Woman: The following presentation
is part of the Agronomy and Horticulture Seminar Series
at the University of Nebraska-Lincoln.
-: Good afternoon all, and it is my great pleasure
to introduce Dr. Juan Pablo Monzon.
Pablo is currently a research assistant professor at UNL.
He has a PhD degree
from the University of Mar del Plata in Argentina.
Before that he got his BS on Agronomic Engineering
from the University of Mar del Plata as well.
He is now a research assistant professor at UNL as I said,
but also he holds two positions in Argentina.
One as an associate research scientist
at the National Scientific and Technical Research
Council of Argentina.
Another one as an associate professor
at the university of Mar del Plata.
And in these positions,
he has a dual research and teaching role,
and Pablo also works as a private crop consultant.
So in a way he has a triple appointment,
including teaching, extension, and research appointments.
And the areas of expertise of Juan Pablo
are on sustainable cropping systems,
crop ecophysiology, crop modelling, and intercropping,
and he is a very prolific scientist.
He have been publishing more than 20 papers
in peer review, international journals,
including a recent one in nature of sustainability.
Plus another two book chapters, and more recently,
and as a part of his work here at university of Nebraska,
Pablo has been focusing on projects
related with oil palm intensification in Indonesia,
as well as an another project
on soil nutrient mining,
in South American cropping systems.
And finally, I want to warn you
that Pablo is also a farmer.
Every year he grows sunflower, soybeans, maize and wheat
in more than 2000 acres back in Argentina.
So be aware of that when you ask a question to Pablo
or when you are proposing him to do things differently,
because he's gonna go back home,
try whatever you're proposing
and then let you know if you were right or wrong.
So keep that in mind when asking things to Pablo.
Having said that,
again, Pablo is a pleasure to have you today with us,
and I will let you now to show the presentation
and it start your directory to them.
Thank you very much.
-: Thank you for this presentation
and welcome everybody and just thank you all,
just to let me share part of my work
that I've been doing here
during these last two years here at UNL.
Okay so, I will be talking today
about soil mining in cropping systems in Argentina.
So, this is part of the work that we have been doing
here in Nebraska,
in collaboration with ReTAA.
ReTAA is the research division
of the cereal board of trade of bona fides
and also with ifa,
that is the international fertilizer association.
So let me first start with some of global trends.
So we are assuming that there will be an increase
in the amount for food
by around 50% by year 2050.
This will be mainly due to an increase in the population,
and also due to changes in the diet.
The annual yield gains are not sufficient,
just to meet the future demand
on the currently cultivated land.
And as a result, there is a massive expansion
of the cultivating area during the last decade,
of around 13 million hectares per year.
And in many cases,
this is at the expense of natural ecosystems
like tropical forest, for example, in Brazil
or in places like Indonesia for example.
So, there is also a post-pandemic scenario,
where we have high grain prices,
and also an aspiration of the countries
for just, for rapid economic recovery after the pandemic.
So all these things together,
are putting a lot of pressure
just to increase the area,
and to increase the production of our food.
So we can say that, satisfying that future demand
for food, without massive expansion
of the cultivated area,
that would require the sustainable intensification
of the crop production systems,
such in a way that each hectare that we actually have,
produces close to its potential
minimizing the environmental impacts
and preserving the resources like soil and water.
So this is where the concept of yield potential
and yield gap comes into action.
So you can see here,
definition for the yield potential.
Yield potential is determined by the radiation,
the temperature, the CO2 concentration,
the cultivar, and the precipitation.
Soil is in the case that we are talking
about potentially dry land conditions,
and then we have what we call the actual yield.
That is the yield that the farmers are obtaining,
which is limited by poor nutrition,
poor management of pest, diseases, biotic stresses
and so on.
And the differences between these two levels
is what we refer as the yield.
Reaching around 70 to 80% of that yield gap,
is a reasonable goal for a producer with access to market,
technology and information,
Like here is a case of Argentina.
I will show these in the next slides,
and above the threshold performance increases
are more difficult and even not feasible
from an economic or even a logistic
or environmental perspective.
So we have been working in the Global Yield Gap Atlas.
This is an effort initiated by University of Nebraska,
and also by the team at Wageningen in Netherlands,
in collaboration with local experts.
In this analysis we will follow a specific protocol
based on knowledge of crop ecophysiology
and the production systems in each of these places.
