JPH119091A - Control of pest in soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and simply control pests in soil without damaging crops and without polluting environments by supplying warm water into soil from a watering pipe set in the soil near to the rooting zone depths of the crops to heat the soil at a prescribed temperature of higher, before the crops are sowed, etc. SOLUTION: This method for controlling pests such as soil nematodes parasitizing in plants in soil comprises supplying dissolved oxygen-removed warm water (the temperature is preferably <=40 deg.C, and the concentration of the dissolved oxygen is <=4 ppm) into soil from a watering pipe 3 set in the soil 4 near to the rooting zone depth of crops to raise the temperature of the soil in places ranging from the rooting zone of the crops to a place 5 cm deep from the surface of the ground by 30 deg.C or higher, before the crops or crop seedlings are sowed or transplanted. The warm water free from the dissolved oxygen is preferably supplied into the soil at a flow rate of <=3.0 cm<3> /sec per meter of the watering pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling pests in soil, and more particularly, to a method for safely and labor-saving harmful to agricultural crops by supplying warm water from which dissolved oxygen has been removed. The present invention relates to a pest control method capable of controlling organisms in soil.

[0002]

2. Description of the Related Art In the field of agriculture and horticulture, damage to crops caused by soil nematodes, soil disease fungi, insects and their larvae in the soil, or small animals is enormous, and often destroys crops. Disable continuous cropping. Therefore, measures such as rotation, rotation, and suspension of work are unavoidably taken. In order to avoid such a situation, soil pest control agents such as soil insecticides and soil fungicides have conventionally been used. Further, in facility cultivation, soil disinfection using solar heat or hot water is also performed.

[0003] Soil pest control agents need to be distributed as uniformly as possible over a certain depth of the soil. Therefore, in the case of powder, it is necessary to disperse in the soil by plowing or the like. In addition, in the case of liquid, since the chemical does not penetrate to a sufficient depth of the soil when applied from the ground surface, a method is used in which holes are formed at regular intervals in the field surface, and small amounts are injected into individual holes. .

[0004] In particular, as a soil pest control agent, from the viewpoint of uniformly distributing the active ingredient in the soil, fumigation pesticides in which the active ingredient volatilizes in the soil, for example, chlorpicrin,
Methyl bromide is frequently used. However,
Many soil pest control agents are harmful to crops and the human body, and require careful safety measures and much labor for application.
Further, it is necessary to remove the harmful chemicals from the soil by plowing or the like before sowing or planting.

[0005] In addition, there is a possibility that the chemicals may adversely affect the environment such as polluting groundwater. Furthermore, the organisms to be controlled are acquiring resistance to existing drugs, and the effects of the drugs are weakening. For this reason, the current situation is to respond by spraying more than the specified amount of the drug, and even if a new drug is developed, it will only temporarily survive until the target organism gains resistance to the drug. There is no denying the fear of disappearing.

[0006] Soil disinfection by solar heat is performed by flooding a field with a large amount of water, covering the ground surface with mulching or the like, and then closing the facility. On a sunny day, the temperature inside the facility is 6
It reaches 0 ° C. Along with this, the soil temperature in the field also rises, and soil can be disinfected. However, soil disinfection by solar heat has a problem that seeding and planting cannot be performed as planned because the disinfection depends on the weather, and the effect of disinfection using solar heat appears near the ground surface and the ground surface. Because it is limited to very shallow areas, other disinfection methods must be used in combination to disinfect all soil in the field.

[0007] For example, soil disinfection by hot water is a method in which high-temperature hot water is continuously sprayed on the soil surface to increase the underground temperature. For example, in Japanese Patent Publication No. 7-63280, the temperature is 80 ° C.
Is used to raise the underground temperature to 55 ° C. JP-B-48-34870 and JP-A-57-152828 disclose methods of injecting high-temperature hot water into soil to increase the underground temperature.
However, these methods require a very high temperature and a large amount of irrigation in order to obtain the target temperature of the soil, and require a great deal of equipment and operation costs to achieve a sufficient effect.

