字幕表 動画を再生する
(Dr. Jaradat) We live in a world of salt, but we do not recognize it.
(Dr. Cihacek) Once it's salinated, you got a problem.
(Dr. Hopkins) One of the points that many, many farmers have said is
that they're seeing salts in places
that they'd never witnessed problems before.
(Harold Steppuhn) If I'm a producer and on my ground,
I've got a problem with it-- it's not overblown--
that's my livelihood off that land.
Funding for "Salt of the Earth"
is made possible by an EPA Section 319 grant
administered by the North Dakota Department of Health.
the Eastern North Dakota
Resource Conservation and Development Councils,
with support provided by the...
...helping people help the land,
and by the members of Prairie Public.
It's a waste of fertilizer, seed,
and your time and effort on it.
It went from, I would say 5% to 10% of the farm acres
being affected by salinity to up to 40% to 50%.
Salinity isn't a new problem, it's a worldwide problem
(Matt Olien, narrator) If you've driven by farm fields in the Upper Great Plains,
you've no doubt noticed patches of white,
chalky soil, usually near roads and ditches,
that just doesn't seem to belong,
and doesn't seem to go away.
Farmers wish it would.
It's soil salinity, too much salt in the soil,
and it can prove nearly impossible
to grow a productive crop in those areas.
Overall reduced soil health, so compaction issues,
reduced biological activity.
You don't have as good of soil to till.
It's harder to work the soil.
A lot of that depends on your strategies
you're using for management-- if you're using
conventional tillage or no till or strip till.
But it really depends on the producer
and what they're willing to try.
In my area I would say
over 95% of my fields have salinity,
and 80% of them have visible white spots
that are well in excess of this.
All of my producers are very concerned about it
and are actively looking for answers and trying new things
and trying to seed some cover crops,
trying some crop rotations, trying some limited drainage
when they can get the permission.
So the producer is going to try to pick the crop
that gives him the best option and economic return.
(narrator) Excess Salinity is caused generally
by too wet of conditions resulting in a high water table.
Most agree the problem in the Upper Great Plains
got worse around 1993
when the dry cycle converted to a wet cycle and has never left.
But the problem has been around for centuries.
(Dr. Jaradat) The land in Mesopotamia is very flat,
and irrigating that land created problems
in addition to the high temperature
and high evaporation from the irrigated water.
Salts became concentrated, and the irrigation water
coming from the twin rivers, the Tigris and Euphrates,
enriched that salt in the Mesopotamia plain,
and in less than 1500 years,
the problems started showing up
to the point that most fertile parts
of lower Mesopotamia turned into white crusts.
People went hungry, and cities
and the empires themselves crumbled
because of the loss of their wealth.
(Dr. Cihacek) This is a geologic process
so it's been going on for a long period of time.
We've got relatively young glacial soil.
A lot of our soils were pushed in here by the glaciers,
spread out on the landscape.
So as these salts weather-- they're young materials;
there's a lot of things to weather in there.
They dissolve and go into the water.
Then wherever the water goes, they carry these salt minerals.
(Dr. Abdullah) Although it is a problem here,
but it's no comparison
to the salinity problem in other parts of the world.
Just to give you an example-- California,
the Joaquin Valley and the Salton Sea.
The problems there are much bigger.
The world is losing approximately
a million hectares a year to salinity,
and there are 200 million hectares of saline land
which is not producing up to its productive capacity.
There are issues in the Nile Delta
especially after the construction of the Aswan Dam.
After the construction of the dam,
this kind of natural remedy, so to speak,
of soil fertility and handling salinity stopped abruptly.
Based on that, in fact, major health problems were created.
(narrator) In our region, the topography of the land
has lent itself to salinity problems,
forcing many farmers to move this land
to the Conservation Reserve Program.
When the glaciers came through here,
they ground up to pure shale,
and most of the salinity that is in our soil
originated from the pure shale formation
in Eastern North Dakota at least.
