The world beneath our feet.
[Music]
i was in the office of a guy who helps
people build healthy soils
and he asked if i wanted to look at some
through a microscope
of course i did eyes to the eyepiece is
a twiddle of the focus knob
and it came alive with much jostling
amidst the autumnal
a roundish blob went speeding across my
field of view
i let out an involuntary gasp i wanted
to follow it but i didn’t know how
and the rest as they say is history
i’m an eco-social worker and science
communicator i love soil microbes
and all the wonderful things they do for
us whether it be growing healthy plants
regenerating our soils or entertaining
me with their delightful antics
if you’ve never heard of microbes before
you’re not alone
they are so small that you can’t see
them with the naked eye
and let’s face it it’s pretty difficult
to be passionate
or even interested in something that you
can’t see
but by the end of my story today
i hope that perhaps you’ll be willing to
share
a little about the importance of
microbes with others i pinch myself
that i can share my passion and show
people
how microbes can impact in everyone’s
lives
soil without microbes
is just dirt and soil does so
much more than holding plants up while
they grow
we face environmental economic social
and health challenges that can
all be traced back to degraded soils
the national soil advocate major general
michael jeffrey
discussed soils of the role of soil
in human health climate change and
surprisingly to me national security
the mention of microbes peppered
throughout various con
conversations left me wanting to know
more
i said about exploring
microbes are so small that they are
invisible to the naked eye
and yet they’re all around inside and
out if you think about us
then about 10 of our cells
are human the other 90
are microbial and of the ones that are
in our guts
about a third of those also live
in the soil what does that say about our
diet
that we do indeed eat dirt and if that’s
not weird enough
then on a small suburban block like mine
there’s the roughly the equivalent in
microbial
biomass of several
kangaroos living underground
there are more microbes in a teaspoon of
healthy soil
than there are people living on this
earth
let me repeat more microbes
in a teaspoon of soil than people living
on earth
i learned that in the 1980s dr elaine
ingham was part of a team that
discovered that plants growing in soil
containing
bacteria fungi protozoa and
nematodes thrived when compared to soils
plants growing in soil that lacked even
one of those organisms
who loves nematodes
some of you haven’t heard of nematodes
well nematodes are similar to earthworms
but they’re a lot smaller and they can
wiggle a lot
nematodes have different mouthpieces
depending on what they like to eat
some like bacteria some like fungi
some like other nematodes and some like
the occasional root
you might have been on the receiving end
of nematodes when they destroyed your
tomato
crops but rest assured
most nematodes are beneficial and doing
wonderful things in your soil
i learnt that healthy plants carbon
sequestration
and good soil structure are directly
related to the quality of the food we
eat
the air we breathe and the water we
drink
and they’re all directly dependent on
you guessed it soil microbes
when soil is alive with microbes
its structure is characterized by these
coarsely shaped crumbly carbon rich
aggregates that keep it fluffy
and make it capable of absorbing and
releasing water
like a sponge the levels of carbon are
significant because
one gram of carbon can hold
roughly eight grams of water
i wonder what that means for
us how much water can our soils hold
what might that that’s yours and mine
what that might
might that mean for our summer watering
regime or our next water bill
microbes play a key role in building
those carbon rich aggregates
the bacteria ooze a gooey slime that
glues together the smallest of soil
particles
to make them into brick like clumps and
fungi grow
long sticky strands that act like mortar
to tie those bricks together
so we end up with the bricks and water
of the underground
we might think of these as being homes
for microbes
safe places places where they
can vary the temperature or control the
air flow
and without these bacterially built
bricks or the fungally formed mortar
soil structure is poor and
compaction is common
without these we can end up with dust
bowls
sorry without the the microbes we can
end up with dust bowls clogging our
lungs
and rivers running brown as the topsoil
is washed downstream
is your soil structure fit for purpose
are there lots of places carbon rich
spaces
to hold water nutrients
talking of nutrients we have our
stomachs inside of us
to digest our food to provide our
nutrients but i learnt that plants
plants outsource their stomachs to the
soil
the soil is their stomach
bacteria and fungi collect the nutrients
and hold them in their bodies a bit like
bags of fertilizer
now we all know that bags of fertilizer
are fine
but not much good to the plants when
they’re in the shed
we need a way to get the nutrients to
the plants
a bit like fertilizer spreaders protozoa
single-celled organisms and nematodes
some of the world’s smallest animals
work like fertilizer like like spreaders
in that they eat the bacteria and fungi
keeping the nutrients that they need for
themselves for their own well-being
and excreting the rest in a
plant-available form
they’re clever spreaders though in that
the nutrients excreted in this way
enhance the flavor of the food and the
nutrient density of the food
and make the plants inedible to pests
and resistant to disease
our soils are broken because we’ve
decimated populations of these nutrient
cycling
aggregate building microbes through our
agricultural
and and gardening practices
i love soil microbes
should you could you care about microbes
if you think of them as being the
willing powerful workers in your soil
that protect the plants from pests and
disease
allowing them to flourish and saving you
money in the process
it’s likely you want to get to know them
better
david attenborough says that no one will
protect
what they don’t care about and no one
will care about what they’ve never
experienced most people have never
experienced
or seen their own soil microbes
and if we are to protect and care for
microbes in order to regenerate our
soils
we need opportunities to get to see our
own
we need to be talking to our kids
about microbes and soil health
we need to be encouraging our children
to care for our soils
in order to protect them for their
future
and of those of many generations to come
our jostling wiggly sticky hairy
bustling soil microbes
that are too small to be seen with the
naked eye
that i have a weighty presence in our
soil
and are so plentiful to be almost beyond
counting
keep us alive and living in a wonderful
world
be audacious make opportunities to get
to see your own and
when you get to welcome these tiny
underground strangers
listen out for your gasp of delight
thank you
[Music]
you