# Heat Capacity of Drained Peat Soils
## 4 Discussion  
This study indicates that the specific heat capacity (\(c_{p}\)) of the peat and peat-muck soils considered was linearly dependent on changes in their temperature in the range of \(-20\)\({}^{\circ}\)C to 30 \({}^{\circ}\)C, similar to findings for mineral soils [19]. This temperature range was chosen for \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Dependent** & \(n\) & **Predictors** &
\begin{tabular}{c} **Manuscript** \\ **Reference** \\ \end{tabular} & \(\mathbf{R^{2}}\) & \(\mathbf{R^{2}_{adj.}}\) & \(\mathbf{RMSE_{m}}\) & \(\mathbf{RMSE_{cv}}\) \\ \hline \multirow{3}{*}{\(C_{0}\)} & 1 & N & Figure 6a & 0.6003 & 0.5753 & 0.0524 & 0.0573 \\  & 2 & C:N,C:N2 & Figure 6b & 0.6133 & 0.5617 & 0.0515 & 0.0576 \\  & 3 & C, N, AC & Equation (5) & 0.7146 & 0.6535 & 0.0443 & 0.0554 \\ \hline \multirow{3}{*}{\(C_{1}\)} & 1 & N & Figure 6c & 0.7468 & 0.7310 & 0.000168 & 0.000188 \\  & 3 & AC, AC2, AC3 & Figure 6d & 0.8143 & 0.7745 & 0.000144 & 0.000195 \\ \cline{1-1}  & 2 & C:N, AC & Equation (6) & 0.8594 & 0.8407 & 0.000125 & 0.000153 \\ \cline{1-1}  & 3 & C:N, \(\rho_{\flat}\), \(P_{\circ}\) & Equation (7) & 0.8770 & 0.8506 & 0.000117 & 0.000151 \\ \hline \end{tabular}
\end{table} 
Table 3: Statistical measures in the \(c_{p}\)(\(T\)) relationship parameters prediction. the MDSC experiments because it was representative of the seasonal variation to which the soil is exposed under natural conditions [52]. In this study, regardless of the temperature, the lowest \(c_{p}\) values were observed in moss peaks characterized by very low soil ash content. The highest \(c_{p}\) values were observed in alder peaks. It should be emphasized that peat groups containing sedge species were characterized by similar \(c_{p}\) properties. The specific heat capacity of moorsh formations were positioned between alder and sedge-mos pests. Peat soils belong to the group of organic materials that are characterized by a high content of organic substances, i.e., wood and coal. Hence, one may expect these specific materials of biological origin to have similar thermal properties. Since studies on the specific heat of fuel materials (wood and coal) are well documented [53; 54; 55; 56; 57; 58; 59], these can be used for comparison. The linear relationship observed in this study was very similar to the general model of specific heat prediction of wood [53]. This similarity was particularly evident in the slope, \(C_{1}\), of the \(c_{p}\)(T) relation (Table 4), which was 0.0043 and 0.0046 J g\({}^{-1}\) K\({}^{-1}\) on average for organic soils and wood, respectively. However, the intercepts, \(C_{0}\), for organic soils (1.202 J g\({}^{-1}\) K\({}^{-1}\)) and wood (1.114 J g\({}^{-1}\) K\({}^{-1}\)) were different. Table 4 presents a summary of estimates of the specific heat parameters for selected organic origin materials. The calculations were made in reference to the research results published by [PERSON] and [PERSON] (2004) [20] for Pahosee peat and the \(c_{p}\) values for the temperatures of 0 \({}^{\circ}\)C and 25 \({}^{\circ}\)C. These compiled estimates show that high-calorie coal (Anthracite with residual ash equal to 4.7%) had the lowest specific heat characteristics. The estimated \(c_{p}\) value, regardless of temperature, increased with increasing residual ash content in the coal mass (Gliwice coal with ash content equal to 5.2%). The results of this study indicate a similar tendency for the organic soils considered. Besides, the specific heat capacity estimators of [PERSON] and [PERSON] (2004) [20] were close to those obtained for the moss peat (Table 4) with low nitrogen content and high organic carbon content. Specific heat capacity prediction model of hard coal is described by a complex regression equation considering, among others, carbon and nitrogen content [60]. Both components but also their ratio (C:N), which is an indicator of soil degradation [6], were also major predictors in modeling the \(C_{0}\) and \(C_{1}\) parameters in the \(c_{p}\)(T) relationships in the studied peat soils.