Fertility indicator

Grade

Low

Suitable

high

OM

<15

15 - 30

≥30

AN

<100

100 - 180

≥180

AP

<15

15 - 30

≥30

AK

<150

150 - 220

≥220

Ca

<6

6 - 10

≥10

Mg

<1.0

1.0 - 1.6

≥1.6

S

<16

16 - 30

≥30

B

<0.3

0.3 - 0.6

≥0.6

Cu

<0.5

0.5 - 1.0

≥1.0

Fe

<4.5

4.5 - 10

≥10

Mn

<10

10 - 20

≥20

Mo

<0.15

0.15 - 0.2

≥0.2

Zn

<1.0

1.0 - 2.0

≥2.0