-
We hear a lot about climate change
and carbon dioxide.
-
What can farmers do about it?
-
'A lot,' says Australian 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 change is,
-
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 humus 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.
-
Not Synced
And they're taking co2
out of the atmosphere
-
Not Synced
and storing it in soils.
-
Not Synced
We also want resilience in our fields.
-
Not Synced
Carbon builds
a good clumpy soil structure,
-
Not Synced
holding on to rainwater.
-
Not Synced
And the other thing is how quickly
when the rain does absorb...
-
Not Synced
how quickly does it evaporate.
-
Not Synced
So when it gets into the soil,
we want it to stay there.
-
Not Synced
So we want to have
an aggregate send us all,
-
Not Synced
aggregates the little lumps
like pea show clumps in the soil
-
Not Synced
that have a much higher moisture content
-
Not Synced
on the inside of the aggregate
than on the outside.
-
Not Synced
And we see the greatest increases
in carbon sequestration,
-
Not Synced
through what I call
'the liquid carbon pathway' -
-
Not Synced
when it's being fixed in green leaves,
-
Not Synced
transfer powder through the plants
-
Not Synced
executed by roots
into microbial communities in the soil,
-
Not Synced
and forming aggregates,
-
Not Synced
and leading to the process of unification,
-
Not Synced
which is the 'holy grail' for soil,
-
Not Synced
to have an increase in humus in the soil.
-
Not Synced
So our job, as Dr. Ingham says, is to farm
-
Not Synced
so we are working with nature.
-
Not Synced
So, don't till. Could we have
a list of those farmers
-
Not Synced
that are no-till or zero till
-
Not Synced
and really let people know that
-
Not Synced
they're the ones doing the work?
-
Not Synced
And, as Dr. Jones says, this kind
of farming is a win for everyone.
-
Not Synced
If we can take more of the carbon
that's in the atmosphere
-
Not Synced
and store it in our soil,
-
Not Synced
and our soils
and our food production systems
-
Not Synced
are going to be more resilient.
-
Not Synced
but we could produce the same meal
with much higher quality,
-
Not Synced
with much lower cost,
-
Not Synced
and building soil at the same time.
-
Not Synced
I think the fundamental shift
in thinking that we have to make
-
Not Synced
is that farming
is about harvesting light.
-
Not Synced
Through the process of photosynthesis
-
Not Synced
we're going to change light energy
to biochemical energy,
-
Not Synced
and then that biochemical energy
becomes our plants, our animals.
-
Not Synced
So, you know,
through the carbon compounds
-
Not Synced
that are made by that process.
-
Not Synced
We are fundamentally light farmers
-
Not Synced
and when we make that realization
then the sky's the limit.