[ Inaudible talking ]
>> I'm going to thank you all for standing by.
Participants will be in a listen only mode until the question and answer session.
At that time if you'd like [background noise] to ask a question please press star then one.
Today's call is being recorded.
If there are any objections you may disconnect at this time.
I would now like to turn the call over to Mr. David Lamm.
Sir, you may begin.
>> Thank you, and I want to welcome everybody to the fourth webinar
in the Mississippi River Basin Healthy Watershed Initiative where we're focusing on those things
that we can do to improve soil quality and have a positive impact on the nutrient loading
that happens to be going down the Mississippi River.
Today's topic we're going to be talking about the role of soil biology
and improving soil quality and hopefully you all have received a copy of an email
that has a little flyer like that in there.
And just for future references when you see that you know there's a webinar coming up
and you can just say, "Click here" to join the webinar, and that'll take you right in
and you walk through the walk down the steps there and you ought
to be able to get into the webinar.
All of them are at 2 o'clock Eastern Standard time on Wednesday.
Our next one will be on August the 10th.
We have made arrangements to get CCA, continuing education units credits,
but it's up to you to apply for them.
What you have to do is go on right where -- just follow the red arrow over there on the top
of your screen, you should see a hand out button.
If you mouse over that it should have hand out show up and when you click
on it you'll get a screen that looks like this that has a whole list of documents
that Dr. Nichols has provided for you to download
that will help further your understanding of soil biology and the work that she's been doing,
and the significance and the role that it plays in improving soil quality
and nutrient availability and nutrient cycling.
Also you'll be able to click on there.
You need to check it, too.
Put a little check mark in there if you want to download it, where it says,
"Documentation for certified crop advisors."
You click on that and you download that and then you're responsible to put your name,
put your CCA number there, and then sign it and you can get it back to here
at the East National Technology Support Center in two different ways.
One, you can fax it and make sure you put attention to Holli Kuykendall,
or you can scan that document after you sign it, and email it to Holli.Kuykendall@gnb.usda.gov.
And you need to get that back within the next two or three days so we can process these
and then what we do is basically we look at what you send in, we link and provide the CCA folks
with a listing of printed -- those who have participated that we get from the webinar folks
and they can verify that you participated in the webinar.
If you want to ask questions there's two ways you can do it.
We have all the folks are on mute right now, but at the end of the session you can do it audibly.
You can press star, zero, and you'll get the operator and she'll introduce you
and you can give her you -- your name and then she'll bring you in,
allow you to ask your question that way.
Or the other thing you can do is, again, at the top you have a menu list there,
you click on where it says Q and A, that stands for questions and answers.
You just type in your question and it'll go into a queue
and then we'll answer those as they come in.
So again, two ways one if you want to -- want us to hear your voice, and the second one
if you want to type in a question.
That one might be kind of handy as you're going through, you know,
Dr. Nichols will bring something up and midway through the presentation you want
to remember it you can type your question in at any point during the presentation,
but we will be only answering questions at the completion of the presentation.
Now let me introduce Dr. Nichols.
I'm really excited about this topic because I know all of us
out there meet the soil conservationist series qualification and had a bunch of soils classes
when we were back in college and we all learned about the physical,
chemical and biological aspects of soil but somehow during our careers when we checked
out the soils class we left out the biological part and we focus solely
on the chemical and the physical.
Throughout my career and the way I was trained and brought
up in the Midwest the biological aspect was never emphasized
and I think that's really been the key to this whole issue of soil biology.
We're talking about increasing organic matter ,
understanding the important role the biology the soil has in this and its significance
in maintaining sustainable soils for sustainable agriculture.
Anyway Dr. Nichols was raised in Minnesota basically on a corn, soy bean farm.
She received her Bachelor Science Degree from the University of Minnesota.
So she's in the Big Ten there.
She got her Master's from West Virginia University which shows how daring she is.
She was telling earlier how she went there sight unseen
to get educated in microbiology out there.
She earned her PhD from the University of Maryland and she's been on the cutting edge
of this whole idea of soil biology with the a focus on mycorrhizal fungi relationships
with the plants and get involved with investigations on farming land,
and you can read the rest, but I think we have probably one of the leading speakers
on this topic that we could have got.
So I hope that you'll sit back and enjoy this.
And, Chris, I'm going to turn it over to you,
and we'll go up here and bring up your presentation.
>> Thanks a lot, David, and thank you all for attending and for the committee
for inviting me to give this presentation.
I'm really excited about having this opportunity and I love to talk about soil,
so you may end up having to cut me off at some point in time and just say, "Okay,
that's enough," because I could talk about soil for hours,
and especially looking at soil biology.
I think David made a very good point in the fact that a lot of times through our soil
of education we learn about the physical and the chemical sides of soils and that's a lot
of the analysis that we do when we look at soils, but often we don't look that much
at the soil biology and the interaction that that has.
And so hopefully I'll give you some ideas on the roles of some of the organisms that are
in the soil and what you can do to help manage the system so that you're able to get more
of these organisms in your soil and what some
of those impacts are going to have on the whole system.
When I was first asked to do this I sort of started off and I was trying to focus
on the Mississippi River area and then I realized that a lot
of these concepts are very general.
There are going to be some things that I believe when you focus
on soil biology you may be adjusting or doing some of the methods a little bit differently
or utilizing some different crops, but the concept is the same.
It's going to work wherever you are.
A lot of times I've been in various areas of the country talking to farmers and a lot
of times I'll say, "I hear all of these excuses why your system doesn't work.
It's too cold, it's too hot, it's too wet, it's too dry.
You know, it's never going to be the perfect season."
As David said, I was raised on a corn soybean farm and I told my dad
that if he ever had the perfect season he'd probably die of a heart attack,
because it's never going to be perfect but what we're trying to do is we're trying to come
up with a system that's going to help you manage whatever it is
that you have, and whatever conditions occur.
When you focus on the soil biology you can see by the huge diversity of numbers and diversity
of activity that you have a lot of redundancy of function which means that whether it's too cold,
or too hot, or too dry, or too wet, there are going to be some organisms in the soil
that are going to be working and they're going to be able to provide some of these benefits
to the environment that you're growing your plants in.
And so, you know, the quote on the bottom I really believe in that civilization sort
of rests on the soil and they survive as long as the soil is not exhausted, and we are, I think,
rapidly heading to a point where there's going to be a lot of issues with the soil
and hopefully we can stop it so that the soil is not completely exhausted,
because we need to maintain that resource.
I believe it's the most precious resource we have.
We're talking a lot these days about energy and things like that
and we can find other sources to produce energy.
We can find other sources to alleviate some of the depletions
that we have in some of our resources.
But the soil resource is not a resource that we can find alternatives for.
We can't find the alternatives that are going to allow us to be able
to produce enough food to feed our growing population.
So I just want to set the stage with that.
I reviewed a couple of the earlier speakers and so a lot
of this information you probably heard from some of the other speakers.
I'll try not to be too redundant but I'll also emphasize again, some of the important topics
that exist out there with soil biology.
So to begin with I want you to think of the soil as the heart of the system.
It basically is what's going to be connecting above ground and the below ground activity.
So the organisms that are above ground and the organisms
that are below ground are connected via the soil environment.
It's also the ultimate recycler primarily carbon and nitrogen and oxygen but other number
of different elements as well that is necessary for the plants to be able to grow.
It drives the physical and the chemical and the biological processes
that hold this system all together, and it is estimated that the value
of the services provided by the soil that includes soil life and its foundation.
Soils for building, soil for growing crops, the biological activity, the organisms from soil is
over $20 trillion on a global basis per year.
But just the activity of the organisms themselves in the soil, fixing nitrogen,
cycling phosphorus, providing the nutrients to the plants
from that soil environment those organisms are valuable extremely valuable
and if that's maybe their value can be well over one and a half trillion dollars.
So we're looking at a resource that definitely has a very strong economic value not just a
social and environmental value.
And the biggest part of the soil and the thing that we can see the most
and identify what makes a good soil versus a bad soil is that dark, rich,
organic matter that may be in the soil and it's really a very small amount
of the total soil weight but this is where almost all
of the functions that occur in the soil happen.
