# Applications of Plasma Produced with Electrical Discharges in Gases for Agriculture and Biomedicine
## 3 Review of Plasma Applications in Agriculture and Medicine
### Plasma Applications in Agriculture
#### 3.1.2 Agricultural Soil Treatment and Pest Control  
Application of non-thermal plasma in agriculture has recently become an important technique to ensure the safety of plant growth, soil treatment, and food processing. The objective of agricultural soil sterilisation is to destroy or eliminate microbial cells in the soil. A mixture of water-mist with ozone produces very reactive intermediate, hydroxyl free radicals, and reactive oxygen and nitrogen species (RONS), including atomic nitrogen, nitric oxide, peroxynitrite (ONOO-), atomic oxygen, hydroxyl radical, superoxide (O\({}_{2}-\)) and hydrogen peroxide, which are much stronger oxidising agents than ozone itself, and they have great potential in soil and plants treatment and pest removal in agricultural soil [14; 17; 19; 28; 63; 84; 131; 132]. The use of atmospheric plasma as a treatment technique in agriculture has many advantages, including low cost and avoiding chemicals and undesirable changes to agricultural produce related to heat treatment. Soil remediation is a difficult procedure because it must be performed on site and should cover a relatively large surface area with various geological settings, while also maintaining penetration depth. Organic matter has the greatest influence on the sorptive capacity of soils. Apart from organic matter, grain-size distribution is an important factor influencing the sorptive capacity of soils, especially the content of very fine and colloidal particles. The distribution of cations in the sorptive complex depends on pedagesis (soil forming process), which is only their typology. The total exchange of cations in the sorptive complex and the base saturation depend on the type of the parent rock, including the presence of carbonates [133]. The processing of soil depends on several factors including:  
* Type of soil (content of water, organic compounds, consistence, and structure). * Type of pollutant. * Treatment technique. * Geological and atmospheric circumstances [134]. Pollutants might be distributed in soil in several ways, namely [135]:  
* In soil matrix. * In vapour phase. * In non-aqueous phase. * In groundwater. Conventional agricultural methods of soil decontamination are based on chemical compounds, such as chlorine, and methyl and ethyl derivatives--trichloromethane, ethylene oxide, or methyl bromide. The latter, quite commonly applied to fungal and bactericidal decontamination, was banned from practical use (in developed countries since 2005, and in other countries, including Poland, since 2015). Many techniques of soil remediation, such as heating, flushing with chemical additives (surfactants), irradiation, irradiation with catalyst, soil vapour extraction, land filling, incineration [15; 105], aeration, oxidation, and bioremediation have been tested alone or in combination. Other methods, including autoclaving (moist heat), dry heat and microwave, have been attempted as alternatives to chemical fumig [83]. Soil treatment using pesticides is one of the effective ways to resist the spread of diseases in the soil. However, pesticide residues in the groundwater, caused by the overuse of chemicals, has become a serious issue in agriculture. From the environmental point of view, alternative methods of soil treatment are being sought. Oidation techniques involve ozone, hydrogen peroxide, chlorine dioxide, and potassium permanganate. Trials employing the usage of ozone, alone or combined with AOPs, have been performed in the treatment of soil by international research groups [18]. Ozone generated during electrical discharges, because of its relatively good solubility in the aqueous phase, seems to especially have potential for soil treatment, as it can be applied in both the gaseous and aqueous phases. Eco-oxidative techniques can improve soil aeration, thus inhibiting denitrification processes. Application of AOPs helps to preserve the natural structure of soil, preventing its acidification, leaching and the release of metallic compounds.