# Root System and Its Relations with Soil Physical and Chemical Attributes in Orange Culture
## 3 Results  
### Descriptive Data Statistics  
Tables S1 and S2 (Supplemental Materials) show the descriptive statistics obtained for the physical, chemical and root volume attributes from the experimental areas under Utisol. Analyzing the data obtained, it is observed that in the planting row there was an increase in the volume of roots at all depths evaluated in the area in which the triple operation equipment was used. For example, for the depth of 0.0-0.1 m, in the area in which the triple operation equipment (198 cm\({}^{3}\)) was used, there was an increase of approximately 147% compared to the use of minimum tillage (80 cm\({}^{3}\)) and 92% compared with subsoiler tillage (103 cm\({}^{3}\)).  
For the samples collected in the canopy projection, in general, the root volume was smaller than in the planting row, in all analyzed layers. However, as with the planting row, treatments using the triple operation equipment showed an increase in root volume, with a value of 51 cm\({}^{3}\) for triple operation, 36 cm\({}^{3}\) for subsoiler and 35 cm\({}^{3}\) for minimum tillage. There was a reduction in soil resistance to penetration, both in the planting row and in the projection of the canopy of the orange plants, in the area where the triple operation equipment was used. In both sampling sites, the value of this attribute exceeded 2.0 MPa in the 0.0-0.3 m layer, in an area under minimum tillage. In an area with triple operation and subsoiler, the values were close to 1.0 MPa.  
For the area under Oxisol, the descriptive analysis of the data is found in Tables S3 and S4 (Supplemental Materials). As in the area under Utisol, there was an increase in root volume in the planting row compared to the plant canopy projection, for layer 0.0-1.0 m, of the treatments that used the triple operation. In the planting row, in an area under minimum tillage of the soil, the root volume at total depth (0.0-1.0 m) did not exceed 30 cm\({}^{3}\). However, in the area where the triple operation equipment was used, the root volume was about 200 cm\({}^{3}\), representing an increase of almost 600% in root volume.  
For soil penetration to resistance, the behavior was also similar to that found in the area under Utisol, with higher values in area under minimum tillage compared to the areas where the triple operation and subsoiler implement were used. In relation to the organic carbon values found in the planting line, the area under minimum tillage and with the use of subsoiler showed higher values in comparison to the area where the triple operation occurred. In the area under minimum cultivation, the values found were: 1.9 g kg\({}^{-1}\) (0.0-0.1 m); 1.6 g kg\({}^{-1}\) (0.1-0.20 m); 1.2 g kg\({}^{-1}\) (0.2-0.3 m); 1.0 g kg\({}^{-1}\) (0.3-0.6 m) and 0.6 g kg\({}^{-1}\) (0.6-1.0 m). In an area under triple operation, they were: 1.5 g kg\({}^{-1}\) (0.0-0.1 m); 1.0 g kg\({}^{-1}\) (0.1-0.2 m); 0.8 g kg\({}^{-1}\) (0.2-0.3 m); 0.9 g kg\({}^{-1}\) (0.3-0.6 m) and 0.5 g kg\({}^{-1}\) (0.6-1.0 m), making it possible to observe a decrease in carbon in an area where equipment with triple operation was used.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Class** & **Range (cm\({}^{3}\))** & **Total Observations** \\ \hline
**Low** & 0.00–7.10 & 120 \\ \hline
**Medium** & 7.15–22.11 & 120 \\ \hline
**High** & 22.14–225.9 & 120 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Classification regarding root growth in volume (cm\({}^{3}\)), according to low, medium, and high classes and their respective limits, aiming at decision tree induction to predict the possible influences of the selected predictive attributes.