## 2 Materials and Methods
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameter** & **Symbol** & **Unit** & **Range** & **Result** \\ \hline Reaction & pH & 1–14 & 6.0–8.5 & 7 \\ Sodium adsorption ratio & SAR & me/L & 0–15 & 11 \\ Electrical conductivity & ECw & dS/m & 0–3 & 0.97 \\ \hline Nitrogen & Nitrate & NO\({}_{3}\)-N & mg/L & 0–10 & 0.68 \\ Nitrite & Nitrile & NO\({}_{2}\)-N & mg/L & 0–10 & 0.0012 \\ Ammonium & NH\({}_{4}\)-N & mg/L & 0–5 & 0.429 \\ Phosphate & & PO\({}_{4}\)-P & mg/L & 0–2 & 0.865 \\ \hline Sulfate & & SO\({}_{4}\)-S & me/L & 0–20 & 1.898 \\ Chloride & & Cl\({}^{-}\) & me/L & 0–30 & 0.449 \\ Calcium & & Ca\({}^{2+}\) & me/L & 0–20 & 3.444 \\ Magnesium & & Mg\({}^{2+}\) & me/L & 0–5 & 5.076 \\ Sodium & & Na & me/L & 0–40 & 0.718 \\ \hline Iron & & Fe & mg/L & 0–5 & 0.12 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Irrigation water quality. Figure 1: Experimental plot design. The calibration results are presented in Table 3. The correlation analysis showed a strong negative relationship between the SWC and GMS readings. Furthermore, according to the calibration results, the 0-40 cbar GMS range denotes 100% of the FC, while 70-80 cbar denotes the management allowable depletion (MAD). This means that the irrigation time was complete when the GMS readings were 70-80 cbar (60% of FC) for the a2 treatment and 40 cbar (80% of FC) for the a3 treatment. The sensor calibration curve was previously presented by [PERSON] et al. [29]. The SWC was approximately measured three times per week after irrigation events or a significant amount of rainfall (\(>\)5 mm). The irrigation rate on both irrigation treatments was 35 mm, which was calculated using the following model:  
\[\text{IR}=100\times\text{Bd}\times\text{h}\times(\text{FC}-\text{RAW}), \tag{1}\]  
where IR is the amount of added water in one irrigation event (mm or L m\({}^{2}\)), Bd is the bulk density (g cm\({}^{-3}\)), h is the depth of irrigation water penetration (m), FC is the field capacity (%), and RAW denotes the readily available water (as a percentage of FC). The efficiency of irrigation was tested according to [PERSON] et al. [63]:  
\[\text{IWUE}=(\text{Yi}-\text{Yr})/\text{NIR}, \tag{2}\]  
where IWUE stands for the irrigation water use efficiency (kg ha\({}^{-1}\) mm\({}^{-1}\)), Yi stands for the GY on irrigated plot (kg), Yr stands for the GY on a rainfed plot (kg), while NIR stands for the net irrigation rate (mm). The amount and form of N fertilizers applied for each fertilizer treatment during the study period are presented in Table 4. Basic/autumn and basal application, i.e., pre-sowing (April month) maize fertilization, was done with urea. Two side dressings were performed for the b2 and b3 N fertilizer treatments with the use of calcium ammonium nitrate (CAN) spread by hand around the plants and in between the plant rows. Side dressing fertilizer applications were done during the May/June period. The efficiency of the N fertilizer rate was tested according to [PERSON] et al. [64]:  
\[\text{FUE}=(\text{Yf}-\text{Yc})/\text{FR}, \tag{3}\]  
where FUE stands for the fertilizer use efficiency, Yf stands for the GY (kg) from the fertilized treatment, Yc stands for the GY (kg) from the control (unfertilized) treatment, and FR stands for the N fertilizer rate (kg). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Fertilization** & **b1 (0 kg N ha\({}^{-1}\))** & **b2 (100 kg N ha\({}^{-1}\))** & **b3 (200 kg N ha\({}^{-1}\))** & **Fertilizer** \\ \hline Basic/autumn & 0 & 33.5 & 66.5 & Urea (46\% N) \\ Pre-sowing & 0 & 33.5 & 66.5 & Urea (46\% N) \\
1 st side dressing & 0 & 16.5 & 32.5 & CAN (27\% N) \\
2 nd side dressing & 0 & 16.5 & 32.5 & CAN (27\% N) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Amount and form of N fertilizers.