I was in charge of, with the team from Argentina,
I lead the team in Argentina,
in which we estimate the yield gap for Argentina.
But let me before going to the yield gaps for Argentina,
let me use some background about the main crops
that we have in Argentina.
So in Argentina right now,
three crops account for more than 90%
of the total cropland.
And this number is even higher,
if we are thinking about the production.
Those three crops are soybean, maize and wheat,
they are cultivated,
soybean is cultivated around 18 million hectares,
6 million hectares of maize,
and around 5 million acres of wheat.
The yields that we have on average
are around three tons for soybeans,
seven tons maize, and around three tons for wheat.
And something that is very important for this presentation,
which I'm talking about soil nutrient mining,
is that most of all the grain that we are producing
is exported, mainly to countries in Asia,
and to other parts of the world.
But you know the crops,
the percentage of the production,
as export is very high and it's almost 100%
for the case of soybean.
If we look into the area,
how the harvest area had been increasing across the year,
we can see that there was like in the 90s,
there was like a sharp increase
in the harvested area in Argentina.
This was mainly at the expense of pastures
that were converted to crops.
Now we're experiencing some,
also some increase in the area,
but it's almost nil,
and another important feature of the yield in Argentina.
So, sorry here you have the area that you can see
with red dots and in green you can see the crop intensity.
We have around a crop intensity of 1.15.
That means that we have around 1.15 crops per year.
And this is mainly related
with the fact that we have soybean as the only crop,
that is planted after the harvest of wheat or more.
If we look into the yields,
you can see oil.
Here you can see the yields for sunflower and soybean,
as the function of the sowing here.
And in the y-axis in the right side,
you can see the maize yield,
all the years are increasing.
Argentina has one of the highest yield gain increases
in the world.
And also the winter,
the yield of the winter crops like wheat and barley,
they are always increasing at very high rates.
So another important feature of Agriculture in Argentina
is that around 60% of the acres is rented to their owners.
So that means that most of the year
is not produced by the owners of the land.
That is something I think quite similar
to whats happening here in Nebraska.
Around 90% or even a higher amount of the agricultural land
is under no-till system,
and it has been like this
for almost the last,
let's say the last 15 years at least.
Well, soybean is one of the main crops
around half of the area is occupied by this crop.
Another important feature is that around 65% of the area
of winter crops are double cropped with soybeans.
Something has been recently changing
is the amount of cover crops that we have.
Right now we have around 2%
of all the area with cover crops,
which might not seem like a big number,
but it's a big number in terms of hectares.
And that's increasing a lot from year to year.
So when we look into the yield gaps,
into the research that were done by, this was presented
by Fernando Aramburu Merlos in one paper
in yield gap research like this was in 2015.
So here you can see for the different regions in Argentina,
the yield gaps for soybean, wheat ,and maize,
for soybean we have a yield gap on average
across the country of around 30%,
and it's around 40% for the case of maize and wheat.
So we can increase the yield,
what we are talking about before, that we can reach
around 80% of the yield potential.
So that means that we can increase yields
by 10 points percent by around 20.1%
for the case of wheat and maize,
and 10% for the case of soybean.
So if we use the maize as an example
for the yield gaps across the different countries,
and how is South American comparison
to the yield gaps for other countries?
So you can see here in different colors,
the yield gaps in green colors,
we have very small yield gaps in black colors
the yield gaps are actual or maximum.
So there are some areas in the world
with very small yield gaps.
We have areas with intermediate yield gaps,
like you see the case of South America,
and areas in which we have a large gaps.
For the case of Argentina as I told you before,
we have intermediate gaps,
we also have a very good access
to market and technology and information.
And that means that we have,
like a very big,
a every reasonable opportunity
to close the yield gap in Argentina.
So one of the questions,
it will be what is behind that yield gap?
One of the main, one of the first things
that one may think about how to close the yield gap,
is, well we all know that to get high yields in any crop,
we will have a high or a large nutrient requirement.
So here we have an example for maize.
The scale having the grain yield for maize,
and the nitrogen uptake.
So this is an example for maize,
and using nitrogen as an example of the nutrients.
And you can see that when you got,
to obtain very high yields,
you also need to increase the amount
of that nutrient uptake.
And the soils typically that they do not provide
all the nutrients that the crop needs.
