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What if it were possible to grow more grass on half the water? Is that even possible?
By far the best way to structure soil is through carbon sequestration.
Note: This is a great way to prepare for a drought.
However, 1.1" of moisture is required to get the process started.
Call 1-888-588-3139 to speak to a soil health consultant
Email us at info@ag-usa.net
Check this out! We have an application for every budget
Read the following article and let it inspire you with the possibilities
Dr. Christine Jones has written an exceptional
article which was published in the March, 2015
issue of AcresUSA.
This article does a great job of explaining how
carbon sequestration, the secretion of sugars
into the soil by plant roots, is the absolute
best method of creating wonderful, nutrient
dense topsoil.
This topsoil that works like a sponge to grab onto and hold moisture until it is needed. Here is her article. Enjoy!
To
the pressing worldwide challenge of restoring
soil carbon and rebuilding topsoil, the
Australian soil ecologist Dr. Christine Jones
offers an accessible, revolutionary perspective
for improving landscape health and farm
productivity.
For several decades Jones has helped innovative farmers and ranchers implement regenerative agricultural systems that provide remarkable benefits for biodiversity, carbon sequestration, nutrient cycling, water management and productivity.
The following article is reprinted from the March, 2015 edition, volume 45, #3 of AcresUSA Magazine
Dr. Christine Jones, Interviewed by Tracy Frisch
ACRES U.S.A. You’ve
written that the most meaningful indicator for
the health of the land and the long-term wealth
of a nation is whether soil is being formed or
lost. Yet there’s a widespread belief, actually
dogma, that the formation of soil is an
exceedingly slow process. Even some organic
researchers accept that idea. You describe the
formation of topsoil as being breathtakingly
rapid.
DR. CHRISTINE JONES.
People have confused the weathering of rock,
which is a very, very slow process, with the
building of topsoil, which is altogether
different. Most of the ingredients for new
topsoil come from the atmosphere — carbon,
hydrogen, oxygen and nitrogen.
ACRES U.S.A. Why
have many soil scientists denied the phenomenon
of rapid soil-building?
JONES.
Because they do their research in places where
it’s not happening, where the carbon is running
down and the soils are deteriorating. We need to
measure carbon on farms where soil-building is
occurring and see what the farmers and ranchers
are doing to make that happen.
.
ACRES U.S.A. The process of fixing
carbon in the soil seems to be the crux of your
work. You describe a cycle with carbon in three
phases: as a gas, a liquid and a solid.
JONES.
The issue we’re facing is that too much of the
carbon that was once in a solid phase in the
soil has become a gas. That could be dangerous
for the human species. Climate change is just
one aspect. Food security, the nutrient density
of food and the water-holding capacity of the
soil are also very potent reasons for keeping
carbon in a solid phase in the soil.
ACRES U.S.A. Your
term “liquid carbon” is such a brilliant phrase.
It has really helped me conceptualize the carbon
cycle. What do you mean by it?
JONES. Liquid
carbon is basically dissolved sugar.
Sugars are formed in plant chloroplasts during
photosynthesis. Some of the sugars are used for
growth and some are exuded into soil by plant
roots to support the microbes involved in
nutrient acquisition.
ACRES U.S.A. I remember bringing up the idea of leaky roots in a conversation with you and you laughed.
JONES.
At first people thought “leaky” roots were
defective. Exuding carbon into the soil seemed
such a silly thing for plants to do! Then it
became recognized that some of the exudates were
phenolic compounds with allelopathic effects,
important in plant defense. Of course we now
know that plant roots exude a vast array of
chemical substances, all based on carbon, to
signal to microbes and to other plants. But
perhaps the most significant finding, at least
from a human perspective, is that the
flow of liquid carbon to soil is the primary
pathway by which new topsoil is formed.
ACRES U.S.A. All
of which revolves around the concept of a
plant-microbial ridge?
JONES.
In order for carbon to “flow” to soil, there has
to be a partnership between plant roots and the
soil microbes that will receive that carbon.
Somewhere between 85 to 90 percent of the
nutrients plants require for healthy growth are
acquired via carbon exchange, that is, where
plant root exudates provide energy to microbes
in order to obtain minerals and trace elements
otherwise unavailable. We inadvertently blow the
microbial bridge in conventional farming with
high rates of synthetic fertilizers or with
fungicides or other biocides.
ACRES U.S.A. Are
you observing an increased awareness of the
significance of biological processes?
JONES.
There is a lot more energy generated through
biological processes than through the burning of
fossil fuels. Most life-forms obtain their
energy either directly or indirectly from the
sun, via the process of photosynthesis. Plants
are what we call autotrophs. That is, they feed
themselves by combining light energy with CO2 to
produce biochemical energy. As heterotrophs, we
obtain energy by eating plants or eating animals
that ate plants. In effect, we’re running on
light energy too. Even microbes in a compost
heap are obtaining energy by breaking down
organic materials originating from the process
of photosynthesis.
ACRES U.S.A. You
distinguish between organic matter formed by the
decomposition of manure, crop residues or other
carbonaceous materials — and humus — which is
generated via a building-up process. I think a
lot of times that is misunderstood.
