## 3 Results
In contrast, inoculated plots showed no significant variation, suggesting that inoculation may reduce P availability or alter its stabilization in the soil. Furthermore, inorganic phosphorus (Pi) also increased exponentially in non-inoculated treatments, reinforcing the contrasting dynamics between treatments. Notably, inoculated plots had 32.5% less labile P compared to non-inoculated ones, which may impact nutrient accessibility for crops. These results highlight the complex interaction between microbial activity and phosphorus forms in conservationist systems. The regression analysis indicated that increasing P\({}_{2}\)O\({}_{5}\) doses resulted in a positive exponential increase in both labile and moderately labile phosphorus fractions in the 0.00-0.10 m soil layer under non-inoculated conditions. The moderately labile fraction showed higher phosphorus concentrations compared to the labile fraction, with R\({}^{2}\) values of 0.9472 and 0.9109, respectively (Figure 9). Additionally, the inorganic phosphorus fraction  
Figure 8: Percentage variation in soil chemical attributes between the 2021/2022 and 2023/2024 harvests as a function of residual phosphate (P) fertilization and inoculation with _Azospirillum brasilense_ (Inoc) in the 0.00–0.10 and 0.10–0.20 m layers of soil under a no-tillage system. Selvtria/MS. P: phosphorus; S: sulfur; K: potassium; Ca: calcium; Mg: magnesium; H+Al: potential acidity (hydrogen plus aluminum); BS: base saturation; CEC: cation exchange capacity; V: base saturation index; m: aluminum saturation; OM: organic matter; pH: hydrogen potential. also increased exponentially with higher P\({}_{2}\)O\({}_{5}\) doses, presenting an R\({}^{2}\) of 0.943 (Figure 10). These results highlight the direct influence of phosphate fertilization on the accumulation of different phosphorus fractions in the soil. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Treatment** & **Lab** & **Mod Lab** & **N Lab** & **Pi** & **Po** & **P Tot** \\ \cline{2-7}  & & & & **mg kg\({}^{-1}\)** & & \\ \hline \multicolumn{7}{c}{P\({}_{2}\)O\({}_{5}\) doses (kg ha\({}^{-1}\)) (P)} \\ \hline
0 & 13.09 & 149.68 & 224.95 & 42.88 & 96.99 & 387.72 \\
30 & 14.33 & 149.31 & 228.21 & 46.53 & 92.14 & 393.77 \\
60 & 13.78 & 148.32 & 220.37 & 43.72 & 94.80 & 382.45 \\
120 & 15.12 & 150.92 & 224.06 & 48.14 & 91.74 & 390.41 \\
240 & 26.01 & 167.01 & 223.43 & 57.29 & 98.30 & 415.40 \\ \hline \multicolumn{7}{c}{Inoculation (I)} \\ \hline Without & 13.26 b & 150.48 & 217.34 & 45.54 & 94.10 & 381.17 \\ With & 19.66 a & 155.61 & 231.06 & 49.88 & 95.49 & 406.33 \\ \hline Test—P & 0.0001 ** & 0.014 ** & 0.994 ns & 0.003 ** & 0.394 ns & 0.521 ns \\ \hline Test—I & 0.0001 ** & 0.170 ns & 0.227 ns & 0.069 ns & 0.583 ns & 0.053 ns \\ \hline Test—P \(\times\) I & 0.0001 ** & 0.017 ** & 0.785 ns & 0.002 ** & 0.850 ns & 0.774 ns \\ \hline CV\% & 19.49 & 07.55 & 15.73 & 15.26 & 8.39 & 10.06 \\ \hline \multicolumn{7}{c}{Means followed by different letters in the column for different treatments differed according to the LSD post-hoc test at the 5% probability level. **: significant at 1% probability by the LSD post-hoc test. ns: not significant. CV: coefficient of variation; Lab: labile phosphorus; Mod Lab: moderately labile phosphorus; N Lab: non-labile phosphorus; Pi: inorganic phosphorus; Po: organic phosphorus; P Tot: total phosphorus.} \\ \end{tabular}
\end{table} 
Table 19: Mean values for soil phosphorus fractionation in the 0.00–0.10 m layer, labile phosphorus (Lab), moderately labile phosphorus (Mod Lab), non-labile phosphorus (N Lab), inorganic phosphorus (Pi), organic phosphorus (Po), and total phosphorus (P Tot) after _Brachiaria brizantha_ cv. Piata fallow in a no-tillage system, considering the residual effect of phosphate fertilization and the inoculation of preceding grasses with _A. brasilense_. Selvriia/MS, 2023/2024.