So farmers, what they do to provide the extra amount
of nutrients needed by the crops
to achieve their potential
is just they apply synthetic fertilizer,
or they apply other kinds of, let's say organic fertilizer,
like for example manure.
So this is where the nutrient balance comes into action.
So we also have here nitrogen, as an example,
when we talk about the balance,
we use the applied amount of nitrogen
minus the nitrogen that is removed with the grains,
and we can have two situations,
deficit or excess.
So when we have a deficit,
is because the nitrogen that is harvested
or removed in the grains,
is more than the nitrogen that we're applying
or when we have an excess
is because the amount of fertilizer
for nitrogen that we are applying
is higher than the amount removed by the grains.
In this example, we are using nitrogen,
but this example applies to other nutrients.
If we take a look into the most recent research
for nutrient mining across the world,
there are some examples,
like the one here I am showing you on the right side,
this is a map for phosphorus deficit
and phosphorus surpluses,
across different parts of the world.
As you can see, they indicate Argentina
as a place where there is a clear phosphorus mining,
this is another study in which they are measuring
the maximum protein yield of different countries.
And they're also indicating Argentina
and other parts of the world,
like parts where you have some nutrient mining.
These one has been at the country level
with very little data,
but they are indicating some nutrient mining,
especially for case of Argentina.
So this is where our question,
we have a question here,
is whether we want to go from yield gaps to nutrient gaps,
and for the case of Argentina,
if it is possible for Argentina to close
the exploitable yield gap in a sustainable way
with the current use of fertilizers
that we are doing.
So you can see here the map on the left side,
the map shows in this case the crop intensity,
in different colors for the maize crop.
And you can see in red dots,
each of these red dots is a collaborator
that provided us with data for yield,
and for nutrient use for each of the three crops
that I mentioned before with maize and soybean
across all the cropping systems in Argentina.
So we combine that information that was provided by ReTAA,
ReTAA as I told you before,
is like the research division
of the bona fides cereal board of trade.
They are collecting this data for every crop every year.
So they have a very detailed database
for all the crops across Argentina.
And we combine that information with a methodology
that we used before,
to estimate the yield gaps
in which we use different climate zones across Argentina.
Here, you can see an example for the case of wheat.
This is for the cropping season 2016/2017.
And here you can see that nitrogen rate
in kilograms per hectare,
the phosphorus rate, the sulfur rate,
and the actual yield
for each of these collaborators across Argentina.
So this information is the one that we used
just to estimate the rate across the country.
And then by using the actual yield
nutrient extractions per kilogram suffering
is how we estimate the nutrient balance for each crop.
We are only gonna see here
and nitrogen, phosphorus, and sulfur,
because potassium is a nutrient
that all the soil in Argentina,
they still have very high potassium levels.
So we are not expecting,
or we are not seeing so far
any widespread potassium deficiencies across Argentina.
So that's why we are only focusing here
on nitrogen, phosphorus and sulfur.
So, based on the data set I showed you before,
for three cropping systems
that go from year, 2016 to 2018,
2016, sorry, three cropping systems
that goes across these years.
We estimate the nutrient rates.
As you can see here,
the nitrogen rate for Argentina
for the case of maize is 59 kilograms per hectare per year,
around 12 kilograms per hectare per year for phosphorus
and around two kilograms per hectare per year for sulfur.
And there are also some differences here.
So this is also in kilograms per hectare.
But there are also differences across the different regions,
even climatic soils of Argentina,
for the main cropping regions of Argentina,
where we have the highest values for all the nutrients.
And when we move just forward the divisions
where we have the lowest nutrient rates
for the different crops.
Something that is important to mention
is that also in this specific part of Argentina,
we also have very high phosphorous content
in the soil so far.
So we still have enough phosphorus
just to keep mining this area,
but this is a minor area in comparison
to the most productive areas of the country.
When we take a look into the case of wheat,
we have something quite similar.
So 55 kilograms of nitrogen,
11 kilograms of phosphorus,
and 1 kilogram of sulfur,
with some differences across the different regions.
For the case of soybean,
and in the case of soybean,
we are integrating here the values
for soybean sown as a single crop,
and also as a double crop.
But for the case of phosphorus,
we have a phosphorus rate of, on average
5 kilograms per hectare per year,
and around 2.3 kilos of sulfur per hectare.
So this is the average across the country,
there is also here some differences
for the different regions.
