Indicator

Type

x1

x2

Function

SOM (g∙kg−1)

M (x)

6

20

M ( x ) = { 0.1 x < x 1 0.9 × x x 1 x 2 x 1 + 0.1 x 1 < x < x 2 1 x > x 2

L ( x ) = { 1 x < x 1 1 0.9 × x x 1 x 2 x 1 x 1 < x < x 2 0.1 x > x 2

R ( x ) = { 0.1 x < x 1 0.9 × x x 1 r 1 x 1 + 0.1 x 1 < x < r 1 1 r 1 < x < r 2 1 0.9 × x r 2 x 2 r 2 r 2 < x < x 2 0.1 x > x 2

TN (g∙kg−1)

M (x)

0.3

1.2

AP (mg∙kg−1)

M (x)

5

15

AK (mg∙kg−1)

M (x)

40

200

EC (mS∙cm−1)

L (x)

0.2

4

BD (g∙cm−3)

L (x)

1.25

1.55

Clay %

R (x)

5

40

pH

R (x)

5.5

9.5