Using Soil Apparent Electrical Conductivity to Optimize Sampling of Soil Penetration Resistance and to Improve the Estimations of Spatial Patterns of Soil Compaction
Table 1
Statistical parameters of the apparent electrical conductivity (ECa) measured with EM38, in vertical and horizontal modes, and electrical conductivity (ECveris) and soil resistance to penetration (PR) measured with VERIS P3000 at successive layers.
Variable
Units
Min.
Max.
Mean
Variance
CV
Skewness
Kurtosis
ECa-V
mS m−1
1859
4.13
20.13
11.21
6.12
22.07
0.485
−0.243
0.071Ln
ECa-H
1859
6.63
20.00
12.12
3.22
14.81
0.839
1.285
0.092Ln
140
1.07
12.27
3.17
7.64
87.00
2.523
6.259
0.317Ln
134
1.58
17.84
5.94
23.48
81.47
1.360
0.798
0.317Ln
131
1.36
8.14
3.18
2.77
52.34
1.562
2.643
0.317Ln
102
1.13
7.79
3.04
2.48
51.88
1.279
1.966
0.317Ln
84
0.62
9.30
4.11
6.02
59.65
−0.179
−1.739
0.330Ln
72
0.80
9.41
5.46
6.76
47.57
−3.680
−10.143
0.361Ln
63
2.79
8.05
5.95
2.83
28.29
−36.860
−197.233
0.404Ln
32
2.13
7.31
5.45
2.49
28.92
−49.662
−418.618
0.432Ln
27
3.17
6.81
5.29
1.27
21.34
−265.192
−7150.197
0.513Ln
507
1.40
9.32
3.83
5.74
62.47
−1.511
−14.054
0.317Ln
278
0.62
7.94
4.51
5.09
49.96
−39.185
−39.185
0.330Ln
MPa
140
0.30
2.47
0.64
0.18
67.30
1.169
1.858
0.317Ln
134
1.10
3.28
2.16
0.40
29.41
−26.517
−121.478
0.317Ln
131
1.49
3.53
2.63
0.32
21.78
−0.423
−0.677
0.317Ln
102
1.68
4.85
3.05
0.53
23.89
0.265
0.025
0.317Ln
84
1.74
5.54
3.12
0.94
31.17
−0.211
4.172
0.330Ln
72
1.92
5.32
3.04
0.86
30.43
−19.154
−60.403
0.381Ln
63
1.60
5.59
3.33
1.46
36.31
−16.549
−88.761
0.404Ln
32
1.54
4.85
3.09
0.99
36.26
−34.572
−285.556
0.432Ln
27
1.62
4.43
3.02
0.87
30.87
−47.972
−495.883
0.449Ln
507
1.18
3.06
2.12
0.26
24.05
−48.771
−233.173
0.317Ln
278
1.95
5.54
3.40
0.98
29.21
−33.401
−207.070
0.330Ln
: number of measures (maximum six measurements in each location for ECveris and PR); Min.: minimum value; Max.: maximum value; CV: coefficient of variation (%); : normality of the data for test of Kolmogorov-Smirnov ( < 0.01, n: normality and Ln: lognormality).
