The
agricultural
landscape
in
the
US
Midwest
faces
significant
environmental
challenges
associated
with
annual
crop
rotations,
particularly
intensive
cultivation
of
soybeans
and
maize
that
is
heavily
reliant
on
nitrogen
(N)
fertilizers.
In
contrast,
perennial
biomass
crops
are
gaining
attention
for
their
notable
benefits,
such
as
efficient
nutrient
cycling,
enhanced
water
quality,
reduced
soil
erosion,
increased
organic
carbon
(C),
overall
health
improvement.
Extracellular
enzymes
(EEs),
produced
mainly
by
microorganisms
but
also
plant
roots,
largely
mediate
matter
(SOM)
decomposition.
These
EEs
known
to
play
a
substantial
role
maintaining
catalyzing
nearly
all
important
transformations
cycling
C,
N
other
nutrients.
Microbial
enzyme-mediated
processes
(e.g.,
SOM
decomposition
cycling)
can
be
evaluated
based
kinetic
parameters
EEs.
Two
defined
Michaelis-Menten
(M-M)
model
enzyme
kinetics:
maximum
reaction
velocity
(Vmax)
M-M
constant
(Km)
represents
substrate
concentration
at
one-half
Vmax.
this
dissertation,
I
first
investigated
impact
[maize-soybean
rotation
(CS)]
[fertilized
prairie
(PrF)
unfertilized
(Pr)]
two
extracellular
(EEs)
involved
C
cycling:
β-glucosidase
(BGase)
leucine
aminopeptidase
(LAPase),
respectively.
found
N-fertilized
affected
Vmax
not
Km
both
enzymes.
BGase
PrF
system
compared
CS
likely
driven
greater
microbial
activity
system.
LAPase
Pr
fertilized
systems
was
due
demand.
Additionally,
observed
needed
achieve
exceeded
concentrations
typically
employed
many
studies,
suggesting
necessity
determine
saturation
curve
each
treatment
before
conducting
similar
assays.
Most
potential
(PEA)
studies
focus
surface
horizons
where
nutrients
concentrated,
influence
various
properties
PEA
subsoil
remains
unexplored.
Recognizing
changes
these
depth,
variations
may
interact
long-term
management
practices.
To
better
understand
land-use
conversion
PEA,
conducted
assessments
hydrolytic
oxidative
PEAs
1-m
depths
CS,
PrF,
cropping
systems.
results
revealed
depth
profiles
were
strongly
influenced
treatments,
had
impacts
than
This
dissertation
addresses
puzzle
miscanthus
(Miscanthus
×
giganteus).
Through
comprehensive
analysis
dynamics
–
combining
potentially
mineralizable
(PMN),
extractable
pools,
amino
compound
research
unveiled
complex
interactions
between
processes.
Despite
PMN
under
across
fertilizer
rates,
activities
acquisition
remained
unaffected.
Notably,
significantly
elevated
total
matter,
providing
explanation
"missing
source
N"
phenomenon.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Янв. 2, 2025
Effective
soil
organic
carbon
(SOC)
management
can
mitigate
the
impact
of
climate
warming.
However,
response
different
SOC
fractions
to
warming
in
abandoned
croplands
remains
unclear.
Here,
categorizing
into
particulate
and
mineral-associated
(POC
MAOC)
with
physical
fractionation,
we
investigate
responses
POC
MAOC
content
temperature
sensitivity
(Q10)
through
a
3-year
situ
experiment
(+1.6
°C)
across
12
sites
China
(latitude:
22.33–46.58°N).
Our
results
indicate
that
unchanged
while
significantly
increases
under
changes
are
mainly
influenced
by
root
biomass
microbial
necromass
changes,
respectively.
The
Q10
is
lower
than
regardless
or
control
treatment,
suggesting
represents
most
persistent
least
vulnerable
fraction
within
SOC.
Collectively,
sequestration
stable
be
enhanced
short-term
Natural
recovery
generally
benefits
accrual
croplands,
but
on
this
ecosystem
authors
showed
enhances
these
lands.
Geoderma,
Год журнала:
2023,
Номер
436, С. 116558 - 116558
Опубликована: Июнь 15, 2023
Accurate
quantification
of
soil
organic
carbon
(OC)
pools
is
essential
to
study
the
dynamics
OC
in
soils.
Therefore,
matter
often
separated
into
physical
fractions
with
distinct
turnover
times,
e.g.
particulate
(POM)
and
mineral-associated
(MAOM),
after
which
their
content
measured.
