Active Oxygen Enables Simple Decomposition and Disinfection of Soil Fungi

In recent years, demand for soil sterilization and disinfection has been increasing in agriculture due to continuous crop damage and soil damage caused by torrential rainfall, but there is currently no low-cost, effective disinfection method.

(Location: Otsu City, Shiga Prefecture; Representative Director: Akira Aoyama), which has the world's leading patented technology for generating active oxygen from oxygen in the air, has conducted tests to see if soil sterilization and disinfection is also possible since active oxygen effectively kills airborne bacteria and viruses. The test results showed that a short time supply of active oxygen was effective.

Purpose and Methods of Soil Sterilization and Disinfection

Soil disinfection is used to

Avoiding continuous crop damage

Reduction of soil diseases

Reduction of soil diseases

Reduction of soil diseases, and reduction of damage caused by insect pests.

The methods include

Physical control (using solar heat, etc.)

Chemical control (using chemicals)

Biological control (using anti-cellulose crops, etc.)

Biological control (using anti-coccidiosis crops, etc.)

In recent years, greenhouse cultivation has been on the increase. In greenhouse cultivation, soil pests and diseases that prefer certain crops are proliferating in large numbers due to the continuous supply of these crops in successive crops, outcompeting other soil microorganisms and insects. In addition, when fields are flooded by torrential rains, which have been occurring frequently in recent years, there is concern about the outbreak of diseases caused by plague bacteria.

Problems with Soil Sterilization and Disinfection

Soil disinfection has the following problems

Excessive or incorrect use of chemical soil disinfection can affect the soil ecosystem.

The physical treatment of soil disinfection, such as hot water and steam disinfection, is costly in terms of equipment, fuel, and water costs.

Hot water and steam disinfection involve hazardous work for installation and operation.

Solar disinfection can only be effective up to a depth of about 20 cm in the soil

Solar disinfection can mix with pathogens deeper into the soil when plowing.

Considering the environment, safety, and cost, it can be said that there is no effective method at present.

■Soil sterilization and disinfection by active oxygen

We conducted tests at our test farm as shown in the figure below.

(1) Diagram of the test

A vinyl chloride pipe with a blowout opening at its tip was attached to the AOS activated oxygen generator (compact test type),

The vinyl chloride tube was attached to the AOS (small test type) with a blowout opening at the end so that active oxygen would be emitted into the soil from the blowout opening.

The vinyl chloride tube was inserted near the bottom of the ridges in the field, and air was injected into the soil using a compressor.

The injection time was set to 10 minutes.

(2) Entire test

(3)AOS and compressor

(4)AOS test apparatus

Active oxygen generator "AOS-III-T" (for testing)

DC12V, 700L/min (supply volume)

AOS" can generate up to 3000L/min depending on the type

Test results

Soil InsertionAt 50 cm and 100 cm away from the AOS pipe, soil was collected at a depth of x 20 cm with a 40⏀ pipe and analyzed by SOFIX Agricultural Promotion Organization.SOFIX shows how many hundreds of millions of microorganisms (bacteria) are in 1 g of soil. Bacterial DNA is extracted from the soil and the total number of bacteria is measured using the amount of DNA as an indicator. This is called the environmental gene (eDNA) analysis method. eDNA method can also accurately measure bacteria (VBNC) that cannot be cultured.

Total number of bacteria in the soil before the test

(5)Total number of bacteria before the test

(6)Total number of bacteria after the test

Bacterial count in soil before treatment test: 1.64 billion cells/g

Treated soil (50 cm away): 300 million cells/g 82% eliminated

Treated soil (100 cm away): 0.76 billion cells/g, 52% eliminated

The sterilization effect of active oxygen in the air had been confirmed, but now we have confirmed that it also has a sterilizing and disinfecting effect in the soil.

■Mechanism of soil sterilization by active oxygen

Our active oxygen generator "AOS" generates a large amount of active oxygen (superoxide) simply by allowing air (oxygen) to pass through it.

(7)Explanation of AOS

Superoxide reacts with water in the soil and water (protons) from bacteria and microorganisms to produce HO2 (hydroperoxyl radical) and many other reactive oxygen species.

When the large amount of superoxide generated by AOS is released into the soil, it reacts with the moisture in the soil and the moisture in the cells of bacteria and microorganisms, becoming powerful reactive oxygen species that instantly destroy and decompose the cells of bacteria and microorganisms. The AOS-treated air injected into the ridges is filled with active oxygen, and all bacteria and microorganisms that come into contact with it are decomposed and eliminated.

Future Development

The AOS is characterized by its ability to generate a large amount of active oxygen in the atmosphere at low cost; a single unit can generate up to 3000 L/min of active oxygen.

Therefore, mechanization of soil sterilization and disinfection is relatively simple.

Company Profile

Company name: WEF Technology Development Co.

Representative: Akira Aoyama, President

Location ： 1-19-15 Do, Otsu-shi, Shiga

Establishment ： July 2016

Business description: Development and sales of water treatment, waste recycling, and Mg-related technologies

URL ： https://aoyama-wefit.com