JONES. It’s a really important distinction, but it’s often overlooked. In order to obtain the energy that is contained in cellulose, lignin, starches, oils, waxes or other compounds formed by plants, microbes have to break this material down — the same as we do when we digest starches or proteins or anything else of plant or animal origin. We breathe out more CO2 than we breathe in, because as we utilize the energy we obtain from the assimilation of food, our cells release CO2.
The decomposers in the soil are doing exactly
the same thing — breaking down organic materials
and releasing CO2. These processes are
catabolic. Conversely, the formation of humus is
an anabolic process, that is, a building-up
process. Rather than sugar being the end point,
sugar is the start point. Soil microbes use
sugars to create complex, stable forms of
carbon, including humus.
ACRES U.S.A. How
would you define humus?
JONES.
Humus is an organo-mineral complex comprising
around 60 percent carbon, between 6 and 8
percent nitrogen, plus phosphorus and sulfur.
Humic molecules are linked to iron and aluminum
and many other soil minerals, forming an
intrinsic part of the soil matrix. Humus cannot
be “extracted” from soil any more than wood can
be “extracted” from a tree.
ACRES U.S.A. You
frequently mention mycorrhizal fungi in your
work. What makes them so special?
JONES. Much of the initial research into mycorrhizal fungi was related to the uptake of phosphorus. Phosphorus is a highly reactive element. As soon as there’s any free phosphorus floating around in the soil, including whatever we may add as fertilizer, it becomes fixed. In other words, it forms a chemical bond with another element like iron or aluminum or calcium, making it unavailable to plants. But certain bacteria produce an enzyme called phosphatase that can break that bond and release the phosphorus.
Once released, the phosphorus still has to be transported back to the plant, which is where mycorrhizal fungi come in. As our analytical techniques have become more sophisticated, we’ve realized that mycorrhizal fungi also transport a wide variety of other nutrients, including nitrogen, sulfur, potassium, calcium, magnesium, iron and essential trace elements such as zinc, boron, manganese and copper. In dry times they supply water.
Mycorrhizal fungi can extend quite a distance
from plant roots. They form networks between
plants and colonies of soil bacteria. Plants can
communicate with each other via messages sent
through these networks. Mycorrhizal fungi are
both the highway and the Internet of the soil.
ACRES U.S.A. How
can something so important be overlooked?
JONES.
Much of the agricultural research undertaken in
pots in glass houses is fundamentally flawed.
Soil is homogenized to remove background noise,
that is, to make the soil in all the pots
similar at the outset. The blending process
breaks up the hyphae of mycorrhizal fungi. In
some trials the soil is also sterilized to
eliminate any microbial activity that could
interfere with the treatment being assessed. And
often the soil has been stored for a long time
prior to the experiments, which means most of
the soil organisms have died. In such an
environment, plants are likely to respond to
applied fertilizer, as they have no other means
to obtain nutrients. Similarly with field
trials, if the soil has been cultivated or bare
fallowed, mycorrhizal fungi will not be there in
sufficient quantities for effective carbon flow
and nutrient acquisition. In healthy,
biologically active soils, we do not see a
response to synthetic nitrogen or phosphorus
fertilizers. If anything, the use of these is
counterproductive.
ACRES U.S.A. I’ve
learned from you that plants colonized by
mycorrhizal fungi can grow much more robustly
even though they’re giving away as much as half
of the sugars that they make in photosynthesis
through their roots.
JONES.
That’s correct.
ACRES U.S.A. So
we have this system characterized by abundance
and generosity, and that’s really different from
the way we are used to thinking about growing
crops.
JONES.
The point that’s often missed is that a
mycorrhizal plant photosynthesizes much faster than
a non-mycorrhizal plant of the same species
growing right next to it. The plant is able to
give half its energy away and still grow
stronger because of the symbiotic relationship
with the fungus. It doesn’t cost the plant
anything to photosynthesize faster. It’s just
using sunlight more efficiently. Remember,
plants are autotrophic.
ACRES U.S.A. And
sunlight is free.
JONES.
CO2 is free too. If
a plant photosynthesizes faster it’s going to
have higher sugar content and a higher Brix
level. Once Brix gets over 12, the plant is
largely resistant to insects and pathogens.
High-Brix plants have formed relationships with
soil microbes able to supply trace elements and
other nutrients that the plant needs for
self-defense, for its immune system. When plants
are able to produce high levels of
plant-protection compounds, the insects go
elsewhere.
ACRES U.S.A. We
tend to think that minerals in the soil are
scarce because most of them are not in a form
available to plants.
JONES. A soil test will only tell you what is available to plants by passive uptake. The other 97 percent of minerals — made available by microbes — will not show up on a standard test. By looking after the microbes in the soil we can increase the availability of a huge variety of minerals and trace elements — most of which are not even in fertilizers.
ACRES U.S.A.
We always hear the story about fields that were
continuously cropped or hayed for 30 years where
the soil is so exhausted that we have to add a
lot of nutrients or we can’t grow a thing.
JONES. The problem is that we interrupt carbon flow with the way we farm. Cultivating the soil and using chemical fertilizer and pesticides break up the mycorrhizal networks. If plants can obtain nitrogen or phosphorus easily, they will stop pumping carbon into the soil to support their microbial partners.
It’s taken a while for people to realize that plant root exudates are not only important for nutrient exchange, but also essential for the maintenance of topsoil. If carbon is not flowing to soil via the liquid carbon pathway, soil deteriorates.Carbon is needed for soil structure and water holding capacity as well as for feeding the microbes involved in nutrient acquisition.