That organic matter is primarily negatively charged, but it binds both cat ions and ions,
and if you can see from the figure below you have this activity that's moving the nutrients
that are moving from soil colloids into the soil solution and then into the plant root,
and a lot of that activity is driven by the root exiting
which are feeding the organisms that are in the soil.
So you have nutrients that bind chemically with the soil minerals
but then you have mechanisms via soil organisms to release those nutrients
and provide them for plant growth.
So as soil organic matter increases you can also increase the amount of water holding capacity.
The organic matter like I said it's a very small amount of the weight of the soil
but it's a large amount of the volume and that volume versus weight allows it to act
like a sponge and it will be able to absorb water.
And it's an area that stock piles a huge amount of the amount of carbon that is actually
in the atmosphere of planet earth.
So it's this huge stock pile in the storage of carbon and that carbon is very important.
This organic matter is very important and the carbon in it is very important,
because it's the primary food source either directly or indirectly
for most of the organisms in the soil.
And when you're looking at trying to grow
and maintain those organisms the two things I want you to keep in mind for this presentation
and the things we're focusing on are the basic needs of the organisms in the soil
and that the first basic need just like any other organism
that these soil creatures have is food and then the secondary need is habitat.
And so what we're trying to do is we're trying to create an environment in the soil
that has the maximum amount of food and the best habitat to maintain these organisms.
So we can start seeing the functions increase and improve
in our soil systems and improve soil quality.
This is sort of a rough diagram of again the concept of soil organic matter
and how much soil organic matter there is.
Again like I said soil organic matter can be one to six percent of the amount
of the total soil mass and that organic matter is primarily composed of the stable fraction --
the humid fraction that gives that dark richness to the soil
and then you has the more readily decomposable, the plant material those types of things
that are going to be in soil environment and the smaller fraction
of that is actually the organisms themselves.
The bodies of the organisms are considered part of the total soil organic matter.
The most dominant as far as weight is concerned organism is the soil fungi
and then the most dominant as far as the number
of individual organisms is actually the bacteria.
So in this case we're also looking at parameters that involve size.
So the reason that the amounts are divided up the way they are is not just
because of the numbers of the organisms, but also how big they are.
So you may have very few animals in the soil the micro arthropods and algae and protozoa
and organisms like that but they actually can make up quite a bit
of the soil mass because of their large size.
[ Silence ]
Now in looking at the soil rhizosphere, this is the zone that is right around the plant roots
and I think that we're going to see more and more that basically, I'd sort of phrase it
as this that the root of the problem is the root of the solution.
If we have soil roots in our environment it's going to solve the problems that we have
in production in agriculture and a lot of times we look at various problems
and we're actually not looking at the problem.
So we call them problems but they're actually symptoms of a greater problem,
and that greater problem is a lack of carbon and a lack of microbial activity in the soil.
Most of the carbon that's made by the plant during the growing season is actually
transmitted into the roots and then out into the soil to feed those organisms that are going
to be living around the rhizosphere.
So having a living root growing
in that environment can have a really big impact on the soil environment itself.
It impacts the soil structure, it impacts nutrient cycling activity
and this environment is where those organisms are directly connected
with above ground management.
So even though these tiny organisms may not have any contact
with the soil surface they are definitely impacted by that environment
through how we manage systems and how that impacts the roots and the amount
of carbon that's given to the soil environment through the roots.
The soil livestock is very diverse - it's a very integrated system.
It's a mixture of microscopic organisms.
You have molds and gophers and earthworms and spiders and beetles and all of those types
of things that we're able to see, and then you have all
of the microorganisms that are in the soil.
You have soil fungi and you can see sometimes the representatives of fungi on the surface
in mushroom but those other organisms that you have can be microscopic.
So it's very hard to see them and it's very hard to think that they are present
in as high of numbers as they are.
It's said that in a handful of healthy soil there are more organism than the number
of people that ever lived on planet earth.
So we have billions upon billions of microorganisms in that soil environment
that are interacting with the environment that they're living in but they're also acting
in such a way that they interact with each other in a variety of ways.
It's going to allow for some of these processes to occur and that's also very important
because a lot of times a particular type
of organism can't really do its full activity alone.
It relies upon other organisms to interact with it.
The biology of the soil is the organic or living component of the soil.
That heart -- the soil is the heart of the system.
What keeps that heart beating is the activity of these organisms.
Again like I said there are billions of them and they represent millions of different species.
The total weight of the amount of organisms that are in the soil
in a cultivated soil you can get it down to about five thousand pounds per acre
in a very healthy soil you can have four times that amount, and its difficulty to be able to --
think one of the reasons why we don't always look at the soil biology in our systems
in often times you can come up with standardized tests that it's fairly easy to look at some
of the chemical interactions and some of the physical interactions, but it's not so easy
to look at some of the biological interactions because these organisms are so small.
You can have a very different community and very different activity that's occurring
at one spot and, you know, different activities that's occurring at another spot
and that's going to vary a lot depending on the amount of water or nutrients
or physical properties of the soil.
You're going to have these micro spaces in the soil environment
that may house one type of community.
It may be even though a lot of the soil surrounding it is very dry
and the micro environment that's created that is fairly wet.
And so it houses a different community then some of the other environments that are in the soil.
So a lot of times when I'm doing soil sampling one of the problems that I run
into from a research stand point is the fact that I'll take samples in a thirty
by sixty foot plot which is about the smallest plot that can be set up.
So I'll be taking samples from that plot and I'll take the samples across the plot
and what ends up happening is in one sample -- I'll take about 15 samples across the plot
and in sample number one I may hit upon a large community of a particular organism
that I'm looking for and then in the sample two
or sample number three there isn't that same large community.
So it's very hard to interpret exactly what's happening when you can't get a very good count
on the number of organism that are in that whole plot,
because there's so much variation between samples.
And we're continuing to work from a research stand point on finding ways --
better ways to sample and better ways to analyze the samples
so that we can understand that biology even more.
These organisms as I said there's a lot of inter connection between them
because they can't do everything by themselves and many of you --
possibly most of you have seen this graphic on the soil food web, and the main thing I want
to point out with this graphic is that the first tropic level
that first food source is from photosynthetic activity.
It's from either the residue from the plants or from the exits from the plant roots.
And so in order to be able to feed that whole entire food web you need to have plants
that are growing or you need to have a lot of residue in the system.
You need to incorporate something that's going to be putting that photosynthetic carbon
into the soil as much as possible.
Again, kind of to give you a little bit of an idea of what we're looking at here.
We're mostly going to be looking at the microscopic organisms
which the largest ones are one two hundredth of an inch.
The smallest ones are one two thousands of an inch.
So we're looking at things that are very small by comparison but again play a huge role one
by the numbers of them that are out there and also, by the activity that those organisms do.
So now to kind of take a look at those individual growths of organisms,
the bacteria can number in the billions in soil and there's only about, you know --
there's only about 11,000 different species that may be in a gram of cultivated soil.
When you're looking at a under disturbed native type soil or --
you know, relatively high plant production type of soil you can be looking
at over 500,000 species of bacteria that may exist in there.
So there's a lot that happens above ground that impacts the diversity
of these organisms that are below ground.
The bacteria primarily feed on organic matter
and it's the organic matter that is easy to break down.
So it's some of the labile organic matter.
As they're consuming that organic matter they're also converting a lot
of that organic matter into that humus fraction.
So you have some that the organisms are going to take up but just again
like all organisms they take in food and they give off waste, and you're also in this type
of a system you have both predator and prey at the same time.
So we're going to talk about a lot of the organisms that are actually going to feed off
of these other organisms and that are what's going to allow for the cycling of nitrogen
and the cycling of carbon and phosphorus and those types of activities
in that soil environment to have that nutrient cycling occurring.
The bacteria can do some things in the soil where they can help to decompose pesticides,
they can help to decompose some other chemicals that are in the soil and break that down
and again they're very important in the nitrogen cycle.
One of their important roles in the nitrogen cycle is they act as a food source
for larger organisms and by being consumed by larger organisms the nitrogen that's
in their bodies is released into the soil environment.
You also have a lot of asymbiotic and symbiotic bacteria
such as rhizobium there would be some added bacteria that are associated with legumes
that actually can take atmospheric nitrogen and convert it
to a plant available form of nitrogen.