[0008]

The problem to be solved by the present invention is to provide a safe, environmentally friendly, simple and low-cost method for effectively controlling pests in soil without damaging crops. An object of the present invention is to provide a method for controlling pests in soil.

[0009]

Means for Solving the Problems The present inventors irrigate the ground with warm water from which dissolved oxygen has been removed, and raise the ground temperature in the vicinity of the rhizosphere in the soil to 30 ° C. or higher, thereby reducing harmful effects in the soil. It has been found that organisms, particularly plant parasitic nematodes, can be effectively controlled, and the present invention has been completed.

[0010] That is, the present invention provides (1) supplying warm water from which dissolved oxygen has been removed from a watering pipe installed in soil near the depth of the rhizosphere of a crop before sowing or planting the crop; The temperature from around the rhizosphere to 5cm below the surface of the ground
(2) The method for controlling pests in soil characterized by raising the temperature to 0 ° C or higher, (2) the temperature of warm water from which dissolved oxygen has been removed is 40 ° C or higher, Pest control method,

(3) By supplying hot water from which the dissolved oxygen has been removed from the irrigation pipe installed in the soil near the depth of the rhizosphere of the crop during the growth of the crop, from the vicinity of the rhizosphere of the crop to 5 cm below the ground surface. A method for controlling pests in soil, which comprises raising the temperature to 30 ° C. or higher, (4) The temperature according to (3), wherein the temperature of hot water from which dissolved oxygen has been removed is 40 ° C. or lower. Pest control method in soil,

(5) The pest in the soil according to any one of the above (1) to (4), wherein the dissolved oxygen concentration of the warm water from which the dissolved oxygen has been removed is 4 ppm or less. (6) The supply flow rate of warm water from which dissolved oxygen was removed to soil was 3.0 cm ³ / m per irrigation pipe.
The method for controlling pests in soil according to any one of (1) to (4) above, wherein the pests are plant parasitic soil nematodes. The method for controlling pests in soil according to any one of the above (1) to (4), which is characterized in that there is a certain method.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for controlling pests in soil according to the present invention will be described in detail. The method for controlling pests in soil according to the present invention comprises supplying raw water from an arbitrary water source such as a tap or a well to a deoxygenated water producing apparatus, preparing deaerated water from which dissolved oxygen in the raw water has been removed, and then preparing the deaerated water. Deaired temperature water obtained by heating deaerated water with a heating device is irrigated into soil through an irrigation pipe.

The deoxidized water producing apparatus of the present invention is used for:
As a method for removing dissolved oxygen from water, a known and commonly used method is used. As a preferable simple example, for example, a membrane-type vacuum deoxygenation method described in JP-A-63-258605 can be mentioned. In this method, raw water is passed through one of the membranes through which gas can pass but liquid cannot pass, and the other is depressurized.

In addition, a membrane oxygen absorption method in which raw water and an oxygen adsorbent are brought into contact with each other through a membrane through which a gas can pass but a liquid cannot pass, a so-called vacuum deoxygenation method in which the pressure in a packed tower or a spray tower is reduced, Various methods have been disclosed, such as a thermal deoxidation method utilizing a decrease in the solubility of a gas with a rise in temperature, a method of bubbling a gas other than oxygen, and an ultrasonic deoxygenation method. In the present invention, these existing methods can be appropriately used.

Above all, the membrane vacuum deoxidation method and the vacuum deoxygenation method are preferable, and the membrane vacuum deoxygenation method is more preferable, because the apparatus is simple and the operation cost is low. The membrane-type vacuum deoxygenation method has such advantages that the device can be made relatively small, the device can be easily handled, and the dissolved oxygen can be removed to a high degree. The membrane used in the membrane-type vacuum deoxygenation method can be any membrane as long as it can pass gas but cannot pass liquid.However, hollow fibers can be used because the size of the apparatus can be further reduced. Membranes are preferred.

Among them, the inner diameter of the hollow fiber membrane used is 250 μm.
m or less is more preferable. Further, a hollow fiber membrane having a heterogeneous structure has a higher gas passage speed than a homogeneous membrane, and is therefore more suitable as a deoxygenation membrane.
Examples of the material of the membrane include poly-4-methyl-1-pentene, which is hydrophobic, has a high gas passage rate, and has high strength.