When soil loses carbon, it becomes hard and compacted. The differences in infiltration and moisture retention between high and low carbon soils are dramatic. Planetary stocks of fresh water are declining alarmingly. More efficient water use is going to be absolutely critical to the survival of our species.
Making better use of water requires improved
soil structure — which in turn requires actively
aggregating soils. If aggregates are breaking
down faster than they’re forming, the
water-holding capacity of soil can only
deteriorate.
ACRES U.S.A. How
can we tell if a soil has good aggregation?
JONES Dig
a hole and take a handful of soil. Squeeze it
gently and release. If the soil is well
aggregated, it will look like a handful of peas.
If the soil remains in hard chunks that don’t
break easily into small lumps, then it isn’t
well aggregated.
ACRES U.S.A. What
processes are going on inside
of a soil aggregate?
JONES The aggregate is the fundamental unit of soil function. A great deal of biological activity takes place within aggregates. For the most part, this is fueled by liquid carbon. Most aggregates are connected to plant roots, often to very fine feeder roots, or to mycorrhizal networks unable to be detected with the naked eye.
Liquid carbon streams into the aggregates via these roots or fungal linkages, enabling the production of glues and gums that hold the soil particles together. If you gently lift a plant from healthy soil, you’ll find aggregates adhering to the roots. The moisture content is higher inside a soil aggregate than on the outside, and the partial pressure of oxygen is lower on the inside than on the outside. These important properties enable nitrogen-fixing bacteria to function.
When aggregates aren’t forming — because
of cultivating the soil or using chemicals or
having bare soil for six months or more with no
green plants —
crops are not able to obtain sufficient
nitrogen. The tendency is then to add fertilizer
nitrogen, exacerbating the situation. The
application of large quantities of inorganic
nitrogen interrupts carbon flow to soil, further
reducing aggregation.
ACRES U.S.A. It
sounds like a vicious cycle.
JONES Yes,
the more N applied, the more soil structure
deteriorates and ironically, the less N is
available to plants. You’ll
rarely see a nitrogen deficient plant in a
healthy natural ecosystem.
When I was driving home yesterday I noticed
yellow, nitrogen deficient pastures on many of
the dairy farms I passed. But in the area
between the fence and the road, where no
fertilizer had been used, the grasses were a
lovely dark green.
ACRES U.S.A. We
are familiar with Rhizobium bacteria and their
relationship with legumes. What should we know
about free-living nitrogen fixing bacteria?
JONES From
an agricultural perspective the most important
of the freeliving nitrogen-fixing bacteria are
associative diazotrophs — so-called because the
atmospheric nitrogen that they fix occurs
as di-nitrogen (N2) and associative because,
like mycorrhizal fungi, they require the
presence of a living plant for their carbon.
These bacteria live in close proximity to plant
roots or are linked to plant roots via the
mycorrhizal highway.
ACRES U.S.A. Isn’t
our knowledge of these organisms pretty recent?
JONES The reason we know so little about associative diazotrophs is that most cannot be cultured in the lab. This applies to most species of mycorrhizal fungi as well. As bio-molecular methods for detecting microbes in the soil become more sophisticated, we’re realizing there is a lot more life — and a lot more species — than we thought. It has become obvious that there are thousands of different types of bacteria and archaea that can fix nitrogen.
The Haber-Bosch process, by which we manufacture
nitrogen fertilizer, is a catalytic reaction
requiring enormous amounts of energy. Yet
microscopic bacteria in the rhizosphere or
within plant-associated aggregates can fix
nitrogen simply using light energy from the sun,
transformed to biochemical energy during
photosynthesis and channeled to soil by plant
roots.
ACRES U.S.A. I’m
a little confused because I understood that
there is a difference between mineral nitrogen
and organic nitrogen.
JONES That’s correct. Nitrogen fixing bacteria produce ammonia, a form of inorganic nitrogen, inside soil aggregates and rhizosheaths. Rhizosheaths are protective cylinders that form around plant roots. They’re basically a bunch of soil particles held together by plant root exudates. You can easily strip them off with your fingers.
Within these biologically active environments the ammonia is rapidly converted into an amino acid or incorporated into a humic polymer. These organic forms of nitrogen cannot be leached or volatilized. Amino acids can be transferred into plant roots by mycorrhizal fungi and joined together by the plant to form a complete protein.
On the other hand, inorganic nitrogen applied as fertilizer often ends up in plants as nitrate or nitrite, which can result in incomplete or “funny” protein. This becomes a problem in cattle if it turns up as high levels of blood urea nitrogen (BUN) or milk urea nitrogen (MUN).
Nitrates cause a range of metabolic disorders
including infertility, mastitis, laminitis and
liver dysfunction. There is also a strong link
between nitrate and cancer. In some places in
the United States it is not safe to drink the
water due to excessive nitrate levels. Milk can
also have nitrate levels above the safe drinking
standard, but people happily consume it, not
realizing it’s unhealthy.
ACRES U.S.A. These
are great points. How dependent is the world on
the application of synthetic nitrogen?
JONES Farmers around the world collectively spend about $100 billion per year on nitrogen fertilizer. I’m greatly inspired by the multi-species over crop revolution in the United States. Leading-edge farmers like Gabe Brown, Dave Brandt and Gail Fuller are showing it’s possible to maintain or even improve crop yields while winding back on fertilizer. These farmers are light years ahead of the science.
