 of the plant group dough, methane generated from the organic matter in the soil 2 is oxidatively decomposed and converted to carbon dioxide, and carbon dioxide is released from the soil 2 Thus, the atmospheric carbon dioxide concentration of the plant group dough can be made higher than the ambient atmospheric carbon dioxide concentration. And the photosynthesis speed | rate of a plant can be increased by the raise of the atmospheric carbon dioxide density | concentration of a plant group cloth | dough, and growth can be promoted. In addition, for example, a steady methane flux of ²⁰ gCH ₄ / m ² / month is generated from paddy fields (Agricultural Environment Technology Laboratory: Methane generation from paddy fields in Thailand, FY 1995 Agricultural Environment Research Result Information (12th Collection), (1996) all the methane generated along with oxidative decomposition into carbon dioxide, and the active plant ventilation itself is suppressed by the plant itself acting as a wall (specifically 0.5 times) / Hour), an increase in atmospheric carbon dioxide concentration of 32 ppm is expected. Furthermore, according to existing experimental data, the yield of rice (number of spikes / number of pods) has increased by about 15% due to an increase in atmospheric carbon dioxide concentration by 300 ppm (Non-patent Document 2). From these facts, an increase in rice yield of about 1.5% is expected with an increase in the atmospheric carbon dioxide concentration of 32 ppm.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention.

It is a figure which shows the outline | summary of the plant growth promotion method of this invention, and the schematic structure of a plant growth promoter. It is a figure explaining the relationship between the atmospheric carbon dioxide density | concentration of plant-group dough and the photosynthesis rate of a plant leaf.

Explanation of symbols

1 Plant Growth Promoter 1a Methane Oxidizing Bacteria 1b Carrier 2 Soil

Claims (4)

  Scattering or swallowing the carrier with the methane oxidizing bacteria attached to the soil of the plant group dough, converting the methane in the soil or methane released from the soil by the methane oxidizing bacteria into carbon dioxide by oxidative decomposition, A method for promoting plant growth, comprising increasing the atmospheric carbon dioxide concentration of a plant group dough more than the surroundings.   A plant growth promoting method, wherein the carrier is an organic carbide.   A plant growth promoter that holds methane-oxidizing bacteria on a carrier. A plant growth promoter characterized in that the carrier is an organic carbide.

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