As the vacuum device, existing devices such as various vacuum pumps and aspirators can be appropriately used. Among them, a simple water ring vacuum pump, a diaphragm vacuum pump, a dry vacuum pump, a water aspirator, etc. Is preferred because it can withstand a large amount of water vapor.

The amount of dissolved oxygen in the warm water from which dissolved oxygen has been removed is preferably 50% or less, more preferably 30% or less, even more preferably 10% or less of the saturated dissolved oxygen concentration. Specifically, the dissolved oxygen concentration of warm water from which dissolved oxygen has been removed is 4 ppm or less, preferably 3 ppm or less.
pm or less, more preferably 1 ppm or less. In order to prevent redissolution of oxygen, the produced deoxygenated water is desirably protected from the atmosphere and stored, or is used immediately after production, that is, it is desirable to warm and irrigate the soil.

The apparatus for producing hot water is not particularly limited, and boilers and electric water heaters using heavy oil, kerosene, LPG or the like as fuel can be suitably used. However, a water heater using solar heat may be used. However, the hot water production device must be capable of producing hot water at a required temperature in accordance with the area of the field to be controlled and the timing of performing the treatment. The supply of warm water to the soil is performed by an irrigation pipe installed near the rhizosphere depth of the crop in ordinary soil such as a field or a greenhouse.

It is said that the optimum inhabiting temperature of normal pests in soil is from 20 ° C. to 30 ° C. For example, in the case of nematodes, the temperature easily exceeds 45 ° C., preferably 50 ° C. or more. It is known to die. However, in consideration of the effect on the crop plant, the temperature of the hot water in contact with the plant is preferably 40 ° C. or lower. The present invention uses hot water from which dissolved oxygen has been removed to enhance the harmfulness to pests in the soil, thereby irrigating the soil with de-aired water at a temperature of 40 ° C. or less, and raising the temperature of the soil to 30 ° C. or more. Raising can provide sufficient damage to pests in the soil.

Although the detailed mechanism is not clear, hot water from which dissolved oxygen has been removed not only has a direct damaging effect on pests due to temperature, but also has the effect of increasing the soil temperature to increase the metabolism of pests in soil. It is thought that the pests can be hit more effectively by increasing the oxygen demand of the pests and reducing the oxygen supply in the soil at once.

Before sowing or planting a crop, hot water from which the dissolved oxygen has been removed is supplied from an irrigation pipe installed in the soil near the depth of the rhizosphere of the crop, so that the ground surface can be measured from the depth near the rhizosphere of the crop. The higher the temperature of warm water used to raise the temperature from water to a depth of 5 cm to 30 ° C. or higher, the faster the temperature in the ground rises, and the greater the effect on pests in the soil. On the other hand, if the temperature of the hot water is too low, it is difficult to raise the temperature of the soil above the optimum temperature condition for controlling pests in the soil.
C. or higher is more preferable, and 50 C or higher is more preferable.

In supplying hot water for the purpose of controlling pests in the soil before sowing or planting the crops on the soil, it is particularly necessary to specify the upper limit of the temperature of the hot water to be used as long as it is lower than the boiling point of water. However, raising the temperature of hot water extremely requires the use of high heat-resistant members such as iron pipes in the piping of hot water, which is expensive and labor-intensive, and is not preferable. It is as follows.

On the other hand, after the crop is sown or planted in the soil, while the crop is growing, hot water from which dissolved oxygen has been removed is supplied from an irrigation pipe installed in the soil, so that the crop is 5 cm below the ground from near the rhizosphere of the crop. When the temperature of the soil up to 30 ° C or more is actually raised to about 30 ° C, it is necessary to avoid supplying high-temperature hot water that affects crops to the vicinity of the roots. The temperature is 50
C. or lower, preferably 40 ° C. or lower.

The depth of the installed irrigation pipe from the surface is
It depends on the depth of the rhizosphere of the crop to be made and cannot be specified unconditionally, but in general, it is sufficient to install an irrigation pipe at a depth of about 60 cm from the ground surface. For example, the roots of tomato, cucumber, melon and the like are relatively shallow, about 15 to 30 cm, but the root vegetables are deeper and 30 to 50 c.
m.

