Soil Science Society of America Journal,
Journal Year:
2025,
Volume and Issue:
89(2)
Published: March 1, 2025
Abstract
Nitrous
oxide
(N
2
O)
is
a
major
greenhouse
gas
and
its
emissions
from
soil
are
largely
driven
by
fertilizer
nitrogen
(N).
Sugar
beet
(
Beta
vulgaris
L.)
an
economically
important
crop;
however,
there
limited
studies
reporting
N
O
in
as
affected
fertilization.
The
2‐year
(2022–2023)
experiment
was
conducted
Nebraska,
to
evaluate
the
effects
of
different
rates
on
root
yield,
estimated
recoverable
sugar
(ERS),
emissions,
emission
factors
(EFs).
treatments
were
0%,
50%,
80%,
100%,
125%
(also,
150%
2023)
current
University
Nebraska
recommended
based
yield
goal
spring
test
N.
In
2023,
at
≥80%
had
higher
ERS
than
control.
Daily
fluxes
increased
exponentially
during
first
3–4
weeks
application.
Cumulative
linearly
with
both
years.
Emissions
least
50%
greater
2023
2022,
most
likely
moisture
2023.
EF
calculated
applied
(EF_N)
0.87%
1.48%
2022
respectively.
Fertilizer‐induced
(EF_fert)
0.71%
1.32%
average
annual
EF_fert
(1.02%)
very
close
Intergovernmental
Panel
Climate
Change
(IPCC)
default
1%,
suggesting
that
could
reasonably
estimate
understudied
crops
such
irrigated
beet.
Global Change Biology,
Journal Year:
2024,
Volume and Issue:
30(2)
Published: Feb. 1, 2024
Abstract
Flooded
paddy
soils
after
rewetting
dry
accompanied
by
extensive
nitrogen
fertilizer
input
are
important
anthropogenic
N
2
O
emitters
due
to
the
denitrification
process.
Owing
multiple
complex
denitrifying
sources,
however,
extent
which
biotic
(fungal
or
bacterial)
and
abiotic
(chemical)
contribute
total
emissions
remains
largely
unquantified.
Here
we
sampled
across
eight
provinces
where
most
of
flooded
were
in
China
explore
microbial
potentials
decipher
dynamics.
isotopocules
site
preference
(δ
15
SP
)
analyses
found
that
soils,
fungi‐mediated
was
largest
contributor
(51%–63%);
while
bacterial
chemical
denitrifications
contributed
12%–31%
12%–28%
emissions,
respectively.
Further,
using
labeling,
a
significant
spatial
heterogeneity
performance
observed
among
these
soils.
As
indicated
variance
partitioning
regression
analyses,
this
mainly
determined
soil
properties
(especially
organic
carbon
nitrogen)
rather
than
communities.
Our
findings
provide
insights
into
establishment
predictive
models
future
emission
from
global
considering
both
contributions.
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(7), P. 2970 - 2980
Published: Jan. 31, 2023
Paddy
fields
are
one
of
the
most
important
sources
nitrous
oxide
(N2O),
but
biogeochemical
N2O
production
mechanisms
in
soil
profile
remain
unclear.
Our
study
used
incubation,
dual-isotope
(15N-18O)
labeling
methods,
and
molecular
techniques
to
elucidate
characteristics
(0-60
cm)
during
summer
fallow,
rice
cropping,
winter
fallow
periods.
The
results
pointed
out
that
biotic
processes
dominated
(72.2-100%)
from
tillage
layer
accounted
for
91.0-98.5%
total
profile.
Heterotrophic
denitrification
(HD)
was
main
process
generating
N2O,
contributing
between
53.4
96.6%,
remainder
being
due
ammonia
oxidation
pathways,
which
further
confirmed
by
metagenomics
quantitative
polymerase
chain
reaction
(qPCR)
assays.
Nitrifier
(ND)
an
source,
0-46.6%
production,
showed
similar
trends
with
emissions.
Among
physicochemical
biological
factors,
ammonium
content
ratio
organic
matter
nitrate
were
driving
factors
affecting
contribution
ratios
pathways
HD
pathway,
respectively.
Moisture
pH
affect
norC-carrying
Spirochetes
thus
rate.
These
findings
confirm
importance
ND
help
impact
anthropogenic
activities,
including
tillage,
fertilization,
irrigation,
on
production.