They’re building soil, improving the
infiltration of water, increasing water holding
capacity and getting fantastic yields. They have
fewer insects and less disease. The carbon and
water cycles are fairly humming on their farms.
ACRES U.S.A. I
want to get your recipe for transforming
terra-cotta tile into chocolate cake — that is,
turning hard, compacted soil into loose,
fragrant soil teeming with life.
JONES. There isn’t a “recipe” as such for maintaining soil aggregates (the starting point for chocolate cake). It’s really just a set of guiding principles. Soil becomes like a terra-cotta tile when aggregates break down. Hard, compacted soil sheds water. The amount of effective rainfall is dramatically reduced. It’s also much harder for plant roots to grow in poorly aggregated soil.
The first rule for turning this around is to keep the soil covered, preferably with living plants, all year round. In environments where the soil freezes, it’s still important to maintain soil cover with mulch or a frost-killed cover crop or better still, a frost-hardy cover that will begin to grow again as soon as spring arrives.
Microbes will go into a dormant phase over
winter and re-activate at the same time as the
plants. In regions with a hot, dry summer,
evaporation is enemy number one. Bare soil will
be significantly hotter and lose more moisture
than covered soil. Aggregates will break down
unless the soil is alive. Aggregation is
absolutely vital for moisture infiltration and
retention.
ACRES U.S.A. OK,
so that’s one.
JONES. Point two is to maximize diversity in both cover crops and cash crops. Aim for a good mix of broadleaf plants and grass-type plants and include as many different functional groups as possible. Diversity above ground will correlate with diversity below ground. Third, avoid or minimize the use of synthetic fertilizers, fungicides, insecticides and herbicides.
It’s a no-brainer that something designed to kill things is going to do just that. There are countless living things in soil that we don’t even have names for, let alone an understanding of their role in soil health. It’s nonsense to say biocides don’t damage soil! In Australia many farmers plant seeds treated with fungicide “just in case.” They’re actually preventing the plant from forming the beneficial associations that it needs in order to protect itself.
After a few weeks of crop growth, they will then apply a “preventative” fungicide, which also finds its way to the soil, inhibiting the soil fungi that are essential to crop nutrition and soil building. The irony is that plants are then unable to obtain the trace elements they need to fight fungal diseases. We see many examples of crops grown biologically that are rust-free, side-by-side with rust infected plants in neighboring fields where fungicides are being used.
There is an analogous situation with human
health. Not that long ago the cancer rate was
around one in 100. Now we’re pretty close to one
in two people being diagnosed with cancer. At
the current rate of increase, it won’t be long
before nearly every person will contract cancer
during their lifetimes. Cancer is also the
number one killer in dogs. Isn’t that telling us
something about toxins in the food chain? We’re
not only killing everything in the soil, we’re
also killing ourselves — and our companion
animals. Is that what we want for our future?
ACRES U.S.A. You
say it’s not just the toxins in our food that
are the problem, but the use of biocides —
chemicals that kill living organisms — which
reduce the nutrient content of food. And you
attribute that nutrient reduction to the
inhibition of the plant-microbial bridge.
JONES.
Spot on. If the plant-microbe bridge has been
blown, it’s not possible for us to obtain the
trace elements our bodies need in order to
prevent cancer —
and a range of other metabolic disorders. Cancer
is not a transmissible disease. It’s simply the
inability of our bodies to prevent abnormal
cells from replicating. To date, the response to
the cancer crisis has revolved around
constructing more oncology units, employing more
oncologists and undertaking more research. The
big breakthrough in cancer prevention will be in
changing the way we produce our food.
ACRES U.S.A. We
have plenty of evidence from meta-studies that
the nutrient content of produce grown
organically tends to be higher than produce
grown chemically. We also have documentation of
steep declines in nutrient content in a number
of foods over the last century.
JONES.
Yes, we’re getting a double whammy. We’re
ingesting chemical residues, but not the trace
elements and phytonutrients we need for an
effective immune response. Plants need trace
elements, like copper and zinc, to make these
phytonutrients. But the trace elements will not
be available in the absence of an intact
microbial bridge.
ACRES U.S.A. You’ve
talked about the pressure on farmers to have
tidy farms and uniformity in their fields. It
seems like one of the problems you’re
identifying is a faulty understanding of what it
means to farm well and to be a good farmer. What
are some of the qualities that farmers think
they should have that get in the way of building
healthy soil?
JONES. I must admit that in the early ’90s, when I first started going onto farms that were using holistic planned grazing, I was a bit shocked to see the number of weeds popping up. These weeds would have been sprayed under the former management regime, but the ranchers were saying, “Don’t worry. We have to pass through this weedy stage. If we spray weeds, we create bare ground and the weed seed that’s there means the weeds simply come back.”
There’s a saying, “the more you spray weeds, the more weeds there will be to spray.” It’s oh so true! Continually reverting to bare ground creates more problems than it solves. Those ranchers knew some weeds had deep roots that bring up nutrients. Leaving them there meant better quality plants would eventually be able to grow in the improved soil and replace the weeds. That is exactly what happened. Over the last 60 years we’ve tried — and failed — to control weeds with chemicals.