So again they are very important in providing the amount of nitrogen and that amount
of nitrogen is now become pretty close to the amount of nitrogen that we fix synthetically,
and we're going to talk about what's been happening with nitrogen use efficiency
and the need to keep producing more synthetic nitrogen to feed our systems
and how that impacts grain production.
Now the fungi come in two main types.
They come in the saprophytic type that feed on the organic matter
that it's more difficult to fight down.
There are actually more of the residue decomposers
and that is an extremely important role in our systems
because otherwise we basically would be buried in residue if we didn't have these Saprophytes
but the organism that I spend a lot of time looking at and that I see
that play a really important role in our agricultural systems when you look
at nutrient cycling are the mutualistic fungi.
Primarily they're trading phosphorus for photosynthetic carbon but they are able
to trade a number of different nutrients.
They can also act as assistance in some of the biological cycles that are going on.
They can connect one plant to another plant which can be very important
for nutrient flow and carbon flow in a system.
They also are very important to the physical structure of the soil
to creating a stable soil environment
and one of the ways they do this is by formation of soil aggregates.
The fungal hyphae will act like a net to accumulate soil minerals and organic matter
and other organisms to form these balls or pallets in the soil
that are the soil aggregates, and the soil aggregates as we'll talk
about a little bit later as well, have a very important role in what's happening in the soil
and how that impacts plant growth, as well as,
the various ecosystem services that the soil provides.
But these organisms are, their bodies are primarily these fine threads or strands
of fungal hyphae and those threads are very fragile.
They're very easily harmed by plowing or disturbance to the soil environment
and for the mutualistic fungi they need to maintain that connection with the living plant
because they aren't decomposers like the saprophytic fungi.
So they can't find a new food source.
They need to be connected to a living plant in order to be able
to get their food and grow and survive.
The mutualistic fungi the primary group
of mutualistic fungi are the vesicular mycorrhizal fungi,
and literally that means arbor, like Arbor Day, it's tree shaped --
so they're tree shaped and mycorrhizal means myco is fungus and rhiza is for root.
So they're tree shaped fungal root fungi, and what that means is they are very good
if you look at the picture you're able to see how the fungal hyphae goes
out into the soil beyond that depletion zone that the plant will have.
The plants are very good at taking up the nutrients that are right next to the roots
or can come in contact with the root hairs and they deplete the nutrients
that are there very readily, but then they need a mechanism to grow out further into the soil
and this may only be one to two inches out into the soil.
It doesn't seem like a lot but it actually can make a very huge difference on the amount
of nutrients and the amount of soil that the plant can access.
Again the fungal hyphae when they're growing out into the soil they'll sort of branch
out into tree shaped like structures, and what that allows --
it allows them to have a greater surface area to volume ratio and basically what
that means is the fungal hyphae can contact more soil with a smaller strand.
So there's less carbon that's needed to form the small strands then there are the large strands
and so there's greater volume that's in the large strand.
These fungi are generalists they will colonize a number of different hosts.
They actually penetrate into the root cell through the root cell wall
and then they'll form these other branch structures and that allows them
to maximize the contact they have with the plasma membrane and the cell,
and they can very easily then transfer the nutrients via that contact.
So both of these mechanisms are allowing them to maximize their activity for a minimum amount
of carbon use, and this is why they're very important
to the plants that are growing in the system.
If you don't have a lot of these fungi in the soil environment what we've seen is often times
that can stretch plants or it can require the plants to need more synthetic nutrients
because this is the primary mechanism that the plants evolved with over time
to acquire the nutrients in the soil.
If we take that away we have to replace it with something and that's one
of the things that's happened in our ergonomic systems and the way we manage them by again,
doing a lot of tillage in our systems by having none complex rotations
so you may have corn soybean two crop rotation or continuous corn
which is only a one crop rotation.
So you're not giving them a lot of different kinds of food.
That's what a rotation does is it provides some different kinds of foods
to feed these organisms again, because they're connected directly to a living plant.
If there isn't a plant growing -- whenever there isn't a plant growing you don't have these
mycorrhizal fungi growing.
So if you have fallow in your rotation system which is common the further west that you go,
you're not going to have a lot of these fungi.
And again what they do is around that rhizophere they're very good at making --
they engineer their own environment that assists them
in maximizing the amount of nutrients that they can get.
They've helped to form those soil aggregates
and in those soil aggregates they attract different bacteria
and those bacteria will do some of the activity to help to release phosphorus
from the soil mineral, they'll do activity where they're fixing nitrogen
and that is providing those nutrients that the fungi can then take
out and deliver back to the plant.
This is a pay as you go type system.
The plant will not give carbon to the fungus if the fungus does not give nutrients to the plant
and again in our modern cultural systems what we've done is we've given the plant a lot
of nutrients very early in the growing season which puts a lot
of nutrients in that rhizosphere environment.
So the plants don't need to have the relationship with the fungi at this time.
And so they'll basically not give carbon to the fungi and eventually the fungi will start
to die off and they'll give up on being able to get carbon from the plant,
and that's what's reducing the numbers of these fungi in the system in addition with the levels
of disturbance and the amount of plant growth that we have.
So all of these factors that we're doing through background management are impacting how much
of this fungal growth we can actually get and how efficient our systems are actually being.
This is some microscope pictures so you can get a real visual representation
of what's happening.
The top picture at the top -- left hand picture shows the fungal hyphae extending
out of the corn roots and you can see all of those really fine threads that are out there
and it basically can -- if you look at the amount of carbon that was in the roots
and the amount of carbon that's in that fungal hyphae, you can double or triple the amount
of access that you have to the soil, but you're only doing that at maybe a half
to a quarter of the amount of carbon.
So again, it's a very efficient way of working in a system and the left right hand picture --
or the right hand lower picture shows the our vascular that are inside the roots
and as you get more of that tree shaped or bushy structure the more you have in contact --
more hyphae you have in contact with the plasma membrane of the root cell that allows you
to have this very efficient type of exchange.
So again these organisms evolved with the first land plants.
For plants to be able to grow on land and get the water and nutrients they needed,
they needed to be associated with these fungi.
There's strong evidence of this in the fossil record.
They were able to see that these plants did really utilize the roots.
In fact the first land plants utilized the roots primarily for a anchoring structure
so that they could start to grow up as opposed -- and get into larger sizes as opposed to,
algae that are in aquatic systems that they originally evolved
from which are mostly unicellular.
So they're now able to become multi cellular organisms and grow up because they're anchored
in a spot but anchored in a spot makes it harder for you to get nutrients.
And so they had to form this relationship in order to be able
to get the nutrients they needed from the soil.
[ Silence ]
The next organisms we're going to take a look at are the Nematodes.
And I wanted to bring up the nematodes because nematodes generally get a bad rap.
They're mostly considered bad, they're pathogenic.
They're horrible to have in your system.
You have to put in pesticides and exterminate them as much as possible from the system.
Most of the nematode species are actually none pathogenic.
They're organisms that actually primarily feed on fungi and bacteria
and that can be very important because they're very good at helping
to control the populations of some organisms.
The idea of the diversity of these organisms like I said you can be both predator and prey
at the same time, and by being prey it means that there's one organism that helps
to keep your population in check.
The reason that we have a lot of diseases in our modern cultural systems is
because we're growing primarily one type of plant that is supporting the life
of very particular types of organisms in the soil and those numbers of organisms
because they're the only ones getting fed their population grows out of control
but if you maintain the diversity of the system those different organisms are going to make sure
that one population doesn't go out of control.
It's very important to have these organisms and by consuming the bacteria they're able
to consume the bacteria in very large numbers and so it's very easy for them
to release some nitrogen from the system because the nitrogen again that's locked up in the body
of the bacteria the bacteria is consumed by the nematodes and some of that nitrogen comes
out of the nematode as waste and then that nitrogen when it comes out of the nematode is
in a plant available form because it's been broken down.
So it's an inorganic form instead of the organic form that it was in when it was a part
of the body and when it's in that inorganic form it now can be taken up by the plant.
So it's a way of cycling nitrogen to the system.
