## 3 Results
### Experiment Termination
#### 3.2.4 Soil Lead
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Soil Parameter Correlate** & \multicolumn{3}{c}{**BIOC**} & \multicolumn{3}{c}{**COMP**} & \multicolumn{3}{c}{**INF**} & \multicolumn{3}{c}{**UNAM**} \\ \hline  & \(p\)**-Value** & **Corr Coeff** & \(p\)**-Value** & **Corr Coeff** & \(p\)**-Value** & **Corr Coeff** & \(p\)**-Value** & **Corr Coeff** \\ \hline
**All** & \multicolumn{3}{c}{_(\(n=17\))_} & \multicolumn{3}{c}{_(\(n=17\))_} & \multicolumn{3}{c}{_(\(n=14\))_} & \multicolumn{3}{c}{_(\(n=8\))_} \\ EC (\(\mu\)s cm\({}^{-1}\)) & \(\leq\)0.05 & 0.57 & - & - & \(\leq\)0.05 & \(-\)0.62 & - & - \\ PMN (mg kg\({}^{-1}\)) & \(\leq\)0.01 & \(-\)0.67 & - & - & \(\leq\)0.05 & 0.61 & \(\leq\)0.10 & 0.48 \\ INN (mg kg\({}^{-1}\)) & \(\leq\)0.05 & 0.52 & - & - & \(\leq\)0.001 & \(-\)0.85 & - & - \\ DOC (mg kg\({}^{-1}\)) & \(\leq\)0.05 & 0.51 & - & - & - & - & - & - \\ DON (mg kg\({}^{-1}\)) & \(\leq\)0.01 & 0.69 & - & - & \(\leq\)0.01 & \(-\)0.68 & - & - \\ AP (mg kg\({}^{-1}\)) & - & - & - & - & - & \(\leq\)0.001 & 0.78 \\ CN Radio & - & - & - & - & - & - & \(\leq\)0.05 & \(-\)0.52 \\ Available Fe (mg kg\({}^{-1}\)) & \(\leq\)0.001 & 0.90 & - & - & \(\leq\)0.01 & 0.72 & - & - \\
**Radish** & \multicolumn{3}{c}{_(\(n=8\))_} & \multicolumn{3}{c}{_(\(n=8\))_} & \multicolumn{3}{c}{_(\(n=8\))_} & \multicolumn{3}{c}{_(\(n=8\))_} \\ DOC (mg kg\({}^{-1}\)) & \(\leq\)0.05 & \(-\)0.77 & - & - & - & - & - & - \\ TOC (mg kg\({}^{-1}\)) & \(\leq\)0.01 & 0.94 & \(\leq\)0.01 & 0.84 & - & - & - & - \\ CN Radio & \(\leq\)0.05 & 0.83 & - & \(\leq\)0.001 & \(-\)0.94 & - & - & - & - \\ pH (12, soil:H\({}_{2}\)0) & - & - & \(\leq\)0.001 & \(-\)0.94 & - & - & - & - \\ DON (mg kg\({}^{-1}\)) & \(\leq\)0.05 & \(-\)0.72 & - & - & - & - & - & - \\ Available Fe (mg kg\({}^{-1}\)) & \(\leq\)0.01 & 0.88 & - & - & - & - & - & - \\
**Lettuce** & \multicolumn{3}{c}{_(\(n=6\))_} & \multicolumn{3}{c}{_(\(n=6\))_} & \multicolumn{3}{c}{_(\(n=3\))_} & \multicolumn{3}{c}{_(\(n=5\))_} \\ Available Fe (mg kg\({}^{-1}\)) & \(\leq\)0.01 & 0.93 & - & - & - & - & - & - \\ \hline \hline \end{tabular}
\end{table} 
Table 6: \(p\)-Values and significant values of correlation coefficients representing relationships between soil available lead (Pb) and pH, electrical conductivity (EC), potentially mineralizable N (PMN), inorganic N (ammonium and nitrate, INN), dissolved organic nitrogen (DON), dissolved organic carbon (DOC), available phosphorous (AP), C:N ratio, and available iron (Fe) for both plant species, plus lab incubated soil (All) or Radish and Lettuce separately in soils amended with biochar, BIOC; compost, COMP, inorganic fertilizer, INF, and unamended control, UNAM. Statistical analysis was conducted using [PERSON]’s correlation test and observations were considered significant at \(p\leq 0.05\) and analyses were performed on number of observations as indicated in brackets below the column headings. Figure 4: Correlation between soil pH and available soil lead (Pb) among radish (R) and lettuce (L) samples. Colors represent different treatments (biochar, BIOC; compost, COMP, inorganic fertilizer, INF; and unamended control, UNAM) and shapes represent different life forms (diamond for lettuce and circle for radish). Statistical analysis was conducted using [PERSON]’s correlation test and observations were considered significant at \(p\leq 0.05\). Figure 5: Relationship between soil available iron (Fe) and available lead (Pb) using data from both plant species and lab incubation at the end of the experiment. Colors represent different treatments (biochar, BIOC; compost, COMP, inorganic fertilizer, INF, and unamended control, UNAM). A regression line accompanied by the slope equation and an R-sq value is shown (INF and BIOC only) when significant. Figure 6: Relationship between soil available lead (Pb) and soil nitrogen parameters: (**a**) dissolved organic nitrogen (DON); (**b**), potentially mineralizable N (PMN); and (**c**) and inorganic N (ammonium and nitrate).