Environmental Science & Technology,
Journal Year:
2022,
Volume and Issue:
56(16), P. 11878 - 11887
Published: Aug. 8, 2022
Dark
formation
of
hydroxyl
radicals
(•OH)
from
soil/sediment
oxygenation
has
been
increasingly
reported,
and
solid
Fe(II)
is
considered
as
the
main
electron
donor
for
O2
activation.
However,
role
organic
matter
(SOM)
in
•OH
production
not
clear,
although
it
represents
an
important
pool
subsurface.
In
this
study,
reduced
humic
acid
(HAred)
was
investigated
at
pH
7.0.
linearly
correlated
with
electrons
released
HAred
suspension.
Solid
transferred
rapidly
to
via
surface-reduced
moieties
(hydroquinone
groups),
which
fueled
by
slow
transfer
inside
HA.
Cycling
dissolved
HA
between
oxidized
states
could
mediate
enhancement.
Modeling
results
predicted
that
SOM
played
or
even
dominant
soils
sediments
possessing
high
molar
ratios
SOC/Fe(II)
(e.g.,
>39).
The
significant
contribution
further
validated
modeling
88
soils/sediments
literature.
Therefore,
should
be
carefully
comprehensively
understand
SOM-rich
subsurface
environments.
GCB Bioenergy,
Journal Year:
2021,
Volume and Issue:
13(11), P. 1731 - 1764
Published: July 27, 2021
Abstract
We
synthesized
20
years
of
research
to
explain
the
interrelated
processes
that
determine
soil
and
plant
responses
biochar.
The
properties
biochar
its
effects
within
agricultural
ecosystems
largely
depend
on
feedstock
pyrolysis
conditions.
describe
three
stages
reactions
in
soil:
dissolution
(1–3
weeks);
reactive
surface
development
(1–6
months);
aging
(beyond
6
months).
As
ages,
it
is
incorporated
into
aggregates,
protecting
carbon
promoting
stabilization
rhizodeposits
microbial
products.
Biochar
persists
for
hundreds
thousands
years.
By
increasing
pH,
porosity,
water
availability,
biochars
can
create
favorable
conditions
root
functions.
Biochars
catalyze
biotic
abiotic
reactions,
particularly
rhizosphere,
increase
nutrient
supply
uptake
by
plants,
reduce
phytotoxins,
stimulate
development,
resilience
disease
environmental
stressors.
Meta‐analyses
found
that,
average,
P
availability
a
factor
4.6;
decrease
tissue
concentration
heavy
metals
17%–39%;
build
organic
through
negative
priming
3.8%
(range
−21%
+20%);
non‐CO
2
greenhouse
gas
emissions
from
12%–50%.
show
average
crop
yield
increases
10%–42%
with
addition,
greatest
low‐nutrient
P‐sorbing
acidic
soils
(common
tropics),
sandy
drylands
due
retention
holding
capacity.
Studies
report
wide
range
diversity
contexts
which
have
been
applied.
Crop
yields
strongly
if
site‐specific
constraints
limitations
are
mitigated
appropriate
formulations.
be
tailored
address
site
selection,
modifying
conditions,
pre‐
or
post‐production
treatments,
co‐application
mineral
fertilizers.
demonstrate
how,
when
used
wisely,
mitigates
climate
change
supports
food
security
circular
economy.
Global Change Biology,
Journal Year:
2021,
Volume and Issue:
27(11), P. 2478 - 2490
Published: March 13, 2021
Paddy
soils
make
up
the
largest
anthropogenic
wetlands
on
earth,
and
are
characterized
by
a
prominent
potential
for
organic
carbon
(C)
sequestration.
By
quantifying
plant-
microbial-derived
C
in
across
four
climate
zones,
we
identified
that
accrual
is
achieved
via
contrasting
pathways
paddy
upland
soils.
Paddies
39%-127%
more
efficient
soil
(SOC)
sequestration
than
their
adjacent
counterparts,
with
greater
differences
warmer
cooler
climates.
Upland
replenished
C,
whereas
enriched
proportion
of
plant-derived
because
retarded
microbial
decomposition
under
anaerobic
conditions
induced
flooding
paddies.
Under
both
land-use
types,
maximal
contribution
plant
residues
to
SOC
at
intermediate
mean
annual
temperature
(15-20°C),
neutral
(pH~7.3),
low
clay/sand
ratio.
contrast,
high
(~24°C),
pH
(~5),
large
ratio
favorable
strengthening
necromass.
The
necromass
waterlogged
paddies
climates
likely
due
fast
anabolism
from
bacteria,
fungi
unlikely
be
involved
as
they
aerobic.
In
scenario
conversion
upland,
total
504
Tg
may
lost
CO
Carbon Research,
Journal Year:
2022,
Volume and Issue:
1(1)
Published: June 18, 2022
Abstract
Iron
(Fe)
minerals
play
an
important
role
in
stabilizing
soil
organic
carbon
(SOC).
Fe-mediated
SOC
protection
is
mainly
achieved
through
adsorption,
co-precipitation,
or
aggregation.
However,
newly
emerging
evidence
indicates
that
the
electron
transfer
of
Fe
exerts
a
crucial
influence
upon
turnover.