It goes from an inorganic form into the bodies of the bacteria and then bacteria are consumed
and it's released from the bacteria into an inorganic form and that can go back
out to the plant and we can reorder it into an organic form again and keep on going
through the cycle unlike the bacteria where you have billions of them in a gram of soil
for the nematode you may have only ten to twenty individuals,
but again, their size is much large.
So they're able to those ten to twenty individuals can represent about ten percent
of the microbial bio mass whereas bacteria will represent about 30% of the microbial biomass.
So in a lot of the cases the organisms below ground size and numbers matter and you want
to make sure that if you're small in size you have a very large number,
so that you can actually impact the entire system.
The picture that's at the bottom is one that I like to show
because it's actually a fungus that is trapping a nematode.
The fungal hyphae those threads that are the body of the fungi it forms a loop or a lasso,
and then it will give off some compounds that will attract the nematode.
That basically it's telling the nematode there's food there and the nematode will come toward it
and when it wiggles its way into that lasso the fungi will actually cause cytoplasm to get
into the cells that are making up that lasso and those cells will swell
and then it traps the nematode there
and then the fungi will release enzymes that decompose that nematode.
This is a way of the predator and prey relationship and only do you have the nematodes
that can still the fungi and the bacteria to keep their numbers in check,
but you also have fungi that can consume nematodes to keep their numbers in check.
So again, you have less pathogenic type of relationships in a healthy soil then you do
in a non-healthy soil and it's because of all of this activity of these organisms.
They're helping to keep populations under control.
[ Silence ]
The last microorganism, I'm not going to discuss some of the Mezzo
and the Macro organisms very much in the system because I want to focus in on some
of these very small organisms that we don't see very much and we don't pay a lot
of attention to, but for the last minutes I'm going to focus on the Protozoa
and they include a wide diversity of types of organisms many of them
that you've probably seen or heard about.
You have the Paramecium, you have Amoebas.
They basically move by flowing their cellular contents from one part of their body
to the other part of their body, so that they can move through small spaces
and actually move in the soil environment.
Most of the ciliates and the flagellates actually have hairs that help them to move.
The organism that's in the upper right is sort of a cross between the two.
It has cilia and you can see their fuzzy on the front part of the organism but mouth parts are
and that cilia what that does is --
instead of helping the organism to move it actually causes bacteria
to flow towards the mouth of this particular protozoa so it makes sure
that it gets its food source flowing to it but it actually moves more like an amoeba.
It moves by moving its cellular contents or it's called pseudopodia.
They stick out part of their body like a leg or an arm and move that
and that allows them to move forward.
It's an anchor that they can move the rest of the body too and again
like the nematode the protozoa are larger in size so there's fewer in number in a gram
of soil and they consume the bacteria.
So again they're an important part of the nitrogen cycle because they're eating bacteria
and pooping out nitrogen in a plant available form in an inorganic form when they break
down the bodies of those bacteria.
Oh sorry I have one more group I apologize.
One more group the Micro Arthropods and these are the microscopic insects
and they are the decomposers and the shredders.
They're very good at breaking large pieces of organic matter down into smaller pieces
that then the bacteria can consume.
In an agricultural system they are very easily harmed by tillage practices and pesticides.
The insecticides that utilize inter ergonomic systems
to control large macroscopic insects also affect these micro arthropods these microscopic insects
which means that every time you spray an insecticide not only are you getting rid of all
of the larger macroscopic insects whether they are good or bad you're also getting rid
of the micro arthropods whether they are good or bad and that can affect the amount of food
that the bacteria can have because there's nobody to shred that organic matter
into the small pieces that bacteria can eat.
So organic matter decomposition relies more on the activity of saprophytic fungi then it does
on this combination of micro arthropods and bacteria.
So now you're limiting those various populations as well
and this gives you a relative size of things.
So we've got a thin particle and then you've got one
of these micro arthropods these microscopic mice that's the biggest thing on the picture
and then you can hardly see the nematode that's there.
That's a microscopic worm.
From a scale standpoint if you were looking at bacteria you basically would see the --
instead of a mite it would be a nematode that would be that size
and then the bacteria would be something you could barely see on the screen.
So [background noise] again, there's a huge variation in size in these microscopic organisms
but they all play some different roles in helping that system work.
There's also earthworms that are in the system and this is the only macroscopic organism
that I'm going to talk about and the reason I'm bringing out earthworms is they form
and you can see it in the lower right hand corner they form these tunnels in the soil
and they leave behind surfaces soil cast that contain a huge amount of nitrogen and phosphorus
and organic matter and that helps to feed some of the other organisms.
In fact along that tunnel that is growing through the soil you'll have bacteria
that will just line the surface of that tunnel, because as the earthworm grows
through the soil it leaves behind --
on the surface of the body it has some lubricating polysaccharides.
It leaves behind those polysaccharides which then becomes food source for bacteria and fungi.
So it's a way of the fungi and the bacteria getting deeper into the soil
and having a continuous amount of food source
because they can't travel very far given their limited size.
So the bottom line with what you want to do the first thing that you really want to focus in on
for the system is to replace iron tillage
with biological tillage with the activity of earthworms.
Replace it with the activity of plant roots that are --
you have some large tap roots that can help break up layers of compaction.
The fine roots that will come from grass plants that will spread out in further
in the soil and create smaller channel.
But they're still creating tunnels and reducing compaction in soil environment and I see
as the primary thing to do even though the greatest need that a plant has is for food
because a lot of times if you have a lot of compaction and you have an iron tilled system --
a conventionally tilled system you'll have layers of compaction that are right
under that soil layer and that means that you can't get the plant roots
and you can get those organisms to grow with the plant roots very far in the soil environment
and so you aren't really being able to support a lot of good diversity of organism growth.
They may have food because you have a plant growing but their habitat is so disturbed
and so broken up that it's hard for those organisms to even try and survive and to be able
to get to many of those food sources.
So again what you want to do is you want to build the amount of organisms that you have
in the soil and I want you to do cultivation but I don't want you
to do cultivation with a piece of metal equipment.
What you do cultivation with is you cultivate those organisms so they will do that cultivation
of the soil environment themselves and again what they need primarily is food.
They need to have a diverse crop rotation.
So you're feeding a different type of food source.
This is basically giving the soil environment proteins and fruits and vegetables and bread.
All of those things that the different organisms need to grow you're providing that into
that environment when you have a more diverse crop rotation and if you're
in a system you're working with producers that are in a system that because of equipment
and because of marketing needs they fixed them better to have a shorter rotation.
There are alternatives to improving that crop rotation by adding cover crops or switching it
up a little bit where maybe you'll grow a cover crop for part of the year
or you'll grow a hay crop for part of the year so that you've got something different that's
in that system that helps to provide that diversity.
You want to make sure that that food source is consistent.
The last thing you need are these organisms starving and Jim Hoorman brought up this topic.
He was talking about the fact that these organisms even here in North Dakota
which many people consider the end of the earth and a frozen wonder land even here
in North Dakota we can have microbial activity happening almost every day of the year and I say
that because we've done studies where we've looked at gas emission,
we've looked at CO2 emission, and nitrous oxide emission.
Gases that are produced by organisms that are growing in a soil environment
and we can measure those almost every day of the year.
So we're able to see the fact that organisms are growing,
and part of that is those microorganisms are creating those micro sites.
They're creating that little environment that they need to be able to continue growing.
They'll create the stable those aggregates that are part of their habitat.
They engineer their own homes in order to keep themselves in an environment
where they can maximize the amount of food that's available to them.
They can protect themselves; the bacteria that are in these environments are protected
from the nematodes and the micro arthropods and the protozoa so they're not consumed
at the same rate, and they're in an aggregate where there's organic matter available
to them that's locked inside that aggregate that they can consume
and that aggregate again is a protected environment where a lot of the changes
in temperature and changes in moisture that's the last places they'll get
to is inside that aggregate.
So you can have more stable temperatures and more stable water conditions moisture conditions
to maintain that activity for a longer period of time and what we do with a lot of our systems
when we don't include cover crops or perennial --
something that gives continuous cover what happens is we're basically feeding the organism
for short time -- if you're growing a short season grass like wheat for about two months
of the year and expecting those organisms to survive
until the next year when you're planting.