We are only showing here phosphorus and sulfur,
and we are assuming that based on the most recent papers,
that is whether we have,
that the nitrogen balance can be assumed
to be zero for this crop.
Well, I showed you before the nutrient rates
across the country across different regions.
I am showing here the average yield
for these same regions.
So we have an average yield of 7.8 tons for maize
for those cropping seasons
in which we are working,
3.2 tons for wheat and three tons for soybean
with some, of course some differences,
that are related with the soil quality
and also with the yield gaps across the regions.
So when we use the average nutrient rate,
and we discount some grain nutrient removal,
based on some nutrient extraction rate,
occurring from IPNI,
so here you have different nutrient extraction rate
for different nutrients and crops.
So we arrive to these kind of maps.
So for the case of maize,
we have a nitrogen balance
of around minus 35 kilograms per hectare per year
across the whole country.
With some areas that even though they have very low yields
in comparison to the most important areas,
they also have very negative nitrogen balance
because of the very low amount of nitrogen that they apply.
We have phosphorus balance
of around minus nine kilograms for phosphorus,
and minus nine kilograms also for sulfur.
For the case of wheat,
the nitrogen balance is minus seven kilograms,
for phosphorus we have a zero phosphorus balance.
And for the case of sulfur,
we have a minus five phosphorus balance.
For the case of soybean we have across the country
minus 11 for phosphorus per hectare,
and minus seven kilogram per hectare for the case of sulfur.
So as you can see as I've been showing here,
so for all the nutrients,
we have very negative nutrient balances
for all the three main crops.
So here I show you the crops
but of course, if we try to combine them,
and if we take into account the area that each crop has,
the results will be just the same
because just combining all negative values will give you,
will you be a very similar result.
So how does this translate
into some of the nutrient balance
that we are observing right now in our soybeans?
So this is a work done by Sainz Rozas and part of his team,
working for institute of Argentina.
And so this map is for phosphorus.
So we are here,
I am here showing you phosphorus Bray.
And this map here is for year 2011.
And this is for 2018.
What they did here was they marked
different farms across all this region.
And they went back seven years before.
Well you can see the research,
you can see how all the phosphorus values
have been decreasing across the most important
and most productive areas of Argentina.
Which is a clear indication of nutrient mining.
And this is here an example for phosphorous,
but they also have the maps for all the other nutrients
which are showing a very similar data.
So, if we want to go from, let's say from nutrient gaps
from sorry, yield gaps to nutrient gaps,
or we want to estimate, what is it,
what is the current nutrient input,
and what is the extra nutrient input,
the requirement that we need to close the yield gap.
So first the current nutrient rates
are not sufficient as I showed you before,
to close a yield gap,
because they are even negative,
with the values that we have right now.
I know the nutrient balance
some soil mining in many cases.
So we wanna close the yield gap,
we will need to increase substantially,
the amount of fertilizer that we are using in Argentina.
So in this table you can see for each of the crops,
we have maize, wheat and soybean.
You can see the average yield, the attainable yield.
This was estimated based on world gap
I showed before of the yield gap for Argentina.
This is the current region rates that we are applying,
And this is the extra amount of nutrients
that we need to apply to close that yield gap.
And also we are taking into account,
the extra amount of nitrogen yield,
and to take into account any possible losses
of this nutrient
or for phosphorus and sulfur.
We are assuming just a replacement criteria.
As you can see let's say,
if we take a look for example,
for the case of maize,
we need almost to go from 60
to more than double the amount of nitrogen
that we are applying.
So we need to apply 59
plus another 119 kilograms of nitrogen
to close this yield gap.
If you may be familiar with, so this yield is quite similar
to the hours that you obtaining here
for the United States.
And the current nitrogen rate
that the maize farmers are using
in the United States around,
almost 200 kilograms per hectare per year,
which is quite close to the same value
that we have estimate for production.
And also we need just to also to increase the phosphorus
and the sulfur level,
and the same is happening for all the crops.(coughs)
Well, so far I have shown you all these analysis
that we have been doing mainly based on this database,
and some requirement mainly based on the nutrient
requirement just to achieve that yield.
But we have also some data with own farm validation
for what we are seeing.
So we have a database for different trials
in producer fields.
So these are not experiments that were done
in small pieces of land.
So they were all done in producer field.
They include 10 cropping seasons.
