## 3 Results and Discussion
### Bio-Mixture Effect on pH, EC, Organic Matter, CEC and ESP of Soil  
The texture of the control soil (C) was loam and remained the same in each treatment (biomix 1%, biomix 2%, biomix 3%) (Tables 4 and 5), indicating that the effect of adding the bio-mixture at these rates on soil texture is negligible.  
The pH, electrical conductivity (EC), organic matter (OM), cation exchange capacity (CEC) and exchange sodium percentage (ESP) variations between the treatments are presented in Tables 4 and 5.  
The results showed that at 0-20 cm depth, pH increased the same in the three bio-mixtures treatments, from 7.01 (control) to 7.15, with the differences between the control soil and the bio-mixtures being significant (\(p<0.05\)), while at 20-40 cm depth there were found no significant differences between the treatments. EC was slightly affected by the application of the bio-mixture, showing small increases of 6%, 3% and 8% for 1% biomix, 2% biomix and 3% biomix, respectively (Tables 4 and 5). However, in most cases there were found no significant differences between the treatments, while values remained below the salinity threshold [11].  
Regarding organic matter (O.M.), a significant (\(p<0.05\)) gradual increase was observed as the percentage of the bio-mixture increased. More specifically, organic matter of samples from 0-20 cm depth, increased from 3.41% to 3.85%, 4.07% and 4.04% for 1% biomix, 2% biomix and 3% biomix, respectively. It is noteworthy that at 20-40 cm depth, no significant differences were observed between the treatments, since the movement of large organic molecules through the soil layer is difficult [33].  
Similarly, cation exchange capacity (CEC) increased at surface soil (0-20 cm) from 17.8 cmol\({}_{\text{c}}\) kg\({}^{-1}\) (control soil) to 18.1, 19.1 and 20.3 cmol\({}_{\text{c}}\) kg\({}^{-1}\) for 1% biomix, 2% biomix and 3% biomix, respectively (Tables 4 and 5). The suchlike increase occurred in the soil samples at the 20-40 cm depth (Tables 4 and 5), pointing out the significant contribution of organic matter to this parameter. In both depths, the highest values were recorded in biomix 3% treatment, and their differences with control soil and biomix 1% were significant (\(p<0.05\)).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \
\begin{tabular}{c} **Sample** \\ **(0–20 cm Depth)** \\ \end{tabular} & **Sand (\%)** & **Silt (\%)** & **Clay (\%)** & **pH** & **EC (\#S cm\({}^{-1}\))** & **O.M. (\%)** &
\begin{tabular}{c} **CEC** \\ **(cmol\({}_{\text{c}}\) kg\({}^{-1}\))** \\ \end{tabular} & **ESP (\%)** \\ \hline C & 46.4 & 27.5 & 26.1 & 7.01 b & 351 ab & 3.41 c & 17.8 b & 1.25 a \\ Biomix 1\% & 46.1 & 28.4 & 25.5 & 7.15 a & 371 a & 3.85 b & 18.1 b & 1.19 a \\ Biomix 2\% & 46.0 & 27.2 & 26.8 & 7.15 a & 340 b & 4.07 a & 19.1 ab & 1.15 a \\ Biomix 3\% & 45.2 & 27.7 & 27.1 & 7.15 a & 378 a & 4.04 a & 20.3 a & 1.08 a \\ \hline \hline \end{tabular}
\end{table}
Table 4: Soil texture, pH, EC, O.M., CEC and ESP in the four treatments at 0–20 cm depth \({}^{\text{z}}\).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \
\begin{tabular}{c} **Sample** \\ **(20–40 cm Depth)** \\ \end{tabular} & **Sand (\%)** & **Silt (\%)** & **Clay (\%)** & **pH** & **EC (\#S cm\({}^{-1}\))** & **O.M. (\%)** &
\begin{tabular}{c} **CEC** \\ **(cmol\({}_{\text{c}}\) kg\({}^{-1}\))** \\ \end{tabular} & **ESP (\%)** \\ \hline C & 45.7 & 28.8 & 25.5 & 6.94 a & 358 a & 3.45 a & 18.4 b & 1.22 a \\ Biomix 1\% & 44.7 & 28.5 & 26.8 & 7.02 a & 364 a & 3.89 a & 18.5 b & 1.20 a \\ Biomix 2\% & 46.5 & 27.3 & 26.1 & 6.98 a & 364 a & 3.95 a & 19.1 ab & 1.15 a \\ Biomix 3\% & 45.1 & 27.7 & 27.2 & 7.02 a & 369 a & 3.95 a & 20.3 a & 1.14 a \\ \hline \hline \end{tabular}
\end{table}
Table 5: Soil texture, pH, EC, O.M., CEC and ESP in the four treatments at 20–40 cm depth \({}^{\text{z}}\).  
In the case of ESP, no significant differences were found between the treatments in either depth.