So we're feeding billions of creatures on about two months of carbon and expecting them
to survive for ten months and it's a system that over time doesn't work because you're continuing
to deplete the number of organisms that you have in your soil and again
if you cultivate these organisms you're going to increase the amount
of soil organic matter you have, you're going to improve the fertility of the system
because you're going to have better nutrients linked through all of these different types
of organisms and in the long run will increase the profitability for the producer
because there's less synthetic nutrients they need to add, less pesticides they need to add,
less maintenance and cost in creating a none compacted and growing environment
for the plant roots to be able to grow so you can get higher yield
and you're also creating an environment where you have less top soil loss to erosion,
whether it's wind or water erosion.
So you're creating a system that is automatically going
to be more profitable to the produce.
In the beginning in creating a lot of these systems
and making these system changes you may end up seeing yield decline.
It's very common as the system is transitioning from a system
that wasn't very biologically active to a system that's very biologically active
but at the same time you're reducing costs and so a lot of times when you're I guess trying
to sell these management changes to producers --
when I'm talking to producers a lot of times it's not just about what you make at the end
of the year when you sell your grain but it's about what your overall expenses were.
Your overall net profit was and that's what's going to be important in making sure
that people utilize these systems because you can reduce some of these costs.
Reduce the amount of passes that you have over the field and reduce the amount
of diesel fuel you use and like I said you reduce the cost of pesticides and the cost
of some of the synthetic nutrients and from an environmental standpoint you also get long term
sustainability of the system.
The way that we utilize a lot
of our agricultural systems right now we do different mechanisms in order
to try and make them sustainable.
We do terracing, we've done sustainable tillage.
We try and grow more crops.
We try and increase plant population.
All of these things that we're trying to do to help create a more sustainable system
but at the same time a number of the things that we're trying to do are actually not contributing
to long term sustainability of the system.
It's a very short term impact and what we need to do is introduce all of these tools
to create a system that's biologically active and going to be able
to provide these benefits and this is just a long list.
I'm not going to go through because we're going to touch on a lot of this stuff and have touched
on a lot of this stuff but these are the things as you can see there's a huge amount of things
that just putting carbon into that rhizosphere, increasing the amount root exudates
that you have can have on the health of the entire system and sustainability of the system
and when you do these things where you're changing the tillage type
and you're changing the plant diversity, adding these various components
and you don't have to add them all.
Just as you're adding some of these various components what you see is
that the math doesn't work anymore.
Two plus two does not equal four.
You can have two plus two equaling sixteen
because the effects are not adding they're multiplying each other and so you want
to be able to create these management systems that are actually going
to give more then they're going to take away and that's working with the background management
and reducing the amount of tillage.
Adding some crop diversity, adding cover crops, adding manure and compost,
working with the timing in which you make these changes, adding grazing as a way
of managing some of the forage that you have, some of the crop residues that you have,
making sure you maintain some crop residue in the environment.
All of these different things are going to have huge benefits to the system.
When you do tillage I talked about this with the fungal hyphae and this illustrates what happens.
So you do tillage and it breaks up the fungal hyphae and it's in strands and it exposes
that humus organic matter to the surface and what that humus organic matter is
on the surface it's actually exposed to the decomposing organism
and so it basically can get eaten up very fast
because the decomposing organisms what they do is they eat high carbon, low nitrogen material
and they eat it fast and the reason they do is because often times the protein
or what contains the most nitrogen is taken off of the field as the crop that you're growing
as the grain that you're growing and the residue that's left behind is very high in carbon
and low in nitrogen and that's very similar to that buried organic matter
that humid organic matter in molecular structure.
And so those decomposers that need to eat it fast so that there's not residue
that is increasing on the top of the soil
so that you're getting some residue decomposition they eat it very fast
and they'll eat the organic matter as well and then that just ends up getting burned off
into the atmosphere as CO2 and we've seen evidence of that as we've looked
at the historic loss of soil carbon.
So as we're looking at when we started applying tillage
to the soil system we rapidly reduced the amount of carbon that was in the soil
and we're trying to change some of that.
you can see starting around the 1970s when we had the oil crisis
and then we had the clean air act put into position and the clean water act put
in position those changed some of the ways that we manage
but that actually hasn't had a dramatic increase on the amount
of carbon that we have in the system.
So we want to increase that amount of soil carbon because we can see all the benefits
that come with water holding capacity and food from microbes and all of those different things
that come with having more organic matter in your system.
So we want to continue with this idea of reducing tillage but we also want
to find some other mechanisms that may allow us to increase the amount of organic matter we have
in our soil at an even faster rate and one of those is by adding crop residue
and there's a lot of question as to if residue is treasure or trash,
if it should be just taken off and maybe utilized as a biomass fuel source.
And you know there are issues with it for feeding.
There are issues with it for carrying disease, all of these different types of things
that we think we that don't want to have a lot of crop residue.
In corn cropping system they actually add a lot of nitrogen
to help decompose that residue at a faster rate.
But why would you want to do that?
Because the residue is protection for the soil, it is providing some nutrients
to the growing plant as some of that residue is decomposed.
It's providing more organic matter and much more food to the organisms that are below ground
that allow for those organisms to grow
and provide all those benefits we talked about before.
So maintaining residue can be one way to couple with tillage that's going to help
to improve the amount of carbonate we have in our system.
Plant diversity is also going to help with the amount of carbonate we have in our system.
And you'd think if you added a lot of cereals, which have a high carbon
to nitrogen ratio meaning for every atom of nitrogen there are 80 to 100 atoms of carbon.
And you would think that that would be good
because the more carbon you have the more organic matter you have, right?
Well, that's not really the case because again when you have that high carbon
to nitrogen ratio, the things that are decomposing that are very fast growing.
They let most of that carbon go back into the atmosphere as CO2 and the nitrogen is consumed
in that decomposition of that carbon.
So you don't end up building a whole lot in that system, but if you add things
like legumes they're going to increase the amount of nitrogen that you have in the soil
and they're going to improve that system so we can get better,
we can get closer to what the average is for soil organic matter itself,
closer to that 10 to 1 or 12 to 1 type of organic matter.
But we're better able to build up that instead of consuming all
of the nutrients and trying to decompose that.
The cover crops are a thing that we're discussing more and more often
as possible mechanisms to improve the system.
And one of the things that the cover crops is doing is it's continuing the amount
of living plants that are growing in the environment and when you continue the amount
of living plants that are growing
in the environment you're getting more carbon exuded absolutes.
You're building up that organic matter in your system.
You're providing more for the mycorrhizal fungi to the mutualistic fungi to be able to grow
because they're directly connected to the plant and from the mutualistic fungi;
they're giving off carbon to bacteria.
They're providing a food source for some of the larger organisms
in the soil, the nematodes and protozoa.
So it's a very good way of being able to get more carbon cycling through
and feeding these different organisms.
And that's going to help overall in building up the amount of carbon that you have.
I want to kind of point out these pictures.
The top one was actually from my dad's farm in southwestern Minnesota.
He does sustainable tillage.
He's not into no till.
And, you know, corn -- soy beans -- he's now converted mostly to corn in his system.
Corn and wheat actually, he's kind of changed up in the last two years.
But what he's done is last fall he came up here to North Dakota and he heard a number
of producers talking about the benefits of cover crops.
So he put in a cover crop into his system.
And then this spring, he burned off the cover crop that regrew even in Minnesota again
where it gets fairly cold over the winter.
He did have cover crop that he planted last fall and that regrew.
He planted it about August 20th and that regrew in the spring, and he had clover and radishes
and turnips in his system, in his cover crop mix.
And so he had a lot of clover this spring and a little bit of turnips growing, as well.
And then he planted it -- he burned it down and he planted it to corn.
And this is on June 19th.
It's about -- not quite a month, after he planted the corn but the corn is coming
up through the stubble that he had left behind.
It was a very cold spring, so you wouldn't expect it to be very high,
but it still shows you that you can add some of these things to your system.
And it's going to be able to continue what you want to have happen
with your cash crops in your system.
There are mechanisms to do it.
There are plant choices that you can make.
There's timing choices that you can make.
There's, you know, cash crop choices.