We were just looking in our training yesterday
at a soil survey that was completed
in Stutsman County back in the '80's
before the wet cycle really started.
There was only, I think, about 10 acres
of a whole quarter section that was mapped saline.
I believe that there's no question
but that some of the salinity that we're seeing
and the degree and the nature of the salinity,
it's a function of what we're doing with water.
It's linked to the Red River Valley floods.
It's linked to overland flow.
So consequently what that means is,
is that there's simply more water on the landscape.
More water either runs off the landscape.
More water resides within the landscape, and there's
less water that is moved back up through evapotranspiration.
It's roughly 10.8
deciSiemens per meter.
And in this type of sampling,
it'll show less salts 'cause we have
a higher concentration of water with this soil, but that would
easily equate to 25 deciSiemens on the other methods,
and that is restrictive to almost all plant growth.
(narrator) Salinity can be invisible or visible.
Either way, it is affecting the bottom line and livelihood
of producers all over the Upper Great Plains.
Joleen Hadrich with North Dakota State University
has researched the economic impact of salinity.
What we know is that their yield is going to decrease,
and that, of course, is going to relate
into lower revenues and a lower profit level.
Slightly saline would result in about a 15% yield loss.
The moderate would be 50% yield loss.
When I applied the average crop prices
that we're receiving right now in those yield decreases,
it resulted in $150 million decrease in revenue.
(Bill Schuh) I think it's first and foremost a crop problem
and secondly an economic problem.
The loss of crop yields from salinization of the soil
is a very, very major economic loss for our state.
(Joe Breker) I did a recent poll
with our group, our corn growers group, and it was
fairly common to have producers from all over the state
that are in the corn growers that had from 10% to 15%
of their farms severely impacted by salinity.
In terms of an overall problem, we could say
that the agricultural land in Canada,
about 1/3 includes salt-affected soils.
If I'm a producer, I will try to minimize that--
any kind of problems that relate to salinity--
primarily because my assessed lands,
the assessments, will decrease
if my lands are identified as salinized.
When we get to an EC of about 8 which is moderately saline,
we have at least 50% reduction in yields on wheat.
You can have 75% yield loss on corn,
and soybeans, you might as well forget it
because we're down to maybe 10% or not even worth harvesting.
Basically it's an osmotic problem.
If you get too much salt on the outside,
you have too much osmotic suction on the outside,
it competes with the electrolyte in the plant,
and the plant reaches a point
where it can't imbibe water properly,
and you start getting yield reductions.
(narrator) Another fear is what has happened
in other parts of the world.--
health issues, food supply issues and water quality issues.
We constantly review the best available science from EPA
and their contractors that they work with--universities
that develop the best toxicological information
that's available to date, and we incorporate those.
If it's something immediate, we do it right away
in our water quality standard.
(Bill Schuh) I don't think that on the basis
of current EPA and CDC documents we can conclude
that sulphate is particularly damaging to water quality.
As far as drinking water quality is concerned,
people drink water that have a lot of salts in them.
There's a very wide range of qualities in the waters
that people drink and are capable of drinking.
Right here in this area of the field--this is one of
the more obvious places that you'll see salt.
The obvious effects of the salt is this white crusting.
I see too many guys trying to manage their salinity.
They put some into CRP, but they don't go far enough,
and then that salinity just continues to move out,
and then they're mad because they don't have an impact,
and it's just making it worse and worse.
(narrator) And as you'll see next, the solutions farmers come up with
can mean the difference
between lost revenue and successful yields.
Good management practices for salinity would include
definitely CRP, understanding that,
the variable rate and site specific technologies
is the biggest one that I'm involved with.
(David Burkland) Actually in Grand Forks County here,
the level of salinity is
one of the higher levels in the Red River Valley
so we've tried a lot of different things.
We have put some land into CRP,
but we've done other things too
to try to overcome the saline conditions--just crop choice
is a big factor, picking the right crops.