Calcareous
soils
are
under-represented
such
fractionation
studies,
because
required
analytical
differentiation
between
inorganic
(IC)
not
straightforward
implies
more
processing
time,
sample
mass
equipment.
Here,
we
review
performance
four
methods
quantify
POM
MAOM
containing
3–16
g
IC
kg−1
10–25
(n
=
16).
We
assessed
similarity
consistency
data
obtained
different
methods.
Furthermore,
checked
how
ability
distinguish
from
was
influenced
by
particular
dispersion
sodium
hexametaphosphate
(SHMP).
The
were:
1)
Elemental
analysis
removal
acid
fumigation
(OCfum);
2)
aqueous
(OCaq);
3)
as
determined
Rock-Eval
6
thermal
(OCRE6);
4)
loss
on
ignition
subsequent
difference
total
(OCLOI).
found
that
OCfum,
OCaq,
OCLOI
produced
similar
contents
for
bulk
soils,
whereas
OCRE6
results
were
slightly
but
significantly
lower.
Total
recovered
summed
contents.
In
contrast,
OCaq
higher
than
respective
(108–112%),
especially
high
IC/OC
ratios.
show
this
caused
operational
artefacts
or
chemical
changes
occurred
during
fractionation,
rather
likely
indicated
error
propagation.
conclude
all
4
can
reliably
calcareous
optimal
choice
depends
accuracy
available
mass,
lab
equipment
time.
Based
our
findings
practical
considerations,
provide
guidance
selection
most
method
Research Square (Research Square),
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 6, 2025
AbstractBackground
and
Aims:
Highly
weathered
tropical
forests
are
widely
recognized
as
nitrogen
(N)-rich
phosphorus
(P)-poor,
the
input
of
nutrienteffects
soil
carbon
(C)
cycling
storage
in
these
ecosystems.
In
topsoil,
short-term
nutrient
additionmay
not
only
effect
organic
C
(SOC)
pools
directly,
but
also
impact
conversion
process
indirectly
through
altering
microbial
use
efficiency
(CUE).
However,
effects
addition
on
accumulation
mechanisms
remain
unclear.
The
aim
this
study
was
to
clarify
SOC
responding
addition.
Methods:
This
conducted
a
one-year
N
P
additions
experiment
forest
Hainan,
China.
SOC,
fractions
(POC
MAOC),
biomass,
enzyme
activities,
physicochemical
properties
at
depths
0–10
cm,
10–20
cm
20–40
were
measured.
Results:
results
showed
that
increased
(8.91–20.03%),
POC
(6.65–24.90%),
MAOC
(8.74–19.89%)
topsoil
(0–10
cm),
whereas
no
significant
changes
occurred
subsoil
(20–40
cm).
Pearson’s
correlation
analysis
revealed
litter
biomass
CUE
significantly
positively
correlated
with
SOC.
partial
least
squares-path
model
influences
by
characteristics.
Conclusions:These
suggested
decreased
activities.
Such
information
could
provide
insight
understand
pool
forest.
Geoderma,
Год журнала:
2023,
Номер
433, С. 116432 - 116432
Опубликована: Март 20, 2023
Soils
in
alpine
ecosystems
store
a
large
amount
of
organic
carbon
(C)
with
significant
portion
sorbed
to
reactive
soil
minerals.
However,
impacts
ongoing
global
change
factors
on
mineral-associated
C
dynamics
are
highly
uncertain
regions.
Utilizing
multi-factor
simulation
experiment
Tibetan
meadow
since
May
2015,
we
examined
the
effects
air
warming,
nitrogen
input
and
precipitation
changes
calcium
(Ca)-
iron
(Fe)-associated
2019–2020.
We
found
no
difference
Ca-
or
Fe-associated
concentrations
among
treatments.
both
were
significantly
higher
2020
abnormally
high
rainfall
(+40%)
than
2019
normal
rainfall.
High
increased
moisture,
reduced
aggregation
released
dissolved
C.
moisture
promoted
formation
C,
likely
through
facilitating
Ca-binding
clay
surface
as
bridge
for
mineral-C
complexes
increasing
solubility
Fe
oxides.
In
contrast,
low
degree
water
addition
(<30%)
immediately
following
each
event
field
did
not
affect
either
Taken
together,
our
results
provide
new
insights
into
potential
mechanisms
which
interannual
variability
controls
persistence
ecosystems,
suggesting
that
pattern
may
dominate
its
impact
retained
by