They are side-by-side comparisons
in which they have two treatments,
one in which they use the current nutrient rate,
that is quite similar to the nutrient rate
that I will show you.
This is the treatment that is called here, "PROD".
Because is the treatment
that the producer is doing right now,
versus a higher nutrient rate
that is mainly based on the target yield
or what we call the attainable yield
for each of these cases,
we call it here "NUT"
because it's high in nutrition treatment.
So we have those other for maize, for wheat.
And just showing here for soybean.
You can see here for comparison,
the values of nutrient rates used by the producers,
and the values that we were reporting on average,
which are quite similar.
There are very only very small differences,
and the nutrient rates that are used
in the nutrient treatment.
So we increase the amount of nutrients
that we are applying.
So if we compare these two treatments,
those are the graph that you are seeing here
on the right side.
So here we have the grain yield in milligrams per hectare.
And here We have the different field-year in number cases.
So in the yellow bars represent the yield,
obtained in the treatment with current fertilizer rates
used by the producer and the yield response
that is generated for the additional nutrient application
is shown in red here.
You can see here that on average,
an increase in the amount of nutrient
through higher fertilizer rate
is increasing the maize yield by 50%,
the wheat yield by 22%,
and the soybean yield by 13%,
which is very similarly equivalent
to close the exploitable yield gap
for all those crops in Argentina.
So we can, the main point here is that,
with own farm trials.
we are seeing that, is it possible to increase the yield?
We are increasing the amount of nutrients
that we are using right now,
if we want to estimate, okay.
what those nutrient balances means
in terms of nutrient mining in Argentina.
So I estimate here for the case of nitrogen,
phosphorous and sulfur.
the mining with the actual yield.
so we have a mining
of around 0.24 million tons per year.
So if we translate that into fertilizer,
so we will need 0.77 million tons of soybean,
of urea sorry,
just to get that amount of nutrient
that we are mining right now.
We also, I also did the same estimation
for, you can sit here for phosphorus
and the equivalent here in triple superphosphate.
Or the same for sulfur
and the equivalent in calcium phosphate.
I also here highlight in green,
for the case of potassium.
So this is the nutrient
that we are mining the most right now,
we are mining around 1.14 million tons per year
across the country.
That is equivalent to 2.3 million tons
of potassium chloride.
And of course, as I mentioned before,
we still have very high values
in all our soil for potassium,
but in the last two or three years,
in some provinces that have, let's say
the soils with the lowest potassium content.
We are starting to see some response
in the crops to an extra amount of potassium.
So that will probably start to continue,
you know, for all the other across the country.
But right now they use of potassium
in the crops is almost zero.
So you can see here,
what that means in terms for all these nutrients.
So we have a mining for the three main nutrients
that right now are deficient,
or of around 0.7 million tons
that translates into 2.7 million tons of fertilizer
to compensate for that nutrient mining.
Good news, is that,
well, the fertilizer use in Argentina is increasing.
So this is the current nutrient use
in million tons per year.
That has been increasing steadily,
but if we take into account the amount
that we need for a zero nitrogen balance,
Sorry, so we need to increase around 50%,
the amount of fertilizers that we are using
to achieve zero nitrogen balance.
And we almost need to double the amount of fertilizers
that we are using if we want just us to close the yield.
that there is something important just to mention,
is that one of the main questions
that usually are right here
or that I have been asked
when I present these in Argentina
or for Argentinian farmers or researchers
is well, if we have if we increase
the amount of fertilizer that we are using by that amount,
there might be some issues
as the one that you may be more familiar
with that are all the nitrogen loses
that we may have to the environment or phosphorus losses.
But it's just important just to show you some of them.
What the literature says about this.
And here we have the yield losses in both cases
as a function of the Nitrogen surplus.
So zero means like a zero balance.
So we are here, we're in the region
where we are mining the soil
and so any increase in the fertilizer use
that we can do where it's still very very far away
from any possible nitrogen losses.
Of course this is when we see the whole picture.
There may be some case in which these balances
are a little more negative,
or they are close to zero or a little bit positive,
but in general, across the country
we're still very far away from having any impact
on any negative impact of using
higher amount of fertilizers.
What are the take home messages?
First basis of on an increasing global food demand,
we have a competitive agricultural sector of Argentina.
We have also an intermediate yield gap.
So we are in an excellent position
to intensify the crop production
for the next 30 years,
The current nutrient rates that we are using,
they are NOT sufficient to close the exploitable yield gap
They are not even sufficient
for the current yields that we have.