Picking crops that are tolerant to saline conditions
is real important.
(Shawn Kasprick) On the precision ag side of things,
we got different site-specific products
and services that we can provide that will give the growers
a handle on where their salinity is,
what impact it has on their crop, and how far out
that impact really is effecting their crop.
That all will wrap up eventually
into a variable rate application for fertility
and eventually the grower's bottom line.
(Joe Michels) It takes a little while to get established.
It did the job for me.
We have had salinity issues.
There's one hayfield we got from a fella that got sick.
He told the landlord that he
wanted to rent it to my dad
back in the early 70's.
We took it over; the ground was white.
It would grow foxtail, kochia, and not too good at that.
Then the garrison seemed to help.
It took a long time to establish, but it is very thick.
We got a good root structure
where Dad could drive across there with a swather
in the water and not get stuck.
(Dr. Cihacek) Cover crops, especially deep-rooted cover crops,
can have an effect on lowering the water table in an area.
My favorite crop to lower water tables is alfalfa
which is a perennial, permanent cover type crop.
Alfalfa is very, very deep-rooted.
(Hal Weiser) Out in Montana, they've really had a lot of success
in addressing saline seeps
and addressing how to correct those situations.
One thing that's happened- there's been a shift
in the western part of the state to no till
so they've gotten a lot more efficient at water.
A couple of years ago in 2008,
we did a special initiative through the Equip Program
which allowed us to provide cost share
to producers that were having issues with salinity,
and that was specifically on saline seeps.
What they wanna see is which direction the groundwater
is flowing when they start testing this,
and then they wanna see the levels of the water.
And as the water goes down, that means the salts are going down.
The soil on the surface is more productive
as the salts go lower into the soil profile.
I can't honestly say what that piece of ground looked like before,
but I was out on it last year on our crop tour,
and like he said, you don't have the boggy areas out there.
We drove across that with vehicles with a school bus.
There's good ground cover, and it's actually very productive.
(Joe Michels) We are able to seed everything.
If you get something growing out there,
use up the water, try to push the salts down.
[motor purrs]
(Paul Overby) So this is the obvious saline area
where we've got the while soil,
and nothing is growing except kochia.
So we get back to almost the same spot every year
so we've not skewing our results
by testing one spot one year and then two years later
coming back and doing something that's better.
We're probing the same area.
We've done that consistently now for four years.
(Paul Overby) The reality is, the water tables all over
the Devils Lake Basin are full to the point of discharging.
We've had years in this area
where I got stuck on the side of a hill.
What we started doing was actually developing
zone management for our fields.
That idea intrigued me, of being able to apply
the right amount of nutrient in the right parts of your field
to match the crop yield potential.
We actually use our experience then to tell the story
as we go out and do seminars and meet with farmers.
And a lot of farmers are a little surprised just like I was
that the saline issue was much bigger than what they see.
Almost every farmer says well, I turn my fertilizer off
when I go through those white areas.
I don't fertilize those areas; I know not to do that.
But they don't realize how far away the saline issue really is.
And so when we create maps for those farmers
and then delineate that out, that makes sense to them.
Then we started the business
of making those maps for other people,
training people how to use them,
doing seminars for people and pointing this out.
This is part of the management.
I think the first solution is (1) recognizing the problem,
and then (2) keeping after it.
It isn't ever gonna go away.
Water moves up and down in the fields.
We've been doing some work on this probably going into
our 3rd year now, and certainly when salinity is really high,
then we get very low, almost no yield in potatoes.
Especially since 2005, we had a lot of rain in our area here,
I know just across the line they had some similar difficulties,
definitely brought more saline to the surface, and since then
we've had a little bit more
quality problem with our potatoes.
There's really nothing that physically,
chemically I should say, removes salts.
You're not gonna change the composition of that.
You have to either physically either drain the salts away
or put in a crop that can tolerate
the elevated levels of salt in the soil.
