## 3 Results and Discussion
### Effect of Treated Sludge on Soil Fertility, and Chemical and Microbiological Properties
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline
**Treatment** & **Cu** & **Zn** & **Fe** & **Mn** & **Ni** & **Pb** & **B** \\ \hline \multicolumn{10}{c}{**mg kg\({}^{-1}\)**} \\ \hline \multicolumn{10}{c}{**Acid Soil**} \\ \hline AcB & 3.71 \(\pm\) 0.29 a & 5.35 \(\pm\) 0.24 b & 95.1 \(\pm\) 4.7 ab & 285.4 \(\pm\) 14.9 ab & 2.02 \(\pm\) 0.14 a & 4.42 \(\pm\) 0.55 ab & 0.57 \(\pm\) 0.03 c \\ AcV & 3.47 \(\pm\) 0.21 a & 5.07 \(\pm\) 0.64 b & 89.2 \(\pm\) 2.8 bc & 282.5 \(\pm\) 17.3 b & 1.99 \(\pm\) 0.09 a & 4.41 \(\pm\) 0.74 ab & 0.58 \(\pm\) 0.05 c \\ AcBc & 3.43 \(\pm\) 0.18 ab & 5.06 \(\pm\) 0.31 b & 87.8 \(\pm\) 3.3 c & 284.4 \(\pm\) 18.6 ab & 1.94 \(\pm\) 0.16 b & 3.84 \(\pm\) 0.30 bc & 0.65 \(\pm\) 0.03 b \\ AcL & 3.45 \(\pm\) 0.07 a & 4.79 \(\pm\) 0.24 b & 46.2 \(\pm\) 2.4 e & 76.2 \(\pm\) 5.0 d & 1.06 \(\pm\) 0.04 c & 2.09 \(\pm\) 0.18 d & 0.27 \(\pm\) 0.04 d \\ AcD & 3.44 \(\pm\) 0.20 a & 7.65 \(\pm\) 1.14 a & 81.6 \(\pm\) 4.3 d & 245.6 \(\pm\) 8.3 a & 1.75 \(\pm\) 0.12 b & 3.46 \(\pm\) 0.19 b & 0.80 \(\pm\) 0.07 a \\ AcIF & 2.92 \(\pm\) 0.11 c & 1.46 \(\pm\) 0.68 c & 97.0 \(\pm\) 2.6 a & 282.8 \(\pm\) 14.7 b & 2.01 \(\pm\) 0.06 a & 4.58 \(\pm\) 0.10 a & 0.24 \(\pm\) 0.03 d \\ AcIFX & 2.99 \(\pm\) 0.09 c & 0.93 \(\pm\) 0.03 c & 99.7 \(\pm\) 3.6 a & 308.0 \(\pm\) 11.9 a & 2.04 \(\pm\) 0.03 a & 4.71 \(\pm\) 0.20 a & 0.28 \(\pm\) 0.00 d \\ AcC & 3.08 \(\pm\) 0.35 bc & 0.80 \(\pm\) 0.07 c & 98.0 \(\pm\) 3.1 a & 296.9 \(\pm\) 16.1 ab & 2.04 \(\pm\) 0.18 a & 4.76 \(\pm\) 0.17 a & 0.26 \(\pm\) 0.03 d \\ \hline \multicolumn{10}{c}{**Alkaline Soil**} \\ \hline AlB & 3.68 \(\pm\) 0.14 a & 4.38 \(\pm\) 0.40 b & 24.5 \(\pm\) 1.1 a & 29.7 \(\pm\) 1.3 b & 2.59 \(\pm\) 0.11 bc & 1.11 \(\pm\) 0.02 bc & 0.75 \(\pm\) 0.03 b \\ AlV & 3.87 \(\pm\) 0.41 a & 4.24 \(\pm\) 0.64 b & 22.8 \(\pm\) 1.5 a & 25.7 \(\pm\) 3.4 b & 2.26 \(\pm\) 0.16 d & 1.12 \(\pm\) 0.07 bc & 0.89 \(\pm\) 0.06 a \\ AlBc & 3.03 \(\pm\) 0.33 c & 4.20 \(\pm\) 1.25 b & 22.1 \(\pm\) 2.8 a & 25.4 \(\pm\) 5.7 b & 2.24 \(\pm\) 0.23 d & 1.04 \(\pm\) 0.10 c & 0.90 \(\pm\) 0.03 a \\ AIL & 3.24 \(\pm\) 0.10 bc & 3.76 \(\pm\) 0.25 b & 26.3 \(\pm\) 2.6 a & 40.9 \(\pm\) 2.1 a & 2.97 \(\pm\) 0.12 a & 1.07 \(\pm\) 0.16 bc & 0.74 \(\pm\) 0.08 b \\ AID & 3.56 \(\pm\) 0.21 ab & 6.36 \(\pm\) 1.52 a & 23.2 \(\pm\) 0.5 a & 26.2 \(\pm\) 1.0 b & 2.42 \(\pm\) 0.05 cd & 1.32 \(\pm\) 0.09 a & 0.93 \(\pm\) 0.08 a \\ AIIF & 2.57 \(\pm\) 0.09 d & 1.00 \(\pm\) 0.08 c & 23.0 \(\pm\) 0.5 a & 42.1 \(\pm\) 1.2 a & 2.76 \(\pm\) 0.04 ab & 1.15 \(\pm\) 0.04 bc & 0.67 \(\pm\) 0.02 bc \\ AIIFX & 2.50 \(\pm\) 0.14 d & 0.83 \(\pm\) 0.01 c & 23.2 \(\pm\) 0.7 a & 41.1 \(\pm\) 1.9 a & 2.55 \(\pm\) 0.08 bc & 1.09 \(\pm\) 0.06 bc & 0.71 \(\pm\) 0.00 b \\ AIC & 2.60 \(\pm\) 0.09 d & 0.86 \(\pm\) 0.05 c & 22.1 \(\pm\) 0.8 a & 28.6 \(\pm\) 1.0 b & 2.26 \(\pm\) 0.17 d & 1.19 \(\pm\) 0.05 ab & 0.58 \(\pm\) 0.07 c \\ \hline \multicolumn{10}{c}{**\(p\) F-test**} \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Concentrations of available micronutrients and heavy metals of soil treatments before the pot experiment with white clover. Available Cr, Cd and Hg were not detectable. NS: non-significant. Treatment of the acid and alkaline soil, respectively, with: AcB and AIB: bentonite-treated sludge; AcV and AIV: vermiculite-treated sludge; AcB and AlBc: biochar-treated sludge; AcL and AIL: timed sludge; AcD and AlD: air-dried sludge; AcIF and AIIF: N-P-K inorganic fertilization; AcIFX and AlIFX: P-K inorganic fertilization; AcC and AIC: control. Different letters, within each soil and property, indicate significant differences among means, using the LSD test, at \(p\leq\) 0.05.  
with lined sludge (All) (12.5 mg g\({}^{-1}\)) before the pot experiment and in the treatment with vermiculite-treated sludge (AIV) (24.2 mg g\({}^{-1}\)) after the pot experiment, compared to the control of each case (7.4 mg g\({}^{-1}\) and 12.2 mg g\({}^{-1}\), respectively). That occurred probably because the particular treatments had the highest available N content for the respective periods.