From the viewpoint of avoiding direct contact of the crop roots with hot water during the supply of warm water during the growing period of the crop, if the tomato, cucumber, melon or the like is used, an additional 10 c.
m depth, that is, 20-30cm depth from the ground
It is preferable to install the irrigation pipe at about 40 to 60 cm for root vegetables. It is preferable to select a cropland or greenhouse in which pipes are arranged at about two different depths, and use them properly according to the crop type.

Raising the temperature from the vicinity of the crop rhizosphere to 5 cm below the ground surface to 30 ° C. or higher means that the warm water supplied from the irrigation pipe installed near the crop rhizosphere removes the soil from the vicinity of the crop rhizosphere. Means raising the temperature of the soil existing up to a depth of 5 cm from the ground surface to 30 ° C. or more.

Here, 5 cm below the ground without setting the temperature of the ground
The temperature of 5cm below the surface, which is hardly affected by the weather conditions of the surface, is used because the temperature of the surface rises under direct sunlight in summer and does not reflect the correct temperature in the ground. This does not exclude from the present invention that the temperature of the soil from the site 5 cm below the ground surface, that is, 5 cm deep from the ground surface to the ground surface, becomes 30 ° C. or more, and the soil temperature of the portion also becomes lower. The temperature is preferably 30 ° C. or higher, and the present invention includes that the temperature of the soil between the site having a depth of 5 cm from the ground surface and the ground surface is 30 ° C. or higher.

Supplying hot water using an irrigation pipe installed in the ground at the center of a ridge for sowing or planting crops is efficient in that heat of the hot water does not escape to the atmosphere. Irrigation from the ground is preferable because oxygen in the atmosphere can be prevented from dissolving in warm water. FIG.
Fig. 1 shows an example in which an irrigation pipe is installed underground in the method for controlling pests in soil according to the present invention.

First, the irrigation pipe 3 is buried along the center of the ridge 5 for sowing or planting a crop. One end 3a of the irrigation pipe 3 is sealed. From the other end 3 b of the watering pipe 3, hot water from which dissolved oxygen has been removed is supplied into the surrounding soil 4 through the watering pipe 3. Thereby, the soil 4 inside the ridge 5 in which the irrigation pipe 3 is buried is provided.
Is uniformly irrigated, the temperature of the soil rises, and pests in the soil, that is, small animals such as moles and rats, soil nematodes,
It can control soil disease fungi, insects and their larvae.

As the irrigation pipe, a porous pipe, a vinyl chloride pipe with many holes, a vinyl hose with holes at regular intervals, and a plastic pipe with a constant flow rate at regular intervals were drilled. A so-called drip irrigation pipe or the like can be used as appropriate. Among them, a porous tube is preferably used. As the porous tube, a tube made of plastic, ceramics, or even a sintered material may be used.However, a porous tube using a flexible material such as rubber is preferable in terms of workability and economy. preferable.

As an example of a porous tube suitably used in the control method of the present invention, Japanese Patent Application Laid-Open No. 7-1 filed earlier by the present applicant.
A porous tube described in detail in Japanese Patent No. 55060 can be mentioned. This porous tube is preferably formed of a flexible material, for example, a plastic such as rubber, polyvinyl chloride or polyethylene, or a composite material thereof. In particular, a rubber powder molded using a binder such as polyethylene is preferable.

Fine continuous through holes are formed in the tube wall of the porous tube, and the porosity is preferably about 30%. Since this porous tube is used by being buried in the soil and constantly in contact with water and ionic components in the soil, it is preferably flexible and noncorrosive. Is not very suitable as a material in terms of breakage, corrosion, and product weight. Since the porous tube may be roughly handled during or after embedding, it preferably has a certain strength, for example, a tensile strength (JIS K6301) of about 15 kg / cm ² or more,
As a specific example of the porous tube that can be suitably used in the present invention, for example, “Leaky Pipe” (registered trademark: manufactured by Nippon Sanso Corporation) can be mentioned.