One of the exciting things about the multi-species cover crop revolution that’s underway in the United States is that the greater the variety of plant types you use, the more niches you fill and the less opportunities there are for weeds. Cover-crop enthusiasts are experimenting with 60 or 70 different species in their mixes. I see the trend to polyculture as the most significant breakthrough in the history of modern agriculture. Even so, the first time you see a multi-species cover or a cash crop grown with companion plants, you might think, “Wow, that looks untidy” because we’re not used to it. It takes a little while to realize that having all those different plants together is really beneficial.
Somehow we have to change the image of what a healthy field looks like so that when people see bare ground or a monoculture, they recognize it’s lacking — and that this is not a good thing.
ACRES U.S.A. What sort of response
are the cover crop pioneers receiving?
JONES. They’re seeing fantastic results. The trouble is they are not getting the accolades they deserve. This is slowly beginning to change. NRCS, in particular, are being exceptionally supportive of these leading edge farmers. Cover cropping is now generating a huge amount of interest.
Recently I visited Brendon Rockey, a young
potato farmer in the San Luis Valley of
Colorado. Brendon has increased irrigation
efficiency 20 percent through the use of cover
crops. There is increasing worldwide recognition
of the fact that multi-species cover crops
improve soil-water relationships.
ACRES U.S.A. Right,
another aspect of that abundance.
JONES. If there is a bare fallow between crops — or bare ground between horticultural plantings such as grapes — soil aggregates break down. As a result, water cannot infiltrate as quickly. It remains closer to the surface and evaporates more readily. Lack of aggregation also renders the soil more prone to wind and water erosion.
We have this fear that if we grow companion
plants or a cover crop, they’re going to use up
all the water and nutrients. We have to realize
that by supporting soil microbes, a diversity of
plants actually improves nutrient acquisition
and water retention.
ACRES U.S.A. In the
transition period from a chemically intensive
system where you don’t have a functioning
plant-microbial bridge,
what are some kinds of practices that farmers
can use?
JONES. Sometimes when farmers realize the importance of soil biology they immediately stop using fertilizers and chemicals. This is not necessarily a good thing. It takes time for soil microbial populations to re-establish. If the soil is dysfunctional, chances are the wheels will fall off when fertilizers are pulled. If there is a failure, farmers will revert back to what they know ... chemical agriculture.
You have to wind back slowly and accept that it’s going to take time to transition. The key to getting started is to experiment on small areas. It’s a matter of dipping a toe in the water. Include some clovers or peas with your wheat, or vetch with your corn — just on one part of the field.
This reduces the risk. When farmers see that they’ve gained rather than lost yield — and that the crop looks healthier — they will be inspired to try a larger area and a greater variety of companion plants next time. Another option is to plant a multi-species cover crop on part of the land that would normally be devoted to a cash crop.
You’re exceptionally lucky in the United States in that a lot of farmers are experimenting with cover crops now. Once the diversity ramps up, the ladybirds and lacewings and predatory wasps appear and the need for insecticides falls away. And after heavy rain, it’s obvious that water has infiltrated better in the parts of the field where the cover crops were.
Gradually the changes become an integral part of
farming — an exciting part, in fact.
Experimentation and adaptation become the norm,
rather than conformity. Confidence builds, as
ways to restore healthy topsoil become firsthand
knowledge.
ACRES U.S.A. What
about fertility?
JONES. It’s important to cut back on chemical fertilizers slowly. If you’ve been using loads of synthetic nitrogen, then free-living nitrogen-fixing bacteria won’t be abundant in your soil. An easy way to transition is to reduce the amount of nitrogen applied by around 20 percent the first year, another 30 percent the next and then another 30 percent the year after.
At the same time as reducing fertilizer inputs it’s absolutely vital to support soil biology with the presence of a wide diversity of plants for as much of the year as possible.
Another way to gradually reduce fertilizer inputs is to use foliar fertilizers rather than drilling fertilizer under the seed. Foliar-applied trace minerals can also help during transition. These can be tank-mixed with biology-friendly products such as vermi-liquid, compost extract, fish hydrolysate, milk or seaweed extract.
Whichever path you choose to support soil
biology, the overall aim is for soil function to
improve every year. The overuse of synthetic
fertilizers will have the opposite effect.
ACRES U.S.A. You
mentioned the longest-running field experiment
in North America that found that high nitrogen
depletes soil carbon?
JONES. The Morrow Plots are the oldest continuously cropped experimental fields in the United States. A team of University of Illinois researchers investigated how the fertilization regimes that were commenced in these plots in 1955 affected crop yields and soil carbon and organic nitrogen levels.
They discovered that the fields that had received the highest applications of nitrogen fertilizer had ended up with less soil carbon — and ironically less nitrogen — than the other fields.
The researchers concluded that adding nitrogen
fertilizer stimulated the kind of bacteria that
break down the carbon in the soil. The reason
there is less nitrogen in the soil even though
more has been applied is that carbon and
nitrogen are linked together in organic matter.
If carbon is decomposing, then the soil will
also be losing nitrogen. They decompose
together.
ACRES U.S.A. That’s
fascinating. Tell me about David Johnson and
what he is finding in his research at New Mexico
State University.
