Source of variation

df

log (IRB number/g dry soil)

Fe II (µg/g dry soil)

F

p

F

p

Drainage

3

3.292

0.024^*

0.464

0.708^ns

Period

11

22.153

<0.0001^**

21.759

<0.0001^**

Drainage x Period

33

2.249

0.001^**

1.935

0.007^**