And in many cases,
they are indicating nutrient mining in our soils.
And there is a reason period
where the areas that's already happened.
So any program that aims just to increase
the current productivity in our curbing system
in a sustainable way,
we will require from an explicit recognition
of the need, just to increase
the use of fertilizers in Argentina.
I just want to mention that I am presenting here
this research, but there are a lot of people here involved.
I would like to send to all of them
and especially to the people from ReTAA,
because they have such a data research,
that is was the one that made all this work possible.
So thanks to all of them,
I was sent to you and thank you for your time.
And now for this, I think we are open to questions.
-: I thank you very much Pablo
for this excellent helicopter view
about the nutrient balances in South America,
and also for not only you know, showing the problem,
but also elaborating on the solutions agenda.
So I really appreciate that.
So let's open now for questions.
In the meantime Pablo I have a question for you.
You, talk about, I mean to show the response to fertilizer,
but many prime, some of our colleagues here
are wondering if those responses
are economically profitable.
So can you talk a little bit about if those yield responses
also deliver economic benefits to farmers.
Still other people are submitting now other question.
So let's start with that one.
-: Yes, thank you for that question,
but as usually I forgot to mention that.
So based on, let's say on the, yes,
I think it was on the 10 year average
for the nutrient and grain prices,
on average for these crops,
the response was around two times.
So you get two times the money
that you are investing in the fertilizer.
So is it possible to increase the amount of fertilizer
that we are using and is it possible or profitable.
-: And do you remember about what was the ratio
between the benefit to cost ratio?
-: Yes, two times.
-: Two times, okay.
-: Well, Sorry.
-: Great, thank you.
Okay, there is a question here submitted by Thomas.
And is, could you please repeat the treatment
identified as NUT in their own farm trials?
-: NUT yes, so this is the treatment
in which we increase the amount of fertilizer,
and that amount of fertilizer was anxious
to achieve the yield potential
or the attainable yield potential
for each of their location.
In comparison, the nutrient rates
are used by the farmer or the producer,
and the nutrient rates that we are using in this treatment.
So in all the cases,
the new rates are higher,
and they are quite in line with the nutrient rates,
that we are estimating just to close the yield gap.
Except for the case of nitrogen,
I'm not sure here the balances,
but for this case,
the balances are a little bit negative.
So which means that maybe these rates
should be a little bit high.
And all these database,
and these other races from fertilizer association,
which is the fertilizer association in Argentina.
And they are also coming from Korea groups
that are, let's say like farmer organizations
or across the country.
So all these experiments are made on farmer fields.
-: So there is another question here from Authria,
and it's about nutrient losses,
and he's asking the following.
Is it applicable for this work
to discuss fertilizer technologies tools,
that can help to reduce
potential nutrient losses both applications.
So in a way, the question will be,
I mean, if I have to rephrase the question,
I will say, besides increasing nutrient rates,
is there a way to get additional yield increasing
by improving the efficiency in the use of fertilizer?
-: Yes, that's a good question.
Especially for the case of nitrogen,
in wheat and maize.
So I think the farmers are quite aware of that,
and especially in this year
with such a high nutrient prices,
But yes, pleading for sure is pleading
the amount of nitrogen that they're using
is one of the ways to increase efficiency.
And that sounds
you know that's yeah, it's a little bit different
from Argentina to here.
So farmers in Argentina,
they mainly apply nitrogen once they sown the crop.
So most of the applications of nitrogen,
they are at sewing or at the B6 or BH stage for maize
and all the application for nitrogen,
most of the application for nitrogen
they are also after the wheat is sown.
And so there is, I think a very combination
between when the nutrients are applied
and when they are uptake by the crops.
-: So again, that the answer to that question
is that yes, there are ways
to improve the uptake efficiency.
-: Yeah, but I think that that will be more important
once we reach the nutrient rates that we are targeting
in this world or so.
-: Okay great, thank you Pablo.
All right, so the reason I questioned
about the NUT treatment
in this where you increase the MPNs
in the NUT treatments,
and you clearly show
that yes, the MPNs was increased in the NUT treatment.
-: Yes.
-: So we don't need to go through that one.
So then there is a question from Aconsado
who is very nicely complimenting your presentation,
but then, he's kind of criticizing your conclusion
about the, you know, that there is no reason
to worry about the environmental impact,
given even the current level of application.