There's also cover crop choices that you can make that are going to help make this work.
The bottom picture is actually a very interesting producer from Emporia,
Kansas and this is his corn crop, which was planted in June
after he harvested a winter wheat crop.
And then with the corn crop, he put in a cool-season cover crop mixture so it would grow
as an understory crop with that corn crop.
And some of those plants are going to survive in the shade under that corn crop and be able
to grow into the fall after he harvests the corn.
So he's maintaining that living cover as long as he can.
And that's, again, one of the biggest keys about improving the system.
Again, you have lots of different cover crop choices and the plants that you choose,
warm season and cool season, legumes, and grasses, and oil seeds.
Just a tremendous amount of choices that you can make in order to tailor that cover crop
for what it is that you need to tailor it for.
This is a picture you probably have seen before.
This is up here in North Dakota in 2006.
We had a total, where this field was at, a total of 7 inches of soil moisture
and where they planted one cover -- one species of cover crop, the crop died.
It was very dry obviously and it was a pretty hot year.
Where they had the cocktail mix it included both turnips and oil-seed radish.
They had a mixture of that with a number of different crops and that crop thrived.
These pictures were all taken on the same day.
[ Silence ]
>> Now, one of the reasons that that can work is that you can get these things where, again,
the effects are multiplying instead of just adding together.
So if you add no till and crop residue, and then you --
you can also add a cover crop so you've got living plants that are growing,
you're definitely going to have a lot less weed pressure because the seeds are not going
to be able to germinate very well because they're not going to get a lot of sunlight.
There's poor seed-to-soil contact and the seeds with the no-till system are left unburied
as opposed to when you till you basically are burying weed seeds.
If you are able to get this system where you're getting an increase in weed control
without having to use any type of pesticides to do that, this is where I'm talking
about fertilizer use, especially nitrogen, which are the blue diamonds.
There's been a huge increase in the amount of nitrogen that --
that we're using in the United States in the last about 50 years.
There's not been a whole lot of change in the amount of phosphorus and not much change
in the amount of pot ash, but focusing really on the nitrogen
in the system you can see this was done in Illinois at the Morrow Plot.
And they were measuring potentially mineralizable nitrogen so the amount of nitrogen
that can become plant available and what they found is
over time they had a continuous corn treatment.
They had corn and oats.
The oats were replaced with soy beans in '67 and they had a corn-oat-hay type of system.
And they applied nitrogen synthetically as was applicable to the particular crop.
And you know, most of that had been the same since 1967.
Some of it since 1955, but what they found is that between 1955 and 2005,
they would have a drop obviously, in the amount of potentially mineralizable nitrogen;
the amount of nitrogen that you could get
that would feed your plant even though the fertilizer rate was the same.
There was this drop in the amount of nitrogen that was available.
Something's happening in our systems that, again,
is making that nitrogen use sufficiency decline.
And this was done up in Canada and what they found is that the longer they had no-till
in the system the more their production didn't change even if they added more nitrogen.
So if you were in a conventional system or transitioning out of a conventional system,
you needed a lot more nitrogen to try and get very similar yields, instead of being able
to maintain the yield with very low amounts of nitrogen and utilizing
that nitrogen that's in the soil system.
We're seeing that this graph is, again, showing on the left-hand side the cereal yields
over time and that seems to be following fairly closely the amount
of nitrogen that we've applied.
It's the same shape of graph, but when you actually look at nitrogen use efficiency,
so what you are really getting back over time in yield compared to the amount of nitrogen
that you're adding, you're actually seeing a declining curve.
So that's looking at, you know, it's not looking at grain yield increasing
because of changes we've made in management or nitrogen use increasing
because we're increasing the amount of nitrogen, but how those --
when you put those graphs together how they actually look together.
And even though you'd think that they, you know,
look fairly the same it would be an inclining curve, it's actually a declining curve.
We're seeing that when there's more fertility added to the system,
there's not necessarily more yield.
And a lot of that has to do with the timing and the availability and when you work
with the organisms in the soil, they're actually going to change the amount
of nitrogen that's available and when it's available.
You'll get these things where you get interplant transfer.
You'll have -- you have basically a corn plant and legume plant growing side by side.
And in the rooting environment you have fungal hyphae that's connecting those two plants
together and you have rhizobium bacteria that are fixing nitrogen,
and that rhizobium bacteria is fixed nitrogen, it takes a lot of energy just
like it takes to make synthetic nitrogen.
And that energy comes from the cellular powerhouse,
which is powered by the amount of ATP.
You basically take this molecule called ATP and you break off the phosphorus
and that releases electrons to help fire the energy
for the different processes in the cell to work.
And when you do this, you actually need an influx of phosphorus to convert that ATP --
that ADP -- it goes from ATP, which adenosine triphosphate to ADP,
which is adenosine diphosphate and to put it back to ATP, you need an influx of phosphorus.
When the mycorrhizal fungi are associated in particular with a grass plant,
they have better mechanisms, even better than their natural mechanisms to acquire phosphorus.
They work with bacteria that are actually in the fungal hyphae that colonize the surface
of the fungal hyphae and those bacteria solubilize phosphorus for minerals.
It's a way for them to get more phosphorus.
Having them associated with a grass plant stimulates the amount of activity that occurs
and the amount of phosphorus that's acquired.
So the fungus will take some of the phosphorus that it acquired for the grass
and it will transfer it to the legume so the legume can transfer it to the rhizobium.
The rhizobium can fix more nitrogen and then the fungus will take that nitrogen
and transfer it back to the grass plant.
And we're really seeing this effect happen when we have these cover crop cocktails,
crops that are growing at the same time.
So, again, we're getting improvement in the cycling of nitrogen
when we have cover crops in the system.
We're now going to try and improve that nitrogen efficiency because now that we have improvements
in the amount of nitrogen that can be fixed and the way the nitrogen can be transferred
between the plants, it allows us to use a lot less fertilizer because it's providing --
that nitrogen fixation is providing a continuous nitrogen source to both plants in the system
and then their residue is going to have more nitrogen in it and you've got a legume
that has a higher amount of nitrogen compared to the amount of carbon that it has.
So it's able to actually get more nitrogen and the residue was able to get more nitrogen
in the roots to be able to feed these organisms in the soil, but also to be able
to create nitrogen for the subsequent plants to be able to use.
We have to use less fertilizer to do it and that's what's going
to improve our nitrogen use efficiency.
The cover crops, again, can augment the amount of soil cover that you have and even
when you just have residue on the soil, you're not able to cover as much as the soil surface
as you would by the shading of leaves of different sizes.
So when you have a cover crop that has a mixture of different plants that have a number
of different leaf sizes and leaf heights, you're able to better cover that soil surface.
And you're able to -- this was, again, done in North Dakota on those fields
that the previous picture with the dead radishes and the dead turnips,
and the living cover crop mixture.
You're seeing about a 20-degree temperature difference between having that cover
and having just some residue that made it through the winter and spring on that soil.
And that makes a huge difference in the amount of microbes that you get.
Optimized microbial growth occurs at about 80 to 100 degrees.
It starts slowing when you start going above 100 and as you get from about 115
to about 130, it basically stops.
It kills off all of the microbes.
So the previous slide, at those temperatures,
what you're getting is you're getting optimal microbial growth in a field with cover plants --
cover crop plants and you're getting a slow-down and almost a death of microbial growth
when you've got the soil with just a little bit of residue cover.
If you want more information about cover crop species and their growth cycle,
and those types of things, we have a tool that looks like a periodic table.
You actually click on the different plants you're looking for and it will open a window
that will give some more information about those plants.
So you can choose and tailor your cover crops to what it is that you need to have them for.
You can make sure that the system is provided with everything that it needs to be able
to function; things that are going to be able to grow at the different times that you want them
to grow, things that are able to use more water
or use less water depending on your moisture conditions.
All of those things you can pick out and you can tailor this crop to be able to function with.
I'm going to try and talk very quickly.
I know we're kind of going over time and I apologize for that.
I want to talk quickly about soil aggregates, these pellets that are in the soil.
In the lower right hand picture, I want to point this out because a lot
of people are, you know, "My soil is too sandy.
I can't grow stuff here.
You know, I can hardly grow my cash crop how do can you expect me to grow my cover crop?