In
this
review,
we
address
pathways
mineral-associated
(Fe-SOC)
formation
and
decomposition,
summarize
biogeochemical,
including
redox
reactions,
physical
processes
control
cycling.
The
reduction
can
release
from
Fe-SOC
coprecipitates
Fe(III)
cemented
micro-aggregates,
with
process
also
releasing
CO
2
metabolic
coupling
oxidation
reduction.
abiotic
Fe(II)
by
oxidants
oxidize
to
produce
due
reactive
oxygen
species
production.
Therefore,
functional
roles
on
sequestration
may
be
double-edged
sword,
these
are
rarely
explored
concurrently.
We
conclude
stability
depend
properties
mineral,
edaphic
properties,
anthropogenic
influence.
highlight
knowledge
gaps
promising
directions
future
research
redox-dynamic
environments
optimize
storage
soil.
Graphical
Fundamental Research,
Journal Year:
2022,
Volume and Issue:
2(5), P. 697 - 707
Published: Feb. 15, 2022
Plant
roots
are
one
of
the
major
mediators
that
allocate
carbon
captured
from
atmosphere
to
soils
as
rhizodeposits,
including
root
exudates.
Although
rhizodeposition
regulates
both
microbial
activity
and
biogeochemical
cycling
nutrients,
effects
particular
exudate
species
on
soil
fluxes
key
rhizosphere
microorganisms
remain
unclear.
By
combining
high-throughput
sequencing,
q-PCR,
NanoSIMS
analyses,
we
characterized
bacterial
community
structure,
quantified
total
bacteria
depending
chemistry,
analyzed
consequences
mobility
mineral-protected
carbon.
Using
well-controlled
incubation
experiments,
showed
three
most
abundant
groups
exudates
(amino
acids,
carboxylic
sugars)
have
contrasting
release
dissolved
organic
(DOC)
bioavailable
Fe
in
an
Ultisol
through
disruption
organo-mineral
associations
alteration
communities,
thus
priming
matter
decomposition
rhizosphere.
High
resolution
(down
50
nm)
images
mineral
particles
indicated
iron
silicon
co-localized
significantly
more
following
amino
acid
inputs
than
treatments
without
or
with
acids.
The
application
sugar
strongly
reduced
diversity
impacting
mobilization.
Carboxylic
acids
increased
prevalence
Water Research,
Journal Year:
2022,
Volume and Issue:
220, P. 118655 - 118655
Published: May 24, 2022
Freshwater
suspended
particulate
matter
(SPM)
plays
an
important
role
in
many
biogeochemical
cycles
and
serves
multiple
ecosystem
functions.
Most
SPM
is
present
as
complex
floc-like
aggregate
structures
composed
of
various
minerals
organic
from
the
molecular
to
organism
level.
Flocs
provide
habitat
for
microbes
feed
larger
organisms.
They
constitute
microbial
bioreactors,
with
prominent
roles
carbon
inorganic
nutrient
cycles,
transport
nutrients
well
pollutants,
affecting
sediments,
inundation
zones,
ocean.
Composition,
structure,
size,
concentration
flocs
are
subject
high
spatiotemporal
variability.
Floc
formation
processes
compositional
or
morphological
dynamics
can
be
established
around
three
functional
components:
phyllosilicates,
iron
oxides/(oxy)hydroxides
(FeOx),
extracellular
polymeric
substances
(EPS).
These
components
their
interactions
increase
heterogeneity
surface
properties,
enhancing
flocculation.
Phyllosilicates
exhibit
intrinsic
heterogeneities
charge
hydrophobicity.
preferential
substrates
precipitation
attachment
reactive
FeOx.
FeOx
form
patchy
coatings
on
minerals,
especially
which
heterogeneities.
Both,
phyllosilicates
strongly
adsorb
natural
(NOM),
preferentially
certain
EPS.
EPS
comprise
heterogeneous
properties
that
make
them
a
sticky
mixture,
Microbial
metabolism,
thus
release,
supported
by
adsorption
capacity
favorable
composition
supply
essential
Fe.
Global Change Biology,
Journal Year:
2023,
Volume and Issue:
29(22), P. 6188 - 6200
Published: Sept. 21, 2023
Abstract
Plant‐
and
microbially
derived
carbon
(C)
are
the
two
major
sources
of
soil
organic
matter
(SOM),
their
ratio
impacts
SOM
composition,
accumulation,
stability,
turnover.
The
contributions
key
factors
defining
plant
microbial
C
in
along
profile
not
well
known.
By
leveraging
nuclear
magnetic
resonance
spectroscopy
biomarker
analysis,
we
analyzed
three
types
using
regional‐scale
sampling
combined
these
results
with
a
meta‐analysis.
Topsoil
(0–40
cm)
was
rich
carbohydrates
lignin
(38%–50%),
whereas
subsoil
(40–100
contained
more
proteins
lipids
(26%–60%).
proportion
increases,
while
decreases
content.
decrease
rate
to
plant‐derived
(C
M:P
)
content
23%–30%
faster
topsoil
than
regional
study
had
high
potential
stabilize
through
intensive
transformations
necromass
formation.
Plant
input
mean
annual
temperature
were
main
topsoil,
fungi‐to‐bacteria
clay
influencing
.
Combining
meta‐analysis,
highlighted
contribution
litter
up
1‐m
depth
elucidated
regulating
long‐term
preservation.