Late '90's, we chose to put
a lot of our most severely saline land into CRP.
That was a good option.
I mean, that was an excellent option for us.
So we put a lot of that land into CRP,
and they used tall wheat grass, for example.
We've always tried to keep crop rotations.
Winter cereals are good because they will generally grow
on saline ground better than row crop like corn or soybeans.
But you have to grow what makes money,
and not that winter wheat isn't good,
but you can't raise winter wheat every year or you can't raise
sunflowers every year so you have to raise a rotation,
and some of those rotations aren't always very salt tolerant.
(Rick Burgum) Well, the best way to reduce your salinity problem
is to drain the surface water.
Oftentimes you can't do that.
The passive ways to do it are to grow something,
but you have this contradiction 'cause nothing grows.
The best thing to do is to grow your way out of it,
and we gotta find crops that will grow,
and then we've got to be able to practically grow them.
What we've doing on this plot is trying to show differences
in management, things that we can do to help assist
salt mobility and try to get crop production and growth.
With this research here, we're trying to show that tillage is
not an effective management tool for saline areas and salt areas,
specifically when they have a lot of sodium
but also when they have a lot of calcium.
In these plots, we did some tillage, we did some no till,
we also did some no till with straw cover to reduce evaporation.
I really have 3 basic treatments.
I have high evaporation,
what we would call a normal evaporation here
with our no till, and then also reduced evaporation.
And what the evaporation does is bring the salts to the surface.
So we're actually increasing the salts in the concentration
at the surface with the tillage and the no till.
The only treatments that are helping us to reduce it
a little bit is with the straw.
I think the drainage is a big thing
to get rid of the excess water first,
and that'll help probably pull away from--
it'll start to shrink some of these ponds,
and that way the salts will start disappearing on their own.
We've been in kind of a wet cycle
so that's probably part of the problem too.
From here to there the salinity was twice as much on this plot
as it was there, so within ten feet we had double the salinity.
Even though there's not a lot of topography change,
there's no soil type change, it's a water mobility thing.
We have downward movement of water right here.
With the resource concerns
that we coming into our office,
we just really felt we needed to have some training
for our employees on how to handle salinity
and how to work with producers on salinity.
You know, the work that we're doing right now in North Dakota
on working with producers as NRCS
we are looking at trying to get into the rotation
more salt tolerant vegetation or trying to get cover crops
that are more salt tolerant of salinity--
to try to treat the saline areas,
but we're also looking at total landscape water use.
(narrator) While growing salt tolerant crops like alfalfa
and barley or putting land into CRP are long standing ways
of dealing with and fighting salinity, a third solution is
more expensive and potentially more controversial.
It's the installation of subsurface drainage pipes
that are perforated so they're put at a depth
to reduce the drought water levels below a level
that'll allow the water to rise to the surface.
And what it does is, it drains excess water
that is not needed for crop production.
It doesn't affect the crop, the water that the crop needs,
but it drains excess water, and it allows
better aeration of soil which is also important for crop growth.
And with that, the salts move with the water.
So wherever the water goes is where the salts are going to go.
Other than that, there are other things
with sodium levels in the soil.
If you have high sodium levels,
the potential to leech out the calcium salts
will change the physical properties of the soil,
and it can actually accentuate
or make the soils less fit for crop production.
There is some danger with understanding essence
of tile drainage, knowing your soils is very, very important
before you install tile drainage,
and having an understanding of the history
and the potential for sodium-affected soils
after you start to drain that water out.
Tile drainage works. The advantage of tile drainage
is that it allows the farmer to regulate
when it gets in the field and when it gets out of the field.
If there's a large rain, the land manager can
pretty much guarantee that within 3 to 5 days, you're
going to be able to get into that field with tile drainage.
Without tile drainage it might be 7 to 12 days.
(narrator) Roxanne Johnson with North Dakota State University Extension
is in the midst of a 5-year study on salinity,
including the impact of tile drainage.
