In 2009 and 2011, as a
result of frequent rain events (Fig. 1), soil Eh dropped
down below 0 mV in most cases during the MSA period,
while it ranged from −245 to 364 mV during the
MSA period in 2008 and 2010. Soil Eh during the drywet
alternation period in 2008 was not measured due
to problems with the oxidation-reduction potential meter.
No significant difference in soil Eh was found between
the treatments in each year.