JP2000086410A - Improvement of soil microflora - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve soil microflora by applying a hydroxy(methylthio)butyric acid (salt) to soil to decrease plant-parasitic nematode separated from the soil and increase non-plant-parasitic nematode to effect rich soil microflora and inhibit the outbreak of soil disease injury. SOLUTION: Soil microflora is improved by applying 2-hydroxy-4-(methylthio) butyric acid or a salt thereof to soil; wherein the cation constitution the salt of 2-hydroxy-4-(methylthio)butyric acid (HMTB) is pref. an alkali metal such as sodium, alkaline earth metal such as calcium, or ammonium cation or urea; the amount of the HMTB or a salt thereof to be used is <=60 kg/10a so as not to cause chemical injury to crops but >=20 kg/10a so as to bring inhibitory effect against damage due to harmful soil microorganisms; and the HMTB can also be used through mixing with a fertilizer used in terms of an agrochemical or an agrochemical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to 2-hydroxy-4-
The present invention relates to a method for reducing the density of harmful soil microorganisms that damage crops by using (methylthio) butyric acid.

[0002]

2. Description of the Related Art In many cases, chemical pesticides are used to control soil-derived fungi and plant parasitic nematodes that cause great damage to crops. Solar disinfection when pesticides cannot be used,
Alternatively, rotation of crops in which infestation of pathogenic bacteria and nematodes and propagation do not occur is performed.

[0003]

Among the chemical pesticides, fumigants such as methyl bromide, chloropicrin, 1,3-dichloropropene, methyl isothiocyanate and its analog dazomet are excellent in controlling harmful soil microorganisms. . However, crops cannot be planted immediately after treatment due to chemical damage. In addition, since the processing of an order of magnitude more than ordinary pesticides imposes a heavy burden on the environment, such pesticides tend to decrease gradually worldwide. Other pesticides have the advantage of being easy to use and less harmful to crops, but they are poorly dispersed in the soil and have poor ability to control harmful soil microorganisms. Have difficulty.

As a method of controlling harmful soil microorganisms other than pesticides, solar heat disinfection is known. However, this method has large fluctuations in temperature and sunshine due to the year, and it is difficult to stabilize the effect. In addition, there is a drawback in terms of cultivated land utilization because it cannot be settled for a long time. Crop rotation is a method of controlling the damage of harmful soil microorganisms that has been used for a long time, but does not always match modern agriculture, which emphasizes economic efficiency. In addition, the method of controlling harmful soil microorganisms by applying compost or the like cannot expect a sufficient effect in fields where harmful soil microorganisms are widespread. It is difficult to use crops due to acid and other problems.

[0005] It has been reported that the treatment of soil with amino acids reduces crop damage from harmful fungi and nematodes.
v. Phytpathol. 4 (1966) pp. 349-368, NEMATOLOGIC
A 17 (1971), pages 495-500. However, the application rate was large and it was difficult to use it economically. Nor was the amount used to control damage significantly different from that causing crop damage to crops.

[0006]

Means for Solving the Problems The present inventors have studied extensively the effects of organic matter on harmful soil microorganisms, and treated soil with 2-hydroxy-4- (methylthio) butyric acid (hereinafter referred to as HMTB) or a salt thereof. In this case, we found that the number of plant parasitic nematodes isolated from the soil decreased, and that the number of non-plant parasitic nematodes increased, thereby enriching the soil microflora and suppressing the occurrence of soil diseases. . HMTB is highly soluble in water, is inexpensive, and is rapidly and efficiently converted to methionine by animals after ingestion. Used in

It has not been known to date that the treatment of soil with HMTB or a salt thereof suppresses crop damage caused by harmful soil microorganisms. That is, the present invention
This is a method for improving soil microflora, which comprises treating MTB or a salt thereof with soil.

The cation constituting the salt of HMTB is preferably an alkali metal such as sodium or potassium, an alkaline earth metal such as calcium or magnesium, an ammonium cation, or urea. The amount of HMTB or salt used is 60 kg / 1 which does not cause harm to crops.
0a or less, and 20kg / 10a or more, at which the effect of suppressing damage caused by harmful soil microorganisms appears. HMTB can also be used by mixing with fertilizers used for pesticides or pesticides.

HMTB or its salt has no effect on the growth of crops in the above range, and has a high solubility in water and can be dissolved in irrigation water for easy treatment. Enables control of harmful soil microorganisms during crop growth. In addition, the effect of HMTB can be improved by activating the microbial activity by securing the temperature by coating and irrigating.

[0010]

Example 1 Influence of HMTB and Additives 1 × 10 ⁴ spores / g of spores of Fusarium oxysporum f.sp. Further, 0.4 g of HMTB or a salt thereof and 3 g of a chemical fertilizer containing 7.5% each of nitrogen, phosphoric acid and potassium were added and mixed well. After mixing, the mixture was packed in a polyethylene bag, allowed to stand in a 25 ° C. artificial weather vessel for one week, and mixed again, after which nematodes were separated by the Berman method. 0.2 g of dazomet was used as a control drug. Table 1 shows the average results of the two repetitions of each treatment.

[0011]

[Table 1]

Further, the soil was packed in a polyethylene pot having a diameter of 10.5 cm, and two tomato seedlings were planted per pot. After cultivation at 25 ° C. for one month, the weight of the above-ground part and the cat root formed on the root were determined based on the degree of infestation shown below. In the test for radish yellow blight, 10 radish seeds were sown in a 7.5 cm polyethylene pot, thinned out one week later, and then cultivated in a pot.
After making the book, the number of diseased seedlings was counted 6 weeks after sowing. In the Dazomet treatment area, the tomatoes died due to chemical damage, so they were replanted one week later. Radish did not germinate, so 1
After one week, the soil was mixed again, left for one week, and sown. Table 2 shows the average results of two treatments of each nematode and two treatments.
Table 3 shows that the number of cases without repetition in the test for radish yellow rot was shown in Table 3.
Shown in

[0013]

[Table 2] Nekobu infestation degree in Table 2 0: No Nekobu 0.5: Nekobu is 12.5% or less of root system 1: Nekobu is more than 12.5% of root system and 25% or less 1.5: Nekobu is more than 25% of root system and 37.5% Less than 2: Nekobu is more than 37.5% and less than 50% of the root system. 2.5: Nekobu is more than 50% and less than 62.5% of the root system. 3: Nekobu is more than 62.5% and less than 75% of the root system. More than 75% of root system and 87.5% or less 4: Nekobu is 87.5% or more of root system

[0014]

[Table 3]

[0015]

According to the present invention, 2-methionine is easily converted to methionine by an organism, and is easily eliminated by an organism in a normal environment.
Using hydroxy-4- (methylthio) butyric acid or a salt thereof, the crop could be protected from harmful soil microorganisms without causing phytotoxicity to the crop.

Continuation of the front page (72) Inventor Hiroshi Kawata 66-2 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa F-term (reference) 4H011 AA01 AC01

Claims (1)

[Claims] 1. A method for improving soil microflora, comprising treating soil with 2-hydroxy-4 (methylthio) butyric acid or a salt thereof.