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