Irrigation with warm water from which dissolved oxygen has been removed is preferably carried out prior to planting or sowing of the crop. The amount of irrigation varies depending on the method, area, treatment time, and the like of irrigation, but it is preferable to irrigation at least 30 mm rainfall equivalent. It is more effective to insert a thermocouple-type thermometer in the ground and to perform watering while monitoring the ground temperature. In conjunction with underground irrigation, irrigation of the surface with warm water along the center of the ridges where the crops are sown or planted is also effective in raising the temperature in the soil. Further, at any time of irrigation, the effect can be further enhanced by coating the soil surface with vinyl or the like.

The water underground irrigated with a watering pipe in the soil is
Immediately penetrates into the soil, spreads in the soil by downward movement by gravity and parallel movement by capillary action, and raises the temperature of the surrounding soil. At this time, the movement of the warm water through the soil is affected by the quality of the soil, the dry state, and the intensity of the warm water irrigation. That is, if the flow rate of the hot water is increased, the temperature of the soil can be raised in a short time, but the falling phenomenon due to gravity becomes remarkable.

On the other hand, it is preferable to perform the irrigation at a low flow rate because the hot water can move concentrically around the irrigation pipe by capillary action, depending on the water content of the soil. However, if the flow rate is too low, it takes a long time to raise the temperature of the soil to such an extent that pests can be controlled, resulting in high costs. As a result of various examinations of these conditions, it was found that preferable results were obtained when the supply flow rate of hot water from which dissolved oxygen had been removed was not more than about 3.0 cm ³ / sec per 1 m of irrigation pipe. This is equivalent to the flow rate when 100 mm rainfall is irrigated in 10 hours.

In the case where hot water from which dissolved oxygen has been removed is supplied from an irrigation pipe during crop growth to control pests,
This is performed under the same conditions as described above. The frequency of irrigation control during cropping depends on the type and season of the crop, and cannot be specified unconditionally.However, in the case of crops that are particularly harmful to nematodes, such as tomatoes, cucumbers, and melons, control the pests before cropping. In addition, it is preferable to control several times during cropping, generally two to three times.

The pests in the soil to be controlled in the present invention are organisms that inhabit the soil and damage crops, fruit trees, flowers, etc., and include, for example, root-knot nematodes and negsare that inhibit the growth of crops. Soil nematodes such as nematodes,
Insects such as moth larvae, scarab beetle larvae and cicada larvae parasitic on roots, and soil disease fungi such as picium, fusarium, rhizoctonia, and partirium that cause soil disease. It is.

[0040]

The present invention will be described below in more detail with reference to examples. (Reference example) Effects of warm water from which dissolved oxygen was removed on sweet potato nematodes ( Meloidogyne incognita ) against second-stage larvae Tap water from which dissolved oxygen was removed (dissolved oxygen concentration about 0.6 pp)
m: deoxygenated water zone) and ordinary tap water (dissolved oxygen concentration about 8)
ppm: tap water section) 6 ml tube bottles (height 4.3c)
m, 1.3 cm in diameter) were prepared, and three of the two stage larvae of the sweet potato root-knot nematode were released and sealed. This was allowed to stand still in a thermostat kept at 20 ° C., and after 2 hours, 4 hours, and 6 hours, the bottles were opened one by one from a tap water section and a deoxygenated water section, and the contents were taken out with a syringe. After transferring to a watch glass, the number of surviving nematodes was examined. A similar experiment was performed with the water temperature of the thermostat kept at 35 ° C.
The survival rate of each nematode is shown in FIG.

The vertical axis of FIG. 2 represents the survival rate (%) of the nematodes, and the horizontal axis represents the holding time (hour) in a thermostat. As is clear from FIG. 2, in tap water at a temperature of 20 ° C. (tap water at 20 ° C.), the nematode is almost alive even after 6 hours, whereas tap water at a temperature raised to 35 ° C. In the case of tap water (35 ° C.), the survival rate was reduced to about 80%, and in the case of tap water at a temperature of 20 ° C. (deoxygenated water at 20 ° C.) from which dissolved oxygen was further removed, the survival rate was 50%.
% Of tap water (deoxygenated water 35 ° C) at a temperature of 35 ° C from which dissolved oxygen has been removed, and the survival rate has dropped to about 10%. It has a significant effect on

(Example 1) A control test in a field where sweet potato root-knot nematodes frequently occur A root-knot nematode control test was carried out using a steel frame greenhouse after cultivation of cucumber, which frequently caused root-knot nematodes. For the crop, tomato (cultivar name: House Momotaro) was raised and tested according to a standard method.