JONES. Dr. David Johnson is based in Las Cruces, south of Albuquerque. He has discovered that the ratio of fungi to bacteria in the soil is a more important factor for plant production than the amount of available nitrogen or phosphorus.
Sadly, in most of our agricultural soils, we have far more bacteria than fungi. The good news is that farmers use multi-species cover crops, companion crops, pasture cropping and other polycultures — and the ranchers who manage their perennial grasses with high density short duration grazing accompanied by appropriate rest periods — are moving their soils toward fungal dominance.
When you scoop up the soil, it has that lovely
composty, mushroomy sort of smell that indicates
good fungal levels. Oftentimes agricultural
soils have no smell or a smell that is a bit
sour. Fungi are important for soil carbon
sequestration as well as nutrient acquisition.
The formation of humus, a complex polymer,
requires several catalysts, including fungal
metabolites.
ACRES U.S.A. That
is a really interesting insight. I would like to
get some perspective on soil degradation. You’ve
written about how lush and green Australia’s
landscape was at the time of European settlement
in the early 1800s, land that’s now desertified.
How do your readers react?
JONES. They have a particularly hard time believing that the southern and southwestern parts of Australia supported green plants during our hot, dry summers. It’s fortunate that some of the first European settlers kept journals. George Augustus Robinson, who was the Chief Protector of Aborigines, kept a daily journal for several years.
Robinson was a keen observer. He made sketches
of the landscape as well as describing it. In
summertime when it was over 100 degrees and
without rain for months on end, Robinson noted
green grass and carpets of wildflowers
everywhere he looked. Sadly, we don’t know what
many of these plants were because we no longer
have wildflowers in some of the colors he
recorded.
ACRES U.S.A. Could
you reconstruct what happened to destroy all
this lush, diverse vegetation?
JONES. European colonists brought boatloads of sheep which rapidly multiplied. In England you could have sheep in continual contact with the grass and it didn’t matter greatly because it nearly always rained. Australian weather tends to oscillate between drought and flooding rain and the English weren’t used to that. By the late 1800s there were many millions of sheep in Australia, grazing the grasslands down to bare earth in the dry periods.
When it rained, the unprotected soil washed away. The river systems and wetlands filled with sediment. We’re now farming on subsoil. We’ve lost around 2 to 3 feet of topsoil across the whole country. The original soil was so well aggregated that aboriginal people could dig in it with their bare hands.
The first Europeans to arrive in Australia talked about two feet of black “vegetable mold” that covered the soil surface. Today our soils are mostly light-colored. The use of color to describe soils only came into being after the carbon-rich topsoil had blown or washed away. It’s not an uncommon story.
Just about every so-called civilized, developed country in the world has lost topsoil by one means or another. In the States you had your Dust Bowl, created by tillage. Restoring the health of agricultural soils will require more than learning how to minimize soil losses. We need to learn how to build new topsoil, and we need to learn how to do it quickly.
ACRES U.S.A. I
read that in Australia, using the so-called best
management practices of stubble retention and
minimal tillage, wheat production results in the
loss of 7 kilograms of soil for every kilogram
of wheat harvested. Is it still that bad?
JONES.
Yes, probably worse. I have documented evidence
of 20 tons of soil per hectare per year being
lost through wind erosion. The average wheat
yield in Australia is very low, around 1 ton per
hectare. We lose massive amounts of soil to
achieve it. The current situation is not
sustainable.
ACRES U.S.A. How
much of Australia’s farmland would have to
increase soil carbon to offset your country’s
carbon emissions?
JONES.
It would require only half a percent increase in
soil carbon on 2 percent of our agricultural
land to sequester all Australia’s CO2 emissions.
Our emissions are low in relation to our land
area because we have a relatively small
population.
ACRES U.S.A. Do
you have any idea worldwide how much farmland
would have to be managed differently to increase
soil carbon sufficiently to reverse global
climate change or offset greenhouse gases?
JONES. Agriculture is the major land use across the globe. According to the FAO there are around 1.5 billion hectares of cropland and another 3.5 billion hectares of grazing land. Currently much of that land is losing carbon.
No doubt there will be — and indeed there already have been — endless arguments about how much carbon can be sequestered in soil. In my view it’s not a matter of how much but how many. The focus needs to be on transforming every farm that’s currently a net carbon source into a net carbon sink.
If all farmland sequestered more carbon than it was losing, atmospheric CO2 levels would fall at the same time as farm productivity and watershed function improved. This would solve the vast majority of our food production, environmental and human health problems.
I’m disappointed to see that articles are still being published in internationally recognized peer-reviewed soil science journals — as recently as 2014 — downplaying the potential for carbon sequestration in agricultural soils. Predictably, these articles fail to mention plant roots, liquid carbon or mycorrhizal fungi.
Many scientists have confused themselves — and the general public — by assuming soil carbon sequestration occurs as a result of the decomposition of organic matter such as crop residues. In so doing, they have overlooked the major pathway for the restoration of topsoil. Activating the liquid carbon pathway requires that photosynthetic capacity be optimized.
There are many and varied ways to achieve this.
I have enormous respect for the farmers and
ranchers who have done what the experts say
can’t be done. If we have a future, it will be
largely due to the courage and determination of
these individuals.
ACRES U.S.A. You
initiated the Australian Soil Carbon
Accreditation Scheme (ASCAS). I’m quite
impressed that one person started something like
that.
