## 3 Results and Discussion
### Soil
#### 3.1.2 Chemical Properties
ANOVA also revealed highly significantly differences between depths (F value = 117.07 and \(p\)-value < 0.001), with the highest mean values at the soil surface (110 mg kg\({}^{-1}\) at the 0-5 cm depth) and the lowest \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Soil Properties** & **Organic Carbon** & \multicolumn{2}{c}{**Potassium**} & \multicolumn{2}{c}{**Phosphorus**} & \multicolumn{2}{c}{**CEC**} \\ \hline
**Source of Variation** & **F Value** & **\(p\)-Value** & **F Value** & **\(p\)-Value** & **F Value** & **\(p\)-Value** & **F Value** & **\(p\)-Value** \\ \hline
**Tillage (T)** & 143.06 & 0.007 ** & 11.66 & 0.076 ns & 12.57 & 0.071 ns & 74.23 & 0.013 \({}^{*}\) \\
**Depth (D)** & 71.42 & \textless{}0.001 *** & 117.07 & \textless{}0.001 *** & 536.17 & \textless{}0.001 *** & 51.55 & \textless{}0.001 *** \\
**T \(\times\) D** & 2.36 & 0.060 ns & 7.23 & \textless{}0.001 *** & 48.87 & \textless{}0.001 *** & 2.42 & 0.056 ns \\ \hline \hline \end{tabular}  
* ns: not significant; \({}^{*}\), \({}^{**}\), and \({}^{***}\): significant at the 0.05, 0.01, and 0.001 levels, respectively.  
\end{table} 
Table 4: ANOVA results for soil properties measured before the start of the experiment. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Depth (cm)** & **Tillage** & **OC (g kg\({}^{-1}\))** & **Potassium (mg kg\({}^{-1}\))** & **Phosphorus (mg kg\({}^{-1}\))** & **CEC (meq/100 g)** \\ \hline
0–5 & NT & 11.6 (0.6) & 117 (5) & 198 (6) & 64 (8) \\  & CT & 10.6 (0.5) & 103 (7) & 155 (9) & 51 (5) \\ \hline
5–10 & NT & 10.8 (1.8) & 100 (11) & 179 (16) & 57 (7) \\  & CT & 10.2 (1.4) & 94 (8) & 136 (8) & 43 (4) \\ \hline
10–20 & NT & 7.9 (0.8) & 95 (8) & 100 (8) & 46 (7) \\  & CT & 7.8 (0.8) & 95 (6) & 120 (10) & 38 (8) \\ \hline
20–40 & NT & 7.6 (1.1) & 83 (10) & 60 (9) & 40 (9) \\  & CT & 7.4 (0.9) & 83 (6) & 94 (9) & 21 (5) \\ \hline
40–60 & NT & 6.1 (0.7) & 65 (5) & 40 (8) & 35 (6) \\  & CT & 5.9 (1.0) & 47 (7) & 60 (9) & 27 (6) \\ \hline  & 0–5 & 11.1 (0.9) a & 110 (13) a & 177 (20) a & 58 (11) a \\  & 5–10 & 10.5 (1.6) b & 97 (11) b & 158 (18) b & 50 (11) b \\  & 10–20 & 7.9 (0.8) c & 95 (7) b & 110 (15) c & 42 (8) c \\  & 20–40 & 7.5 (1.0) c & 83 (9) c & 77 (20) d & 31 (10) d \\  & 40–60 & 6.0 (0.9) d & 56 (11) d & 50 (13) e & 31 (7) d \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Chemical properties measured before the start of the experiment for no tillage (NT) and conventional tillage (CT) at each soil depth. Means (\(n\) = 3) with standard deviations followed by the same letter are not statistically different at the 0.05 significance level according to [PERSON]’s post hoc test. OC: organic carbon; CEC: cationic exchange capacity. in the deepest layer (56 mg kg\({}^{-1}\) at the 40-60 cm depth). [PERSON]'s post hoc test showed that each depth has significantly different potassium content than all the other depths, except 5-10 and 10-20 cm (97 and 95 mg kg\({}^{-1}\)). At the 0-10 cm horizon, soil under NT has higher potassium content than that under CT, in agreement with the results of studies on the effect of direct seeding on potassium [3]. Previous studies showed that under no-tillage conditions, the amount of potassium can be reduced with depth [24]. There was a highly significant interaction between the two factors (F value = 7.23 and _p_-value < 0.001). ANOVA indicated a significant difference between NT and CT for CEC (F value = 74.23 and _p_-value = 0.013), with a higher mean value for NT (48 meq/100 g) than for CT (36 meq/100 g), which can be explained by the increase in organic matter under NT vs. CT. Furthermore, highly significantly differences in CEC were observed relative to depth (F value = 51.55 and _p_-value < 0.001), with the highest mean value at the soil surface (58 meq/100 g at the 0-5 cm depth) and the lowest in the deepest layers (31 meq/100 g at the 20-40 and 40-60 cm depths). [PERSON]'s post hoc revealed significant differences between all depths, except the two deepest levels.