## 3 Results and Discussion
### Soil
#### 3.1.3 Total Nitrogen  
Table 5 shows total nitrogen mean values for the five soil depths (0-5, 5-10, 10-20, 20-40, and 40-60 cm) with the three nitrogen doses (20, 40, and 60 kg N ha\({}^{-1}\)) for each tillage type (NT and CT), and ANOVA results are presented in Table 6.  
ANOVA indicated no significant difference between the two tillage types (F value = 16.94 and _p_-value = 0.054), with mean values of 595 and 572 mg kg\({}^{-1}\) for CT and NT, respectively. In contrast, there were highly significant differences between the three nitrogen doses (F value = \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Soil Properties** & \multicolumn{2}{c}{**Total Nitrogen**} & \multicolumn{2}{c}{**Ammonium**} & \multicolumn{2}{c}{**Nitrates**} \\ \hline
**Source of Variation** & **F Value** & _p_**-Value** & **F Value** & _p_**-Value** & **F Value** & _p_**-Value** \\ \hline \hline Village (T) & 16.94 & 0.054 ns & 325.14 & 0.003 ** & 50.10 & 0.019 * \\ Nitrogen (N) & 33.55 & \textless{}0.001 *** & 0.60 & 0.573 ns & 30.74 & \textless{}0.001 *** \\ Depth (D) & 80.76 & \textless{}0.001 *** & 5.94 & 0.001 ** & 11.81 & \textless{}0.001 *** \\ T \(\times\) N & 32.62 & \textless{}0.001 *** & 9.25 & 0.008 ** & 3.65 & 0.075 ns \\ T \(\times\) D & 3.40 & 0.016 * & 15.05 & \textless{}0.001 *** & 7.83 & \textless{}0.001 *** \\ N \(\times\) D & 19.91 & \textless{}0.001 *** & 7.62 & \textless{}0.001 *** & 3.76 & 0.002 ** \\ T \(\times\) N \(\times\) D & 9.01 & \textless{}0.001 *** & 4.88 & \textless{}0.001 *** & 6.70 & \textless{}0.001 *** \\ \hline \hline \end{tabular}
\end{table} 
Table 6: ANOVA results for soil properties measured at the end of the experiment. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Nitrogen** & **Tillage/Depth** & \multirow{2}{*}{**0-5**} & **5-10** & **10-20** & **20-40** & **40-60** & **Mean** & **Mean** \\ (kg N ha\({}^{-1}\)) & & & & & & & & \\ \hline \hline \multirow{3}{*}{20} & NT & 700 (50) & 770 (90) & 280 (30) & 560 (40) & 840 (80) & 630 (197) & \multirow{3}{*}{585 (166) A} \\  & CT & 420 (20) & 520 (50) & 490 (70) & 590 (40) & 680 (110) & 540 (127) & \\ \hline \multirow{3}{*}{40} & NT & 870 (120) & 560 (80) & 280 (50) & 350 (60) & 700 (50) & 552 (215) & \multirow{3}{*}{539 (189) B} \\  & CT & 770 (60) & 490 (60) & 420 (60) & 350 (80) & 600 (60) & 526 (165) & \\ \hline \multirow{3}{*}{60} & NT & 560 (50) & 630 (90) & 490 (130) & 420 (40) & 570 (80) & 534 (109) & \multirow{3}{*}{626 (186) A} \\  & CT & 930 (90) & 910 (60) & 560 (40) & 350 (70) & 840 (40) & 718 (213) & \\ \hline \multirow{3}{*}{Mean} & NT & 710 (105) & 653 (122) & 350 (113) & 443 (138) & 703 (141) & 572 (183) & \multirow{3}{*}{595 (190)} \\  & CT & 707 (204) & 640 (197) & 590 (88) & 430 (165) & 707 (133) & 595 (190) & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Total nitrogen content (mg kg\({}^{-1}\)) measured at the end of the experiment for each nitrogen dose (kg N ha\({}^{-1}\)), tillage type, and soil depth (cm). 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. NT= no tillage, CT= conventional tillage. 33.55 and _p_-value \(<\) 0.001) and the five depths (F value = 80.76 and _p_-value \(<\) 0.001). [PERSON]'s post hoc test showed no significant difference between 20 and 60 kg N ha\({}^{-1}\) with higher total nitrogen content (585 and 626 mg kg\({}^{-1}\), respectively) compared to 40 kg N ha\({}^{-1}\) with lower content (539 mg kg\({}^{-1}\)). Regarding soil depths, there were three groups: 0-5 and 40-60 cm, which did not significantly differ (708 and 705 mg kg\({}^{-1}\); 5-10 cm (647 mg kg\({}^{-1}\)); and 10-20 and 20-40 cm, which did not significantly differ (420 and 437 mg kg\({}^{-1}\), respectively). For 20 and 40 kg N ha\({}^{-1}\), the total surface nitrogen content was higher in NT than in CT, whereas for 60 kg N ha\({}^{-1}\), CT was higher than NT.