# Popular Biochar as an Alternative Substrate for Curly Endive Cultivated in a Soilless System
## 3 Results
### Nutritional and Functional Properties  
Combining biochar at 70% and pyrolysis temperature at 450 \({}^{\circ}\)C resulted in the highest SSC. The lowest SSC were recorded from plants cultivated in the growing substrate with biochar at 100% and a pyrolysis temperature of 700 \({}^{\circ}\)C (Table 4). Overall, SSC decreased with the increase of the pyrolysis temperature. ANOVA for TA did not show a significant effect of the treatments (Table 4). Data collected on ascorbic acid supported the trend established for the SSC (Table 4). Curly entive plants cultivated on biochar at 70% with a pyrolysis temperature of 450 \({}^{\circ}\)C and on biochar at 100% with a pyrolysis temperature of 450 \({}^{\circ}\)C had the highest total phenolic content (Table 4), followed by those grown on biochar at 70% with a pyrolysis temperature of 700 \({}^{\circ}\)C and biochar at 100% with a pyrolysis temperature of 700 \({}^{\circ}\)C. The lowest total phenolic content was recorded from plants cultivated on biochar at 20% with a pyrolysis temperature of 700 \({}^{\circ}\)C. However, plants grown on peat at 100% did not significantly differ from plants grown on biochar at 20% with a pyrolysis temperature of 450 \({}^{\circ}\)C and from those grown on biochar 20% with a pyrolysis temperature of 700 \({}^{\circ}\)C.  
Data on plant minerals content are presented in Table 5. ANOVA for P and Mg content did not reveal a significant effect of the treatments. Curly entive plants grown on 100% peat had the highest leaves N content, followed by those cultivated on a substrate mixture with 20% biochar produced via a pyrolysis temperature of 450 \({}^{\circ}\)C, \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Treatments** & **SSC (\({}^{\circ}\)Brix)** & **TA (\%)** & \
\begin{tabular}{c} **Ascorbic Acid** \\ **(mg kg\({}^{-1}\) f.w.)** \\ \end{tabular} &
\begin{tabular}{c} **Total Phenolic (mg of** \\ **Caffeic Acid g\({}^{-1}\) f.w.)** \\ \end{tabular} \\ \hline Peat & \(4.3\pm 0.1\) & cd & \(0.7\pm 0.1\) & a & \(69.5\pm 3.3\) & e & \(0.57\pm 0.04\) & ef \\ Biochar 20\%\_450 & \(4.4\pm 0.1\) & bc & \(0.6\pm 0.2\) & a & \(83.3\pm 2.7\) & d & \(0.64\pm 0.02\) & de \\ Biochar 20\%\_700 & \(4.2\pm 0.1\) & d & \(0.6\pm 0.1\) & a & \(81.7\pm 2.9\) & d & \(0.53\pm 0.01\) & f \\ Biochar 40\%\_450 & \(4.6\pm 0.1\) & b & \(0.6\pm 0.1\) & a & \(90.6\pm 1.5\) & bc & \(0.76\pm 0.02\) & bc \\ Biochar 40\%\_700 & \(4.3\pm 0.1\) & cd & \(0.6\pm 0.1\) & a & \(859\pm 1.5\) & cd & \(0.67\pm 0.03\) & cd \\ Biochar 70\%\_450 & \(4.8\pm 0.1\) & a & \(0.7\pm 0.1\) & a & \(103.2\pm 2.1\) & a & \(0.92\pm 0.03\) & a \\ Biochar 70\%\_700 & \(4.6\pm 0.1\) & b & \(0.7\pm 0.2\) & a & \(96.1\pm 0.9\) & b & \(0.88\pm 0.04\) & b \\ Biochar 100\%\_450 & \(4.3\pm 0.1\) & cd & \(0.7\pm 0.1\) & a & \(87.1\pm 2.7\) & cd & \(0.95\pm 0.04\) & a \\ Biochar 100\%\_700 & \(4.2\pm 0.1\) & d & \(0.7\pm 0.1\) & a & \(82.0\pm 2.3\) & d & \(0.81\pm 0.02\) & b \\ \hline Significance & *** & \multicolumn{3}{c}{NS} & *** & *** \\ \hline \multicolumn{7}{l}{The same letter within a column identifies data (mean \(\pm\) standard deviation) not significantly different (\(p\leq 0.05\) Tukey HSD Test). Asterisks (***) are designated for the significance (\(p\)-value \(\leq 0.001\)).} \\ \end{tabular}
\end{table} 
Table 4: Analysis of variance and means comparisons for SSC, TA, ascorbic acid and total phenolic of curly entive cultivated on different growing substrates in a protected environment.