A team of researchers from the Korea Electrotechnology Research Institute (KERI) has developed technology for eliminating pests present in soil using microwave heating.

In a bid to protect farms from soil diseases caused by pests such as soil-borne bacteria, fungi and nematodes, which reduce crop yield and quality without employing commonly used pesticides — which destroy agricultural ecosystems, lead to pesticide resistance and leave behind toxic residues — the KERI team has created microwave tech that penetrates soil.

Source: KERI

The KERI-developed device, according to its developers, penetrates microwaves into the ground to heat soil moisture, thereby destroying such pests that are vulnerable to heat.

While efforts using microwave heating for soil remediation have been undertaken by other researchers, the penetration depth achieved to date was, at most, 10 cm deep due to wave diffraction. As such, microwaves are only used for limited applications such as weed control.

However, the KERI team of researchers has adjusted the spatial distribution of microwaves by increasing or decreasing the wavelength and phase according to the intention of the application. To accomplish this, a proprietary antenna — or radiator — was developed for enhancing microwave penetration.

The researchers explained that the microwaves emitted from the antenna are encouraged to meet and overlap at a set point underground. Further, coherently superimposed microwaves increase the amplitude and subsequently heat the soil down to 30 cm or more — in what the team claims is the highest level of technology in the world.

As they travel underground, the microwaves selectively heat the moisture to roughly 60° C to 100° C. Because moisture makes up for an estimated 10% to 30% of the soil and the majority of pests live near the roots of crops and are heat-vulnerable, KERI's microwave technology is likely to be an extremely effective sterilization tool.

According to its developers, the microwave heating technology might also be appropriate for eliminating the habitats of foreign pests found in ports and airports, nondestructively. Likewise, the microwave heating devices could potentially be mounted on vehicles to remove black ice from roads during the winter months or cleaning soil contaminated with oil.