Climate-proofing the world’s soil

International

-DW News

Brussels,
Sep
21:
Soil
is
easy
to
overlook
as
the
dirt
on
our
shoes,
the
realm
of
gardeners
and
farmers
and
nothing
much
to
do
with
anyone
else.
But
it
is,
of
course,
vital
to
our
survival.
As
without
soil,
growing
food
becomes
a
problem.

A
mixture
of
mineral
and
organic
waste
that
teems
with
minute
life,
soil
is
complex
matter.
An
inch
of
nutrient-rich
topsoil,
so
integral
to
productive
agricultural
land,
can
take
hundreds
of
years
to
develop.
But
it
takes
far
less
time
to
become
dried
out
and
potentially
eroded
as
a
result
of
drought
—
such
as
the
one
that
has
held
Europe
in
its
grip
this
summer.

“What
we
are
seeing
is
that
now
droughts
are
becoming
so
intense,
and
the
soil
erosion
is
also
becoming
more
intense,”
said
Lizeth
Vasconez
Navas,
a
researcher
at
the
University
of
Hamburg’s
Institute
of
Soil
Science.

While
it
might
be
counterintuitive
after
months
of
little
rain,
a
heavy
downpour
is
not
necessarily
a
blessing
for
farmers.
Certain
soils,
especially
those
containing
clay,
can
become
so
dry
that
they
are
no
longer
able
to
effectively
absorb
water,
so
when
the
rains
do
fall,
the
water
ends
up
flowing
over
the
soil,
washing
away
tons
of
earth
and
valuable
nutrients,
and
potentially
leading
to
flash
flooding.

Russia
and
climate
change
dominate
UN
meeting

In
this
experiment
Dr
Rob
Thompson
of

@UniRdg_Met
shows
just
how
long
it
takes
water
to
soak
into
parched
ground,
illustrating
why
heavy
rainfall
after
a

#drought
can
be
dangerous
and
might
lead
to
flashfloods.

@R0b1et
@UniRdg_water
pic.twitter.com/zbb3xLTXdK

—
Uni
of
Reading
(@UniofReading)

August
10,
2022

Nicole
Wellbrock,
a
soil
expert
from
the
Thünen
Institute
for
Forest
Ecosystems,
northeast
of
Berlin
says
climate
change
has
made
sudden,
extreme
rain
showers
more
common
and
the
right
sort
of
precipitation
rarer.
“We
would
actually
need
long,
steady
rainfall,
which
seeps
in
slowly
and
moistens
the
soil.”

So
how
can
soil
be
protected?

To
prevent
dried
out
soils
from
being
lost
to
erosion,
experts
say
it’s
crucial
to
establish
new
ground
cover
as
quickly
as
possible.

Quick-growing
plants
can
help
prevent
further
soil
loss
while
helping
to
replenish
lost
nutrients
by
fixing
nitrogen
in
the
soil.

These
“cover
crops”
such
as
legumes,
wheat,
oat
and
barley
can
act
as
sort
of
a
natural
shield,
slowing
evaporation
and
retaining
moisture
while
reducing
temperature
at
ground
level.

They
can
replenish
the
health
of
the
soil
over
time
by
controlling
erosion,
suppressing
weeds
and
pests,
stabilizing
root
systems
and
increasing
organic
matter,
according
to
a
2021
report
from
The
Council
on
Energy,
Environment
and
Water,
an
Indian
nonprofit
research
institution.

Another
way
of
retaining
soil
moisture
is
by
applying
a
layer
of
mulch
—
ideally
in
the
form
of
a
plant-based
green
waste
compost
—
to
its
surface,
said
Lynda
Deeks,
senior
research
fellow
in
soil
science
at
Cranfield
University
in
the
UK.
“Over
time
it
will
actually
be
incorporated
into
the
soil
and
so
increase
organic
matter.”

Biological
activity
in
the
earth
lessens
in
extreme
heat

Soil
moisture
is
also
important
for
the
underground
animal
kingdom.

