## 1 Introduction
The reactive species in PAW have antimicrobial properties, which help activate plant defense mechanisms and increase resistance to environmental stressors such as drought, salinity, and extreme temperatures [32; 33; 34; 35]. Beyond its agricultural benefits, PAW has been demonstrated to extend the shelf life of food products, inhibit microbial growth, and improve food safety and quality during food processing [32; 33; 34; 35]. The production of conventional nitrogen fertilizers, like urea, is highly energy-intensive and contributes significantly to carbon dioxide emissions [36; 37; 38; 39]. PAW technology offers a potential reduction in energy consumption of up to 68% compared to traditional urea synthesis. Unlike conventional methods, PAW production does not emit greenhouse gases, making it a highly sustainable alternative for nitrate fertilizer production [39]. By infusing water with RNS through plasma treatment, PAW generates a nitrate-rich solution that can be applied directly to crops, promoting efficient nutrient uptake and reducing dependency on chemical fertilizers. Moreover, PAW exhibits high stability, with nitrogen compounds remaining active for up to four weeks without degradation, making it a reliable solution for sustained nutrient supply [40; 41; 42; 43]. The reactive species generated during plasma treatment include singlet oxygen, superoxides, electrons, ozone, and ultraviolet radiation [39; 44]. These species initiate a series of complex chemical reactions within the liquid, producing key reactive intermediates that contribute to nutrient enrichment. Analytical techniques such as electron paramagnetic resonance (EPR), UV-visible spectrophotometry, and liquid chromatography are commonly used to identify and quantify these reactive species in plasma-treated liquids. Additionally, techniques like gas sensors, Fourier-transform infrared (FTIR) spectroscopy, laser-induced fluorescence (LIF), and mass spectrometry are utilized to detect gaseous products generated during the plasma-water interaction [45; 46]. The production of Plasma-Activated Water (PAW) involves several critical processes at the liquid-gas interface. Reactive species generated in the plasma discharge transfer into the liquid phase, where they induce dynamic chemical reactions with water molecules [47]. These reactions result in the formation of highly reactive short-lived species, such as hydroxide ions (OH\(-\)) and hydrated electrons (e\(-\) solv). These unstable species rapidly transform into more stable compounds like superoxides (O\({}_{2}-\)), ozone (O\({}_{3}\)), and hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)), all of which play crucial roles in nitrate production [48]. The non-equilibrium conditions created by the plasma lead to efficient energy transfer and enhanced fertilizer production. Compared to traditional methods, PAW technology offers substantial energy savings and environmental advantages. The nitrate solution produced through PAW can be formulated into liquid or granular fertilizers, depending on the application. In addition, its high stability ensures that nitrogen compounds remain effective over extended periods, supporting nutrient availability throughout the crop cycle [40; 41; 42; 43]. Furthermore, PAW technology enhances seed germination rates, plant growth, and nutrient uptake without compromising yield quality. This makes PAW a highly efficient and environmentally sustainable solution applicable across a wide range of agricultural practices, including both hydroponic and soil-based farming systems [49]. This study investigates the application of Plasma-Activated Water (PAW) technology in producing nitrate fertilizer. By analyzing the dielectric properties of plasma-treated water, the research aims to optimize the efficiency of nitrate production through improved plasma exposure times and water flow rates. These insights will help develop more sustainable, efficient nitrate fertilizers that support environmentally friendly agricultural practices.