As an irrigation treatment plot, room temperature (about 15 ° C.)
First section using well water (control section), second section using room temperature well water without dissolved oxygen (comparative example), third section using well water heated to 50 ° C (Comparative Example) Four sections of a fourth section (Example) using well water excluding dissolved oxygen heated to 50 ° C. were set.

Each test plot had a ridge width of 120 cm and a ridge length of 25 m.
Of a porous tube (leaky pipe, permeability coefficient = 5.4) with one end sealed at the center of each of the four sections.
× 10 ⁻⁶ cm / sec, manufactured by Nippon Sanso Corporation) was buried at a depth of 20 cm. The other end of the porous pipe was connected to a deoxygenated water producing apparatus, a water heater, and a well water outlet through a pipe and a flow meter with a valve. The ridge surface was mulched with agricultural vinyl. Before planting tomatoes in each section, irrigation (60 l / m ² ) was performed at a flow rate of about 0.7 cm ³ / sec per meter of irrigation pipe for about 24 hours, equivalent to about 60 mm of rainfall.

The nematode density of each test plot was measured before and after the watering treatment. The furrow soil was collected at three locations at different depths in each section, mixed thoroughly at each depth, 20 g was taken out, and the number of larvae was detected by Bellman method. Table 1 shows the results of the root-knot nematode second-stage larvae (head / 20 g) before and after the watering treatment. Tomato seedlings were planted on these cultivation beds at intervals of 30 cm between the plants, and cultivated according to customary practices. After the cultivation, the roots were dug up and the degree of damage caused by the nematode in 5 stages (none = 0, fine = 1, small = 2, medium = 3, many =
Cattle index, ｛Σ (degree of damage x)
The number of strains) / 5 × the number of strains to be investigated｝ × 100. Table 2 shows the damage (nekobu index) of the root-knot nematode in each test plot after completion of tomato cultivation.

[0046]

[Table 1]

[0047]

[Table 2]

Example 2 Pest Control Test in a Sweet Potato Nematode Frequently Producing Field Using a sweet potato root-knot nematode frequently occurring field (steel frame greenhouse), a control test of sweet potato root-knot nematodes was performed. As for the crop, tomato (cultivar name: House Momotaro) was used for raising and seedling according to a standard method. Field preparation and irrigation materials were exactly the same as in Example 1.

As an irrigation treatment plot, normal temperature (about 15 ° C)
First section using well water (control section), second section using room temperature well water without dissolved oxygen (comparative example), third section using well water heated to 50 ° C (Comparative Example) Four sections of a fourth section (Example) using well water excluding dissolved oxygen heated to 50 ° C. were set.

In the same manner as in Example 1, the watering treatment was performed as a pre-planting treatment. In each of the plots, before the tomato planting, the flow rate per m of the irrigation pipe was about 0.7 cm ³ / sec for about 24 hours, and the amount of water was about 60 mm. Irrigation treatment (60 l / m ² ) was performed. Further, during the operation, the wells were at room temperature in the first section, room temperature well water deoxygenated in the second section, well water heated to 40 ° C in the third section, and 40 ° C in the fourth section. The deoxygenated water whose temperature had been raised was half watered (every 30 mm rainfall equivalent) of the pre-crop watering volume every two weeks. Cultivated for 4 months.

The nematode density was measured before and after the pre-planting treatment and after the cultivation. Table 3 shows the results of the number of root-knot nematode second-stage larvae (head / 20 g) before and after the pre-planting treatment and after the completion of the cultivation. After the cultivation was completed, the damage (cat swelling index) by the root-knot nematode after the completion of the tomato cultivation was determined in the same manner as in Example 1. This is shown in Table 4.