JONES. I launched ASCAS in 2007 out of frustration that the federal government wasn’t doing anything to reward innovation in land management. I wanted to demonstrate that leading edge farmers could build carbon in their soils and be financially rewarded for doing so. But my attempts were blocked at every level, including being subjected to public ridicule.
I suspect much of the resistance stemmed from the fact that Australia was importing over $40 billion worth of farm chemicals and policy-makers saw that as a big business. They realized that in order to build soil carbon, farmers would need to reduce chemical use. There were other issues too.
Australia ratified the Kyoto Protocol nine months after the launch of ASCAS. Under Kyoto Protocols, the issuance of carbon credits requires adherence to the 100 year rule, which basically means that any payment for soil carbon must be registered on the land title and the money refunded if for any reason the carbon levels fall over the ensuing 100 years.
Then there’s the additionality rule, which
states farmers cannot be paid for changes in
land management that they would have made
anyway, or that result in higher profits.
ACRES U.S.A. You
said this story has a good ending.
JONES.
Despite the roadblocks, I felt it was important
that soil restoration pioneers be recognized.
Late last year we decided to discard the
original ASCAS model and start afresh. On March
19, 2015, almost eight years to the day after we
launched the ASCAS in 2007, our patron Rhonda
Willson will present 11 Soil Restoration
Leadership Awards at a farming forum in Dongara,
Western Australia. It’s a fitting conclusion
that these awards be presented in the
International Year of Soils.
ACRES U.S.A. What
changes did your Soil Restoration Leaders make
in order to improve soil function?
JONES. The agricultural region of Western Australia experiences an extremely hot, dry summer. Winters are cool and moist, although not as moist as many farmers would like. Innovative ranchers have been planting summer active grasses at the end of winter when there is sufficient moisture for germination, despite ‘expert’ opinion that it’s too hot and dry in summer for anything to grow. Perennial grasses have incredibly deep root systems and form mycorrhizal associations that help them survive.
The grasses soon create their own microclimate.
It’s an absolute delight to see these patches of
green in an otherwise parched landscape. It
helps us understand how the countryside
encountered by the first European settlers was
able to remain green over the summer.
ACRES U.S.A. At
the People’s Climate March in New York City, a
large contingent of vegan activists carried
signs blaming cattle as a major cause of global
warming. What are your thoughts on targeting
ruminants for greenhouse gas emissions?
JONES. There were more ruminants on the planet 200 years ago than there are now, but we’ve gone from freeranging herds to animals in confinement. That changes everything.
Firstly, we’re growing feed for these animals using fossil-fuel intensive methods and secondly, confinement feeding creates a disconnect between ruminants and methanotrophs. Methanotrophic bacteria use methane as their sole energy source. They live in a wide variety of habitats, including surface soils. If a cow has her head down eating grass, the methane she breathes out is rapidly metabolized by methanotrophs.
There’s an analogous situation with termites. Termites produce methane during enteric fermentation, as happens in the rumen of a cow. But due to the presence of methanotrophic bacteria, methane levels around a termite mound are actually lower than in the general atmosphere.
In
nature, everything is in balance. After the
disastrous Deepwater Horizon oil spill in the
Gulf of Mexico, the ocean was bubbling with not
only oil, but also methane. To the astonishment
of scientists monitoring the spill, populations
of methanotrophic bacteria exploded and consumed
an estimated 220,000 metric tons of methane gas,
bringing levels back to normal.
ACRES U.S.A. When
we talk about the consequences of the increased
extreme weather associated with climate change,
like devastating floods and droughts, all too
often we neglect to consider how better
land management can reduce their impacts.
JONES. With weather events becoming more extreme our farming systems need to be more resilient. Again, this is where having carbon sequestered in soil to maintain aggregate stability and improve infiltration is vitally important.
If we look at flooding on the Mississippi, for example, we see that the mean maximum and mean minimum water levels from the early 1800s to the present show an increasing perturbation since the dust bowl era of the 1930s. That is, the highs are becoming higher — floods are more severe — and the lows are getting lower — the river doesn’t ‘run’ as much as it used to.
This boom-bust situation is due to inappropriate land management. If soil is in good condition, water infiltrates rapidly and is held in the soil profile. Some of this water is used for plant production and some will move downward through the soil to replenish the transmissive aquifers that feed springs and small streams, enabling year-round, moderated baseflow to river systems.
If groundcover is poor and soil water-holding
capacity is low, rapid run-off not only leads to
flooding in lower landscape positions, but also
takes a lot of topsoil with it. These days it’s
not just soil, but a heap of chemicals too —
which end up in the Gulf of Mexico.
ACRES U.S.A. Causing
the Dead Zone?
JONES.
Yes. The consequences are enormous. And when the
flood is over, the river level drops because the
transmissive aquifers haven’t been recharged.
ACRES U.S.A. Is
adding compost to the soil sufficient to turn
things around?
JONES. Compost is certainly a fantastic product, but compost alone is not enough. It will eventually decompose, releasing CO2. However, the application of compost to appropriately grazed pastures or polyculture crops can increase plant growth and photosynthetic rate, resulting in more liquid carbon flowing to soils.
Diverse microbial populations — particularly fungi — supported by the compost, can aid in humification, improving soil structure, water-holding capacity and nutrient availabilities.
