**3.3 Definition of the management zones**

Based on the maps created for each soil key property, the zoning procedure was applied by using Iso Cluster and Maximum Likelihood Classification tools. The descriptive statistics and the map produced are presented on **Table 5** and **Figure 7**, respectively.


### **Table 5.**

*Descriptive statistics of the management zones separated by layers 0–20 and 20–60 cm.*

*Pedometric Tools Applied to Zoning Management of Areas in Brazilian Semiarid Region DOI: http://dx.doi.org/10.5772/intechopen.88526*

The conditions to define the agricultural zones have to be adjusted according to available data and heterogeneity of soil properties in the study area, in this case located in a semiarid region.

Zone 1 presents the greater amount of Na in both layers, and it is associated with greater values of CEC as indicated by the mean values, than Zones 2 and 3. The same condition is verified for clay content, where Zone 1 has the greatest mean value in both layers (0–20 and 20–60 cm). As expected, sand content shows the

**Figure 7.** *Zoning of the study area according to selected soil key properties.*

dynamics and formation [66]. The spatial distribution of soil properties according

Based on the maps created for each soil key property, the zoning procedure was applied by using Iso Cluster and Maximum Likelihood Classification tools. The descriptive statistics and the map produced are presented on **Table 5** and

**Management zones MIN MAX Range Mean STD**

1 0.14 0.57 0.43 0.35 0.05 2 0.14 0.57 0.43 0.33 0.08 3 0.14 0.57 0.43 0.29 0.09

1 0.17 1.21 1.05 0.72 0.16 2 0.17 1.25 1.09 0.62 0.19 3 0.17 1.26 1.10 0.52 0.29

1 26.90 54.33 27.43 41.88 3.87 2 15.17 47.03 31.86 31.55 4.40 3 12.30 35.81 23.50 20.85 3.63

1 24.32 51.28 26.96 41.70 4.29 2 14.39 48.22 33.83 33.18 4.46 3 10.69 37.09 26.41 23.15 4.48

1 401.4 593.7 192.3 520.1 25.9 2 321.2 536.7 215.5 427.2 27.7 3 234.2 501.3 267.1 313.0 38.3

1 457.3 623.0 165.7 552.4 26.0 2 325.8 574.9 249.0 457.2 30.9 3 204.2 488.3 284.1 362.4 55.3

1 175.0 370.9 195.9 242.7 31.6 2 221.0 538.1 317.1 369.1 37.2 3 230.7 626.1 395.5 512.3 51.8

1 164.5 321.4 156.9 228.8 24.3 2 201.5 518.3 316.9 335.7 37.9 3 209.9 576.3 366.4 447.0 47.5

*Descriptive statistics of the management zones separated by layers 0–20 and 20–60 cm.*

to the predictive models is shown in **Figures 5** and **6**.

*Multifunctionality and Impacts of Organic and Conventional Agriculture*

**3.3 Definition of the management zones**

**Figure 7**, respectively.

Na (0–20 cm)

Na (20–60 cm)

CEC (0–20 cm)

CEC (20–60 cm)

Clay content (0–20 cm)

Clay content (20–60 cm)

Sand content (0–20 cm)

Sand content (20–60 cm)

**Table 5.**

**52**

*MIN, minimum; MAX, maximum; STD, standard deviation*

opposite pattern. Zone 1 occupies 42.6% of the area (1467 ha), and it has greater risk of salinization due to the higher mean values of Na. Even though Zone 1 has the greater mean values of CEC, it is associated to the high Na content and high content of clay, and possibly high clay activity (2:1). These properties limit the soil potential and irrigation management, further increasing salinization risks.

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Zone 2 is characterized by medium values of Na in both layers, when compared to Zones 1 and 3. The CEC values follow the same trend of Na, with medium values, and clay and sand contents are intermediary. This zone occupies 41.7% of the area with 1436 ha. Zone 2 presents medium effort and limitation to soil management, considering risks of salinization and requirements for irrigation control.

Zone 3 is characterized by the lowest values of Na and CEC in both layers; it has the soils with lowest clay contents and proportionally greatest sand contents. This zone occupies 15.7% of the area with 539 ha. Zone 3 has the lowest mean values of CEC and Na, which decrease risks of salinization; plus, the lower clay content is less limiting to soil mechanization.
