# Applications of Plasma Produced with Electrical Discharges in Gases for Agriculture and Biomedicine
## 2 Plasma as a Medium for Application in Agriculture and Biomedicine
### Agricultural and Soil Protection Problems  
It is obvious that soil quality is a crucial factor for the prosperity and future of a region. Agriculture and soil protection include problems related to the overuse of chemicals to fertilise soil, which causes soil degradation; increases pesticide residues in soil, groundwater and food; and affects plant cultivation, seed quality and their germination capacity. An equally important problem is preventing the microbial contamination of soil and agricultural products, the latter during the processes of their processing, transport, and storage. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Plasma Properties** & **Thermal Plasma** & **Non-Thermal Plasma** \\ \hline State & Thermodynamic equilibrium & Kinetic equilibrium \\ \hline Electron density, \(1/\text{m}^{3}\) & \(10^{21}<n_{\text{e}}<10^{23}\) & \(10^{20}<n_{\text{e}}<10^{21}\) \\ \hline Pressure, Pa & \(10^{5}<p<10^{7}\) & \(10^{-1}<p<10^{5}\) \\ \hline Electron temperature, eV & \(1<T_{\text{e}}<10\) & \(0.2<T_{\text{e}}<2\) \\ \hline Gas temperature, eV & \(T_{\text{g}}=T_{\text{e}}\) & \(0.025<T_{\text{g}}<0.5\) \\ \hline Current, A & \(50<I<10^{4}\) & \(0.01<I<50\) \\ \hline Ionisation & Saha & uncertain \\ \hline \hline \end{tabular}  
* Elaborated on the basis of [9].  
\end{table} 
Table 1: Comparison of thermal and non-thermal plasma properties *. Figure 1: The technological complexity of plasma applications in agriculture and biomedicine. Recently, due to the growing emission of greenhouse gases into the atmosphere, and the related global warming of our planet, a significant increase in various ecological phenomena have been observed: droughts, floods, storms, and other disasters in areas where they have not previously been observed, leading to environment pollution. Apart from the direct destruction of crops, housing, and public facilities they inflict, floods are the cause of the massive contamination of soil and, thus, deterioration in soil quality. When a flood occurs, persistent odour and the contamination of buildings, such as farms, housing, and public institutions, are unavoidable. During restoration after a flood event, the most difficult challenges are related to:  
* Epidemiological risk and lack of drinking water due to polluted wells and destruction of water treatment plants. * Lack of simple, sufficient, and cheap drying and decontamination techniques for indoors. * Severe deterioration of indoor air quality due to the pollution of housing by flood water. Because of inadequate drying and disinfection techniques, infestation by very persistent mould often takes place. A secondary consequence is the rotting odour. * The presence of difficult-to-decompose sediments transported by flood waters, and chemical and biological pollution (bactericidal risk, secondary infestation by pests). * Surface water contamination. Furthermore, sapropelic sediments may contribute to secondary oxygen deficiency. * Risk of bactericidal and chemical soil and crop contamination. Some crops (depending on the flood season and growth phase) could possibly survive, but the dilemma remains whether they can be collected without risk. All these make it necessary to search for new techniques to solve problems related to the pollution of the agricultural environment, in particular soils and surface water. Application of ozone produced by electrical discharges in agriculture has, therefore, become one of the most important techniques to ensure the safety of plant growing, and soil and food treatment. The objective of agricultural soil sterilisation is to destroy or eliminate microbial cells and insects in the soil, but only those that cause decreasing soil fertility and destroy the seeds, roots and leaves of the plants. Conventional agricultural soil treatment methods based on chemical compounds, especially methyl bromide (CH3 Br),