# Optimization of Blended Biochar Pellet by the Use of Nutrient Releasing Model
## 3 Results
The highest accumulated amount of K in the PMCP was 1917 mg L\({}^{-1}\) and the lowest in the BCP (9:1) was 1078 mg L\({}^{-1}\). It appeared that accumulated amounts of K abruptly increased at the early leaching stage, and gradually increased at later stages (Figure 4). Figure 3: Effects of accumulated PO\({}_{4}\)-P concentrations in the releasing water from biochar pellet blended with various ratio of pig manure compost. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Treatments**} & \multicolumn{3}{c}{**Model Parameters**} & \multicolumn{3}{c}{**Analysis of Variance**} \\ \cline{2-7}  & **A\({}_{\text{max}}\)** & _p-Values_ & **t\({}_{\text{1/2(Amax)}}\)** & _p-Values_ & **F** & _p-Values_ & **\(R^{2}\)** \\ \hline PMC & 1966.4 & \textless{}0.0001 & 7.6 & 0.0003 & 378.8 & \textless{}0.0001 & 0.88 \\ PMCP & 1108.3 & \textless{}0.0001 & 20.9 & \textless{}0.0001 & 686.4 & \textless{}0.0001 & 0.93 \\ BCP (9:1) & 208.8 & \textless{}0.0001 & 1.4 & \textless{}0.0001 & 122.3 & \textless{}0.0001 & 0.70 \\ BCP (8:2) & 422.3 & \textless{}0.0001 & 3.3 & \textless{}0.0001 & 200.2 & \textless{}0.0001 & 0.79 \\ BCP (4:6) & 908.5 & \textless{}0.0001 & 21.2 & \textless{}0.0001 & 1092.1 & \textless{}0.0001 & 0.95 \\ BCP (2:8) & 1050.3 & \textless{}0.0001 & 24.5 & \textless{}0.0001 & 1002.5 & \textless{}0.0001 & 0.95 \\ \hline \hline \end{tabular} PMC; control as pig manure compost, PMCP; pig manure compost pellet, and BCP; ratios of biochar pellets blended of biochar/pig manure compost 2:8, 4:6, 8:2, and 9:1.  
\end{table} 
Table 3: Estimation model for accumulated PO\({}_{4}\)-P releasing amount from different types of biochar pellets. The estimation model for K accumulated amount from different types of biochar pellets is presented in Table 4. The estimation values calculated from the modified equation were significantly correlated with the observed values for K releasing, regardless of combinations of biochar pellets. Most of K was released within 2 days of leaching periods. The estimated releasing model for the modified equation significantly fits with all the treatments (Table 4). It has appeared that the highest accumulated amount of SiO\({}_{2}\) in the PMCP was 1259 mg L\({}^{-1}\), but the lowest in the PMC was 634 mg L\({}^{-1}\) at 20 days of leaching periods (Figure 5). Following this, it then decreased after that period even if it did not contain biochar from rice hull. The estimation model for accumulated SiO\({}_{2}\) releasing amount from different BCP is presented in Table 5. The estimation values calculated from a modified equation were significantly correlated with the observed values for accumulated SiO\({}_{2}\) releasing amount regardless of combination rates of biochar pellets. The estimated releasing model equation was had a highly significant fit with whole treatments (Table 5). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Treatments**} & \multicolumn{4}{c}{**Model Parameters**} & \multicolumn{4}{c}{**Analysis of Variance**} & \multirow{2}{*}{\(\mathbf{R^{2}}\)} \\ \cline{2-2} \cline{5-8}  & \(\mathbf{A_{max}}\) & \(\mathbf{p}\)-Values & \(\mathbf{t_{1/2(A_{max})}}\) & \(\mathbf{p}\)-Values & \multicolumn{1}{c}{F} & \(\mathbf{p}\)-Values \\ \hline PMC & 1456.1 & \textless{}0.0001 & 0.8 & 0.0003 & 94.2 & \textless{}0.0001 & 0.76 \\ PMCP & 1864.5 & \textless{}0.0001 & 0.7 & \textless{}0.0001 & 257.5 & \textless{}0.0001 & 0.90 \\ BCP (9:1) & 1056.8 & \textless{}0.0001 & 0.6 & \textless{}0.0001 & 299.5 & \textless{}0.0001 & 0.91 \\ BCP (8:2) & 1182.4 & \textless{}0.0001 & 0.6 & \textless{}0.0001 & 259.6 & \textless{}0.0001 & 0.90 \\ BCP (4:6) & 1789.9 & \textless{}0.0001 & 1.6 & \textless{}0.0001 & 346.3 & \textless{}0.0001 & 0.92 \\ BCP (2:8) & 1649.6 & \textless{}0.0001 & 1.5 & \textless{}0.0001 & 302.0 & \textless{}0.0001 & 0.91 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Estimation model for accumulated K releasing amount from different types of biochar pellets.