Oxfam:
Acute
hunger
has
surged
in
climate
hotspots

“When
it
gets
so
dry
and
so
hot,
microorganisms
stop
their
activity,”
said
Nicole
Wellbrock,
a
soil
expert
from
the
Thünen
Institute
for
Forest
Ecosystems,
northeast
of
Berlin.
Without
the
input
of
organisms
like
the
nematode,
for
example,
she
said
the
nutrient
cycling
system
—
which
gives
plants
what
they
need
to
grow
—
slows.

And
it’s
not
just
microscopic
life.
“When
it
becomes
dry,
earthworms
naturally
go
into
a
state
called
estivation
—
they
effectively
go
to
sleep,”
said
Roy
Nielsen,
a
soil
ecologist
based
at
the
James
Hutton
Institute
in
Dundee,
Scotland.
Earthworms
then
stop
adding
organic
matter
and
aerating
the
soil
which
also
reduces
the
capacity
for
water
drainage.

Bringing
trees
back
to
farmland

Vasconez
Navas
of
the
University
of
Hamburg
says
we
should
“look
back
at
nature”
to
help
ecosystems
and
soils
to
regenerate
after
long
periods
of
stress.
One
nature-inspired
solution
is
agroforestry,
which
sees
trees
planted
among
traditional
cropland.

Wellbrock
of
the
Thünen
Institute
said
trees
generally
don’t
coexist
with
farmers’ fields
in
places
like
Germany.
“In
the
past,
they
were
actually
removed
as
part
of
the
agricultural
reforms,
because
of
course
that
was
arable
land,
and
[farmers]
favored
large,
uniform
areas,”
she
said.

Trees
don’t
only
help
control
erosion
and
evaporation
and
create
shade,
they
can
also
help
revitalize
drought-damaged
soils.

Certain
tree
species,
known
as
fertilizer
trees,
take
nitrogen
from
the
air
and
deposit
it
in
the
soil
through
their
roots
and
falling
leaves.
This
helps
farmers
improve
soil
fertility
with
a
low-cost
alternative
to
industrial
fertilizers.
In
Malawi,
Zambia,
Burkina
Faso
and
other
countries
in
sub-Saharan
Africa,
these
trees
are
helping
to
double
or
triple
the
yields
of
maize,
a
key
food
staple.

Low-tech
solutions
and
inspiration
from
ancient
civilizations

In
rural
areas
of
Tanzania
and
Kenya,
village
communities
are
using
a
low-tech
method
to
fight
desertification.

Their
technique
involves
digging
semicircular
depressions,
known
as
“bunds,” into
the
ground
which
collect
water
when
it
rains,
preventing
it
from
evaporating
quickly
from
the
scorched
soil.
Grass
seeds
are
then
sown
into
these
bunds
which,
as
they
germinate,
limit
soil
erosion
and
lower
the
ground
temperature.

New
study
debunks
theory
that
climate
change
is
biggest
reason
for
Pak
floods

A
growing,
global
community
of
conservationists
are
looking
to
the
past
for
solutions
by
restoring
terraces
among
neglected
farmlands.
Terraces
date
back
to
the
Bronze
Age
and
can
be
found
in
sites
such
as
Machu
Picchu
in
Peru.
Their
successive
sloped
planes
—
resembling
steps
cut
into
the
earth
—
limit
soil
erosion
by
preventing
runoff.
This
form
of
agriculture,
which
failed
to
compete
large-scale
cultivation
during
the
20th
century,
is
now
making
a
comeback
in
places
like
Italy
and
Japan.

While
a
range
of
options
exist
for
helping
to
ensure
soil
productivity,
the
variety
of
ecosystems,
soil
composition
and
range
of
conditions
means
there’s
no
panacea
for
optimal
soil
health.
Particularly
in
the
face
of
climate
change.

That
said,
one
of
the
best
strategies
for
ensuring
soil
can
deal
with
weather
extremes
is
to
aim
for
minimum
disturbance,
said
UK
expert
Deeks.
Organisms
in
the
earth
help
create
pathways
that
glue
earth
together
while
opening
pore
spaces
for
water
and
air,
key
for
ensuring
it
can
absorb
rain.
“The
less
we
do
to
the
soil,
the
better,”
she
said.

Source: DW