I can't get all of these benefits because I can't get organic matter in my soil,"
all of these different things that they're talking about.
This lower right hand picture is actually from a pot culture system that has been growing
for three months and when I'm doing experiments in the greenhouse a lot
of times they use a one-to-one sand soil mix.
So I added a lot of sand and you can see that it's fairly sandy in there.
I added a lot of sand and after three months, I'm still getting this level of aggregation.
The picture on the lower left is actually a millet root
that was planted as part of a cover crop mixture.
This sample was taken from a plant that was planted on July 7th.
I collected these roots on August 31st and the previous crop,
before the cover crop was put in, was a forage pea.
This is on the particular cover crop root and you get all of those aggregates that are formed
in that rhizosphere environment right around the root.
You can't even really see the root.
It's hidden by all of these aggregates.
So, again, in a very short period of time in very sandy soil --
the picture on the left was actually -- it's a sandy loam soil that it was growing on.
So, you know, in these soil environments you can still get a high level of soil aggregation.
The soil aggregates again, have been reformed by the amount of the fungal hyphae.
The fungal hyphae you can't see in this picture.
It's clear hyphae, but you can see the effect of it because it's holding those clumps together
and those clumps right now, are primarily just I separated them from the soil by wet sieving.
So they're primarily just plant debris and fungal hyphae, and a little bit of clay minerals
and possibly a little bit of silt minerals.
But there's not very much sand in here and you'll see how the fungal hyphae --
I did wet sieving, so I broke this up and then I washed it off of the sieve into a glass plate
and I let it sit for a couple of hours and it started forming these nets that started
to bind all of this material together.
So this is sort of a pre-aggregate formation.
When you get aggregation you reduce the amount of compaction in your system.
You're going to get -- those pellets come in different shapes and sizes,
and so they don't fit together exactly and so they create space in between them and that space
in between them is the porosity, the amount of porosity that you have in soil.
When you have greater porosity you're going to have greater levels of microbial activity
and microbial growth because that porosity helps moisture get into the soil.
It also helps air to get in the soil and it helps CO2 to escape the soil.
Most of the organisms that are in the soil conduct respirations the same way we do.
They take in oxygen and they give off CO2.
But they are, again, trapped in the environment and the amount of compaction that you have
when you reduce the level of porosity because you're
in a compacted environment the less those gasses can exchange
so the less microbial growth you can get in that environment.
Water management is an important part of having these aggregates because you're creating
that porosity where you can get water to go into the soil much more quickly
and you can keep water stored in the soil for a longer period of time because it is stored
in that pore space, in that open space.
And I like to -- this is a study that was done in Missouri and I like to sort of point
out that kind of it was summary on several studies that were done called the 'drought myth'
and basically, what it said was that you could have unfertilized corn
that would require 26,000 gallons of water per bushel, but if you fertilized
that field you only need 56 gallons of water per bushel.
And what is it that is happening here is
that you have greater fertility in that soil environment.
The plant roots, in order to get fertilizer from the soil, give off water to create mass flow
for the different fertilizer -- for the different nutrients;
for nitrogen to flow towards the plant roots, for phosphorus to flow towards the plant roots.
They give off water to do that.
But if you can circumvent the amount of water that they give off, either by adding a lot
of synthetic fertilizer really close to where you plant the seed, so if the plant is able
to acquire a lot of that fertilizer and utilize it
with very little water give off for the fertilizer to move.
Or, if you can circumvent it via the mycorrhizal fungi, which I said are very efficient at going
out from the plant roots so the plant roots don't have to give off any water.
They give a little bit of water to the fungal hyphae,
but for the most part the fungal hyphae acquire that water from the soil.
So the fungal hyphae grows out of the roots and then picks up those nutrients
and carries them back to the plants.
You don't get a lot of this water loss and it's going to require less water in your system.
As you increase the porosity level of your system you get 44% greater --
as you increase the amount of porosity you have in your system,
you can increase the amount of infiltration.
And just if you increase the porosity by about half, you can go from 167% to increase
in water infiltration for the first inch and 650% increase for the second inch.
So it dramatically increases the amount of infiltration you have.
The porosity also can reduce the amount of drying that you have
because basically what it forms is it -- as you have those aggregates that are there,
the water has to move and curve, and bend around where the aggregates are
because those pores aren't straight channels from the surface into the soil.
Because of those moves and those bends in the curves,
the evaporation off of the soil surface is slowed.
It's basically like putting bends in a straw.
If you put bends in a straw, it takes more energy to try and suck out the water that's
at the bottom versus if you don't have bends in the straw it's really easy,
you don't have to suck very hard.
So what you want to do is you want to have bends in the straw that's connecting the above-ground
to the below-ground so that more water is going to stay in that environment.
Water infiltration rate increases.
You've got a conventional system that's on the left hand side, conventionally tilled
and as you can see most of the soil that's at the bottom,
this is down about three inches from a rain fall simulator.
You can see most of the soil at the bottom is not wet.
If you go to an undisturbed system, a no-till type system,
what you're getting is you're getting more water that's making it
through so this is saturated all the way down three inches.
It also has higher organic matter levels than in the conventional system
as you can see by the color differences.
[ Silence ]
>> So when you get aggregates in systems you're going to improve porosity,
which is going to reduce compaction, allow for better root growth.
It's going to allow for better aeration, better water infiltration,
and better water holding capacity.
The aggregates are also going to be a lot less susceptible to erosion
because when you have material that's bound together in a pellet, it's larger in size
and it's going to take more energy, stronger rainfall or stronger windstorm to be able
to move that than it is going to be for all of the fine particles
that would be individually in the soil.
And it's going to improve the nutrient cycling
by providing a protective habitat for the bacteria.
It's going to protect organic matter and that's going to be a good source
for the bacteria as far as food is concerned.
You're going to be able to have this better environment in the system
for better root growth and for better microbial growth.
This basically illustrates some of the management impacts on the amount
of aggregates and the stability of aggregates.
In the top three pictures, you have one that came
from a conventional till, spring wheat fallow system.
The next one is a no-till spring wheat, winter wheat, sunflower system
and the last one is a moderately-grazed pasture.
These aggregates were separated from the soil by passing through a series of screen
so they're all one to two millimeters aggregates.
They're all the same size.
When you add the same amount of water to these dishes, what you'll find is the WSA
or water stable aeration increases as you go from a management system
that has less soil disturbance and more plant growth for a longer period of time.
And you also increase the amount of TG, which is a, excuse me, a total glomalin,
which is a polysaccharide type of substance that's produced by mycorrhizal fungi.
It helps to contribute to the stability of the aggregates.
You get -- as you change management you actually impact, on a relatively small scale,
these aggregates and that's going to have a really strong impact on all
of these other activities that you want, reducing compaction erosion and the like.
So what you really want to do is focus on management and not just getting the job done,
not just completing it, but actually looking at the steps
that you utilize in your whole entire system.
And I believe that the new green revolution is actually going to be a brown revolution.
It's going to be looking at the soils and soil environment,
figuring out how to utilize resources the most efficiently, getting those resources
into where they need to get in with the least amount of loss of water
and the least amount of cost to carbon.
And this doesn't really mean they should have to work all
that much harder, you just have to work smarter.
You have to, again, look at your whole entire system.
You have to look for what you need for pest management
and what's the best, most efficient option for that.
Look for increasing the balance in your carbon and nitrogen ratio.
So having high carbon, low nitrogen, and high -- low-carbon, high-nitrogen plants in your system,
you want to make sure that you protect your soil, keeping it covered by living plants
with different leaf sizes and different placements
or by having residue on that surface of the soil.
You want to keep that soil environment protected
from temperature increases as well as rain fall and wind.
So you want to make sure that that environment stays there.
And again, you really want to use your water resources
and your nutrient resources most efficiently.
It doesn't matter where you are, that's what you want to do.
Whether you're in a dry environment or a humid environment, a cold environment
or a warm environment; all you want to do is improve the efficiency
so what are the steps you can take to do that.
And thank you, again, I apologize for taking so much time.
If you want to contact me, that's my contact information at the bottom
and I guess we'll go for some questions.