Where you put that outlet is really, really important.
Don't put it upstream of someone's home
so it's running by their house so they have
excess water sitting in from of their homes.
[chuckles] I'm a farm girl, so I'm afraid
that if we don't have tile drainage that there won't be
farming as we know it in eastern North Dakota
because of the high saline levels in these fields.
You talk to these producers,
and it's the best thing since white bread, apple pie!
(narrator) But other research from Joleen Hadrich
looked into the economics of tiling
which can cost farmers nearly $600 per acre to install.
I did my analysis assuming $4.75 per bushel of corn,
and now it's trading
at $7.00 a bushel on the futures market.
Drainage tile would make a lot more sense now,
but at $4.00 corn and a yield of 120 bushels per acre,
the farmer would be losing between $2.00 to $20.00 an acre
if they put in drainage tile.
It is expensive, but it took land
that was virtually worthless
for annual crop production
and made it good to excellent crop production land.
Tile drainage, what we are doing here
in the Red River Basin is
installing drain tile to remove excess subsurface water.
There's really one reason why farmers are
installing drain tiles on their fields,
and it's for increasing crop production.
We've tiled fields that farmers tell me
are their saltiest fields, and in a few years,
probably 3 to 5 years,
they are yielding as good as their best fields.
You look back here,
and anytime you see a pump pumping water,
you know there's a perception
that you're making new water,
and that is untrue.
What we're doing is, we're
lowering the water table,
and we're creating a reservoir in our field.
We've done a variety of things.
We are drain tiling, trying to get rid of some of the salts
that naturally through the rain will percolate through the soil
and go out through the drain tile.
We've got an interesting project with the University of Manitoba.
There's a couple of Ph.D. students doing their thesis
on water movement and saline soils,
and we have got a replicated trial here
in the back of this farm of about 15 acres.
They will be trying to determine how the saline areas
are mitigated with drainage and irrigation.
(Dr. Cihacek) Once you take that water and move it somewhere--
you gotta move it somewhere-- put it into a drainage ditch.
The problem with our flat landscape is,
it's hard to move it any long distance.
The water that comes out of the drains contain salts.
Now, my concern is with the drainage that you can have
a transfer of a problem from one field to another field
or another area because that water is going to contain salts.
If the water cannot flow off freely, it ponds up.
Then we've got the potential of salinizing other land.
Some of the preliminary numbers that I've reviewed
suggest that the total dissolved solids
in some of the tile drains are very, very high.
I've seen them 10,000, 15,000 milligrams per liter--
some very high sulphate numbers also.
Now, one or two individually
probably doesn't have a great effect.
What's unknown is the cumulative effect
of widespread tile drainage on the tributaries
flowing into the Red River and the Red River itself.
We do know that nitrate, for instance, seems to be
very, very high in tile drainage waters.
Salinity is a global problem,
but the solutions to that should be and must be local.
(narrator) The causes of salinity are many,
as are the potential solutions.
The key for farmers and soil experts is
to curtail the problem before it reaches levels that have caused
economic collapse in other countries, in other times.
National, state and local solutions
will hopefully converge to win the battle.
Some of the crops as North Dakota shifting into
more of the corn belt types of production
with corn and soybeans.
We're going to see more problems emerge
with saline soils if we aren't careful.
(Dr. Hopkins) We have soils that are very, very productive,
but you can drive any road in North Dakota
and see examples of egregious erosion.
As government agencies, we need
to work with the growers--
corn growers, soybean growers and really try to address
this resource concern in North Dakota.
The universal advice which I would like to repeat is
instead of adapting the soil to the plant,
adapt the plant to the soil
as a biological long-term,
less expensive, and permanent solution.
Funding for "Salt of the Earth"
is made possible by an EPA Section 319 grant
administered by the North Dakota Department of Health.
the Eastern North Dakota
Resource Conservation and Development Councils,
with support provided by the...
...helping people help the land,
and by the members of Prairie Public.