On large agricultural holdings such as we have in many parts of Australia, it is not economically viable to spread compost. However, compost extract, which is simply the chemical signature of compost, can prove highly beneficial.
The use of natural plant or seaweed extracts as biostimulants is a relatively new but rapidly expanding area of R&D and farmer-adoption worldwide. The advantage of biostimulants is that they function at very low rates of application — milliliters per hectare — as opposed to a product such as compost which needs to be applied in tons per hectare.
These products stimulate soil biota and enhance
plant root function. The proliferation of roots
is quite obvious when you dig in the soil. There
can also be rapid improvements in soil structure.
For more information about Dr. Christine Jones visit www.amazingcarbon.com.
MycorrPlus is incredibly successful, more
than any other method we know of, for accomplishing
the things Dr Jones talks about in the above
article.
Dr. Jones says that the formation of topsoil can be breathtakingly rapid. She explains that the reason for this is that most of the ingredients for new topsoil come from the atmosphere, including carbon, hydrogen, oxygen and nitrogen. Plants utilize these to produce liquid carbon, which they then exude into the soil through their roots in order to feed soil microbes. It is this flow of liquid carbon (sugars) into the soil that is the primary means by which rich topsoil is formed.
MycorrPlus provides a host of nutrients, including a rich supply of the trace minerals found in ocean water. These nutrients supply the soil with what it needs so that it can supply plants with the energy they need to reach their maximum potential.
MycorrPlus provides 70+ beneficial bacteria plus
mycorrhizal fungi.
These micro-organisms help to create balance in the soil. Balance
is everything! The
balance created causes the soil to possess a high energy level.
When this energy is made available to plants, it energizes them
to sequester sugars to feed the micro-organisms in the soil.
As the micro-organisms are nurtured and fed by the plant, they in turn make nutrients and energy available to the plant. This enables the plant to sequester even more sugars into the soil. This relationship between microbes and plant result in plants being able to attain their optimum potential.
The Best Way to Form Topsoil
Many scientists have confused themselves — and the general public — by assuming that building soil carbon and the making of topsoil occurs as a result of the decomposition of organic matter such as crop residues.
In stark contrast, Dr. Jones points out that most of the elements needed to create topsoil are found in the atmosphere and that the creation of new soil centers around carbon. Compost may help, but it is simply not the best way to create topsoil.
A plant can acquire between 85 to 90 percent of the building materials it needs from the air to create liquid carbon. The rest of the nutrients are provided from the soil. Soil microbes use this liquid carbon as an energy source to help them convert tied up nutrients into available plant food. In the process, the sugars emitted by the roots act as gums and glues to create complex soil structure, which includes stable forms of carbon and humus.
New topsoil is rapidly created in this environment. Once MycorrPlus is activated with at least 1.1” of moisture and a soil temperature above 45 degrees, almost immediately plants begin to secrete liquid carbon into the soil, and it is only a matter of weeks before new soil begins to form.
This is superior to results seen by using a bio stimulant, including
natural plant or seaweed extracts. MycorrPlus contains every
micro and macro nutrient needed by the plant, plus fungi and over 70
species of bacteria that help the soil to convert nutrients tied
up in the soil into
plant food.
Carbon is needed for soil structuring and water holding. As liquid carbon streams into the aggregates via the roots or fungal linkages, it enables the production of glues and gums that hold soil particles together.
Establishing a good soil structure enables nitrogen-fixing bacteria to function. You will rarely see a nitrogen deficient plant in a healthy natural ecosystem. Ammonia that is fixed from the air is rapidly converted into an amino acid or incorporated into a humic polymer. These organic forms of nitrogen cannot be leached or volatilized.
With rapid carbon sequestering, the growth rate of plants can quickly increase. That is the power of properly functioning soil.
Dr. Jones states that, when
transitioning between a chemically intensive system and one
dependent on a functioning plant-microbial bridge, there
needs to be a transition period of 3 years or more, reducing
nitrogen fertilizer by 20% the first year, 30% the next year and 30%
the third year.
Dr. Jones mentions that
foliar applications of trace minerals can help in the transition
from a chemical program. For higher dollar crops, MycorrPlus-F
can be applied as a foliar application to meet this need.
As plants photosynthesizes
faster, they are going to have higher sugar content and a higher
Brix level. Once Brix gets over 12, the plant is largely resistant
to insects and pathogens.
As Dr. Jones pointed out,
if plants can obtain phosphorus and potash easily, they will stop
pumping carbon into the soil to support their microbial partners.
This interruption of the carbon flow to the soil reduces aggregation
and the forming of new topsoil.
However, grain plant like corn or wheat will likely need extra nitrogen.
As Dr. Jones stated,
including some clovers or peas with your wheat or some vetch with
your corn is another way of supplying the soil with extra organic
nitrogen. As is mentioned in her article, in biologically active
soils, Dr. Jones found the use of NPK to be
counterproductive.
Remember that a soil test
can only tell you what is available to plants by passive uptake of
inorganic nutrients. The other 97 percent of minerals, those made
available by microbes, will not show up on a standard soil test.
By nurturing the aerobic
microbes in the soil, we can increase the availability of a huge
variety of minerals and trace elements — most of which are not
contained in fertilizers.
For most applications, just 32 to 64 ounces per acre
is all that is needed.
This is how soil can be built very cost
effectively.