>> Yeah, [chuckle] I hope everybody appreciates the presentation you just heard.
If you've ever had to make a presentation sitting in a room by yourself
and to cover a topic so thoroughly and discuss it for 90 minutes; I'm very impressed.
Fortunately, we've been able to capture this and it's been recorded and I'll show you in a second
where you can go back because I'm sure a lot of us are going to want to do that.
Operator, right now we -- we have an opportunity to -- let's take a few minutes;
I know we're running over, but hey, we've got nothing else to do.
Take a few questions and see what's -- if anybody's out there.
I'm not sure.
You know, there might be -- I had a couple here -- there's a lot of controversy out,
I know in the Great Lakes area, Chris, about earthworm holes and the movement
of specially dissolved phosphorus.
You got a comment on that?
Is that -- have you done any research or read anything on that?
You know, they're actually blaming some of the contamination of the Great Lakes on no-till
and water movement down into field tile.
Have you got any experience or comment something like that.
>> I guess I would say I don't have much direct experience with some of that.
As far as the earthworm tunnels go, I would say that they're --
although they're creating a tunnel to be able to get water into the soil pretty quickly
and that can move some phosphorus and it can move some nitrogen into that soil
and that can get into your tile drainage system and possibly even get
into the groundwater system a little bit more quickly.
But what they are doing as far as increasing the amount of carbon that's going to be available
to the different microbial species that are going to be able to utilize that nitrogen
and phosphorus in a way that's going to keep it out of the river systems
and lake systems is going to, in the long run, be more beneficial.
There may be, you know, just like anything, there may be a few places
in which it's not working quite as well as it should or, you know,
the system just hasn't gotten to that point.
The other thing, by having the microbes growing at that --
along those tunnels, and the polysaccharides that are left behind by the earthworms
that can really help contribute to aggregate formation.
And when you contribute to aggregate formation that's another way of locking up some
of those nutrients because you're going to -- they're going to be inside the aggregates
and the aggregates, again, are going to create those tunnels and those channels that are going
to have curves and bends in them, which will slow the rate of flow
of the water as well as those nutrients.
>> Okay, thank you.
We had a question come in.
And somebody wants to know what the role of higher animals,
grazers in the overall nutrient cycling and in this whole discussion
about improving soil quality and the soil bio.
How significant is that to work into a system?
>> It's something that we're learning more and more about.
Again, there's been a lot of decoupling of grazing systems from agronomic systems
and as we see those systems come back together, we're actually seeing better nutrient cycling.
And there's something that goes on with grazing that I don't fully understand
and I don't think anybody fully understands because we try and look at the microbes
that are left behind in the manure, the microbes that are growing
in the near -- where the urine is excreted.
And we're not able to figure out exactly what's happening, but there's something
that is occurring with, possibly with what types of organisms they are or what some
of the activities they're having in that particular environment, that can't be replicated
by haying it off or you know, mowing down that residue.
There's something with having that higher animal on the fields and on the system that's going
to allow for better management of those nutrients.
And especially if you're putting the livestock out to graze the fields
or graze pasture systems rather than having them in feed lots
because you're getting a greater distribution of those nutrients that come from the manure
and from the urine as well as the microbial populations that come
out of the ruminants with the manure.
>> Okay, I've got two questions and then we'll close this thing off.
You introduced a new term; sustainable tillage.
What is that?
>> Ah, [chuckle], sorry.
Sustainable tillage is going away from the moldboard Plow.
So it's sort of a reduction in tillage.
I heard about it as a kid from what my dad was doing when they went to these different things
with doing terraces and going away from the number of passes that they were doing.
So they were doing fewer passes in the fall and you know,
trying to just create the seedbed in the spring.
It's still doing tillage, but it's sort of modifying it
from the more conventional intensive multitask deep tilling type of equipment.
>> Okay. Okay.
We've probably coined the phrase conservation tillage or...
>> Conservation tillage, yeah.
>> Okay. I had a question come in about the use of BT crops and what is the effect
that these are having on biological activities and is it going to be problem
with excessive residue because we've heard that there's a slowing
down of the breakdown process using BT crops?
>> Yeah, I have also seen quite a bit of data that's looking at the slowing
down of the residue decomposition of BT crops.
I've looked at several different research papers.
I haven't conducted research in that area, but I have some colleagues that have
and there are some that have looked at the microbial community
and have said there's no difference between BT corn and non-BT corn
and there are some that have said that there is.
A lot of that, I think, does have to do with where you were sampling.
Like I said, sometimes you'll hit the spot that is the greatest spot on earth
and sometimes you'll hit the poorest spot on earth
in the same field under your sampling regime.
So I think that we're going to find that a lot of it has to do with that.
We're finding out more and more about what's happening in a rhizosphere environment
with introducing genetics and introducing some of the pesticides that we use
and the impact that that's having.
That's just -- I think I'm going to say, more of a stay-tuned than we really have any answers,
but we're definitely working there.
>> Okay. Last question, the soil-food web analysis that's available out there from --
well, I guess it's from the soil-food web; you've got a comment on that?
Is that something that's worth pursuing or...
>> I do -- the soil-food web analysis and I've worked with several people
who have sent some samples for soil-food web analysis, there's been a few places
in which I think some of their methodology have some problems with it as far as being able
to get some good numbers for, especially, I did stem analysis on mycorrhizal colonization
and ended up getting some very different numbers from the soil-food web lab.
So, you know, I think there's some information that we can take from there and, you know,
look at things like the amount of protozoa and nematodes, and bacteria to maybe get some ideas
about nitrogen, potential nitrogen availability.
I think there are some other labs that are coming online that are trying to do analysis
on the soil-food web and they may have some better ways of looking at it.
Some of it may be a little bit harder to interpret.
We do things like fatty acid analysis and DNA analysis to try and identify groups of organisms
and sometimes that can be difficult to do and expensive to do as well
as a little bit difficult to interpret.
And the more we're building up a database of information
for agricultural food the soil-food web is located in Oregon.
It's works -- it's been associated mostly with the horticultural industry,
which is a very different environment because usually they completely sterilize their soil.
So I think that just like with soil testing, there's some misinterpretation that can be made
because we don't know what the baseline should be.
So the more we can get different soils analyzed the more we can get information
on what the baseline should be so what makes things good or bad because we don't really know
that very well for a lot of agronomic systems as far as individual species and amounts needed.
>> Okay, all right.
Thank you, doctor.
For those, a soil-food web analysis is just a measurement, a quantitative measurement
of the various organisms that Dr. Nichols talked about.
Again, we appreciate your participation.
Just before I close out, I just want to make folks aware of two things.
You can listen to a replay of this presentation at this website,
which is the new Science and Technology Training Library.
If you go to that, I'll just click on it real quick; this is what it looks like.
You can access it there at the address that's on the webinar.
Here's the one -- the last one we did.
We will post this presentation there.
If you hit download, you'll just simply go to a PDF file here that gives a description
of what the objectives were, gives a basic description of what the training session was,
and then you can either hit play or download.
I would suggest you hit the download because that gives you the opportunity to pause and back
up or fast forward through the presentation where the software,
if you hit the play, doesn't allow you to do that.
And then the final, make sure you get your presentation or your information into us
about the -- if you have, your CCA credits.
Make sure you get that information either faxed or emailed to Holli Kuykendall.
And then the last thing is, our next MRBI presentation will be on Wednesday
and that should be August the 10th, not July the 27th, that's a cut and paste error there.
So again, Wednesday, August the 10th.
It'll be Mark Scarpitti who's the state agronomist from Ohio,
and he's going to be building on what Dr. Nichols talked about,
how can you take these principles and put them into a conservation plan and use them
as the foundation for resources management, looking at planting to improve soil health,
managing more by disturbing less, diversifying,
growing a living root throughout the year, and keeping the soil covered.
Those are the basic principles he'll be covering and he'll be talking
and just kind of expounding on that.
With that, I appreciate everybody's participation.
Again, Dr. Nichols, you did a great job.
And I am sure, everybody, from the responses I'm seeing and the Q and A,
and the applause I'm getting over the computer here, everybody's in agreement.
So again, we thank you and I guess that will just call it a day.
Thank you.
>> Thank you.
>>
[ Silence ]