We hear a lot about climate change and carbon dioxide.
What can farmers do about it?
'A lot,' says Austra,lian soil scientist, Dr. Christine Jones.
' and get better crops as a result.'
It's all about getting light energy,
transforming it to biochemical energy,
getting that biochemical energy into the soil,
to drive the soil ecosystem to make nutrients available
Well, the reason that carbon is important
is because all living things contain carbon
so as things live and die, they give up their carbon
and then something else lives and takes up that carbon.
I guess what we're talking about with climate changes,
we're talking about that cycle getting out of balance
So, for thousands of years it's been in balance...
the atmosphere and the plants, and the soil,
and all the living creatures.
But in modern times people have dug up
and burned fossil fuels and exposed soil for farming.
In fact, over a third of the carbon
added to the atmosphere since 1850
has come from deforestation
and exposing, and oxidizing the rich carbon deposits in our topsoil.
U.S. soil scientist Dr. Elaine Ingham says,
'We can put it back though.'
'And in a way so that much of it will stay.'
So, carbon sequestration - we're talking about putting CO2
from the atmosphere back into the soil
in a form that's not going to be lost.
How do we do this?
The same way nature did in the first place.
We've got to be photosynthesizing.
So, we've got to be growing plants in that soil...
So CO2 and sunlight will be bound back into sugar structures.
As those sugars go down into the root system,
Picking up all the nitrogen phosphorus sulfur magnesium calcium
from the soil.
Building that plant material - the plants are putting
exudates out into the soil,
'cakes and cookies' out into the soil,
and the bacteria and fungi utilize that material
and build the organic matter back in the soil once again.
Those sugar water exudates are the key.
This photo shows liquid carbon flowing from a plant root above,
along a fungal hypha or two,
to feed the fungus below.
In exchange for that carbon,
soil microbes, including fungi,
bring water or micro nutrients to the roots,
causing the plant to release more carbon.
In order to build that soil carbon,
you have to be looking after the microbial
or supporting the microbial communities in the soil
that join all the little carbon atoms together
to form humors polymers.
It can't grow as well unless those microbes are there.
They won't have as many trace elements in them
if those microbes aren't there,
and when the plants don't have those trace elements in them,
they become vulnerable to insect attack and fungal attack,
pathogens of all kinds.
Finally, we're now seeing the light as it is
and realizing that we are like farmers.
And that what we need to do is
to harvest as much sunlight energy as possible,
by having as much green leaf as possible.
Therefore, as much of the year as possible.
Because photosynthesis drives the whole system...
soil should always be covered with plants,
either crop plants or cover crops.
Farmers here in the United States
started experimenting with two-way covers,
and then five-way covers, and then 10-way covers,
and now they're sort of aiming for 20-way covers.
In other words, 20 different varieties of plants in a cover crop.
And realizing that the more diverse they make the cover crop,
the faster they can build soil.
And the more, less reliant they are on any chemicals at all.
Farmers are finding that building soil biodiversity
builds plant health.
And they're finding they don't have to use any synthetic fertilizers anymore,
they don't have to use pesticides,
they don't have to use insecticides.
They not only are they producing food that's higher in nutrients,
but it's also lower in toxic chemicals.
And they're taking co2 out of the atmosphere
and storing it in soils.
We also want resilience in our fields.
Carbon builds a good clumpy soil structure,
holding on to rainwater.
And the other thing is how quickly when the rain does absorb...
how quickly does it evaporate.
So when it gets into the soil, we want it to stay there.
So we want to have an aggregate send us all,
aggregates the little lumps like pea show clumps in the soil
that have a much higher moisture content
on the inside of the aggregate than on the outside.
And we see the greatest increases in carbon sequestration,
through what I call 'the liquid carbon pathway' -
when it's being
fixed in and green leaves transfer
powder through the plants excuted by
roots into microbial communities in the
soil and forming aggregates and leading
to the process of unification which is
the holy grail for soil to have an
increase in humans in the soil so our
job as dr. Ingham says is to farm so we
are working with nature
so don't till could we have a list of
those farmers that are no-till or zero
till and really let people know that
they're the ones doing the work and as
dr. Jones says this kind of farming is a
win for everyone if we can take more of
the carbon that's in the atmosphere and
store it in our soil and our soils and
our food production systems are going to
be more resilient but we could produce
the same meal with much higher quality
with much lower cost and building soil
at the same time
I think the fundamental shift in
thinking that we have to make is that
farming is about harvesting light
through the process of photosynthesis
we're going to change light energy to
biochemical energy and then that
biochemical energy becomes our plants
our animals so you know through the
carbon compounds that are made by that
process we are fundamentally light
farmers and when we make that
realization then the sky's the limit.