[0052]

[Table 3]

[0053]

[Table 4]

(Example 3) Larvae control test of bean bugs As in the case of the nematodes, the test plot was used as a test plot for irrigation treatment. The first plot (control plot) using well water at normal temperature (about 15 ° C), the dissolved oxygen The second section using room temperature well water excluding water (Comparative Example), the third section using well water whose temperature was raised to 50 ° C. (Comparative Example), and the well water excluding dissolved oxygen at 50 ° C. Four sections of a fourth section (Example) using the heated one were set.

In each of the test sections, a porous tube (a leaky pipe, having a permeability of 6.2 × 10 ⁻⁶ cm / sec.
(Manufactured by Nippon Sanso Corporation) at a depth of about 20 cm.
Nine mamekogane larvae, each in a net-like bag together with soil, were prepared. Three of these were buried in each test plot at a depth of 10 cm, 20 cm, and 30 cm.
The other end of the porous tube was connected to a water supply source via a pipe and a flow meter with a valve. Irrigation is 1m each pipe
Watering (60 l / m ² ) equivalent to about 60 mm rainfall was performed at a flow rate of about 0.7 cm ³ / sec for 24 hours.

Immediately after the watering treatment, all the bags containing the beetle larvae were collected, and the number of survivors in each test plot was counted. Table 5 shows the results. In Table 5, the control rate was calculated by subtracting the number of surviving larvae in each test plot from the number of surviving larvae in the control plot No. 1 and dividing this by the number of surviving larvae in the control plot.
It was determined by multiplying by 0.

[0057]

[Table 5]

[0058]

INDUSTRIAL APPLICABILITY The present invention provides an excellent control of pests in soil which does not hinder crops, is safe, is environmentally friendly, is simple, and effectively controls pests in soil at low cost. A method can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a case where an irrigation pipe is installed underground in the method for controlling pests in soil according to the present invention.

FIG. 2 is a diagram showing the survival rates of nematodes for each elapsed time at 20 ° C. and 35 ° C. in deoxygenated water and tap water.

[Explanation of symbols]

 3 irrigation pipe 4 soil 5 ridge

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masayuki Taniguchi 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo Inside Nippon Oxide Co., Ltd. (72) Inventor Yuji Fujiwara 2-2 Ebaradai, Sakura City, Chiba Prefecture 7 Diacoat A103 (72) Inventor Taku Fujii 6-5-7 Takahama, Mihama-ku, Chiba City, Chiba Prefecture (72) Inventor Masaaki Masui 594-9, Sakuragicho, Wakaba-ku, Chiba City, Chiba Prefecture

Claims (7)

[Claims] 1. Before sowing or planting a crop, hot water from which dissolved oxygen has been removed is supplied from an irrigation pipe installed in soil near the depth of the rhizosphere of the crop, so that the groundwater is removed from the vicinity of the rhizosphere of the crop. A method for controlling pests in soil, comprising raising the temperature up to 5 cm to 30 ° C. or higher. 2. The temperature of hot water from which dissolved oxygen has been removed is 40 ° C.
The method for controlling pests in soil according to claim 1, wherein: 3. During growth of the crop, hot water from which dissolved oxygen has been removed is supplied from an irrigation pipe installed on the soil near the depth of the rhizosphere of the crop, so that the ground water is removed from the vicinity of the rhizosphere of the crop.
A method for controlling pests in soil, comprising raising the temperature up to 30 ° C. or higher. 4. The temperature of hot water from which dissolved oxygen has been removed is 40.
The method for controlling pests in soil according to claim 3, wherein the temperature is not higher than ℃. 5. The dissolved oxygen concentration of warm water from which dissolved oxygen has been removed is 4 ppm or less.
The method for controlling pests in soil according to any one of the above. 6. The method according to claim 1, wherein the flow rate of the hot water from which dissolved oxygen has been removed to the soil is 3.0 cm ³ / sec or less per 1 m of the irrigation pipe. For controlling pests in soil. 7. The method for controlling pests in soil according to claim 1, wherein the pests are plant parasitic soil nematodes.