And he's interested,
well, he's asking
kind of a one million dollar question there,
because he's asking for environmental thresholds.
So he's asking you to elaborate
a little bit more about, you know,
how much we can push nutrient
for this application while keeping
the negative environmental impact, precisely low,
-: Yes okay, I will try to,
so let's say we are reaching a zero balance.
That means that the amount of nitrogen
that we are striking within grains,
It's similar to the amount that we are applying.
So and in that case,
we are not taking into account
other nitrogen losses
because we are just taking into account for this analysis,
the amount applied with the fertilizer,
the amount extracting with the grain,
the amount removed with the grain sorry.
So if we also take into account,
let's say the amount of nitrogen
that is lost and the amount of nitrogen
that we also need
just to maintain the soil organic matter levels.
So that means that we would probably have to be more close
to a nitrogen balance between 30 to 50 kilograms
to a positive nitrogen balance between 30 to 50 kilograms,
just to, let's say, to maintain the soil organic matter.
And just to add all the nitrogen
that would have been removed with the grains.
If we all just let's say like below or above that threshold,
that is where the amount of nitrogen
that we are losing in other forms.
They will start to increase.
Though I think that that value
will be like a reasonable value.
There are may be you can say something over these,
but the ratio that you have in mind
they were done by Fatima Tenorio
that I think he's reaching some similar conclusions
regarding that threshold.
-: Well, that's a very good question,
but thank you, yes.
The work of Fatima shows that, you know,
nitrogen losses per unit of yield
are fairly low until an energy imbalance
of plus 70 kilos of nitrogen per hectare.
And above that threshold,
they start to increase exponentially.
So if you for a farmer
who is within I would say 20 to 50 kilos
of nitrogen balance that's a kind of a safety zone to be,
because we know that within that range,
you can maximize here,
but at the same time and then they yield
the nutrient loss is fairly low.
-: Fairly low yeah.
I do have another question here from me,
when I'm waiting for others to submit
theirs it's about, you mentioned many points
during your presentation
that for example in the case
of Phosphorous was the you know there was net mining
in some areas like in the Northern region,
but however there was no reason
for concern and leave for now
because those holes the north are kind of new
for agriculture and therefore they still have
high levels of phosphorus.
And therefore you cannot know until they become limiting.
And then you brought this to the whole country
in the case of potassium
you in which you indicate
that given the young nature of their social media
you can allow some mining until you see
some indication of deficiencies
as you indicated it is the case in recent years.
So in relation to these kind of mining
that is okay for now
what I mean, can you elaborate a little bit
about what will be your efforts,
your longterm strategy to deal with them,
and what would you suggest to deal with them
to try to anticipate that and already start to apply
a little bit of nutrients to try not to get
to an deficiency level,
or you will simply let both soil
to be mindful potassium and think you're starting
to see the deficiencies
and then maybe you know,
implement a plan of simple replacement to deal with them.
What would you gonna do?
-: That's a good question.
But I think I will answer that question
just with a farmer mind and with a farmer mindset.
And what we are observing here is that nitrogen
is so deficient, phosphorus is so deficient.
So that I think that we are initiating a picture
for the whole country let's say.
we should focus on increasing
the amount of nitrogen, phosphorus and sulfur
that we are using
and we can keep mining some potassium and some phosphorus
in some parts of the country
till they start to become limiting for the crops.
Because as I shown you before.
So the amount of for example of nitrogen
that we have to increase, just so high.
That just to tell the farmers also to take into account
one of the nutrient that is not already limiting,
I don't think that is gonna be easy.
So I think it's easier at this stage
just to concentrate on those nutrients
that are very limiting right now,
and to start increasing those ones.
And then we can start with the other ones,
but I won't worry too much
about potassium right now in Argentina.
Only in a few areas it is starting to be limiting,
but I will worry more about nitrogen and phosphorus.
That is clearly limiting the yields
that we have in our crops.
-: Well, I guess I message for everybody,
that Pablo is trying to translate
is that we should look at this from a plant perspective
rather than a soil perspective, all right.
-: Yeah the economic perspective and soil also.
-: Ready to wrap up for today,
I wanna thank again Pablo for your excellent presentation
about the nutrient balances in South America.
We also want to thank the people who submitted questions,
and as always, if you have any follow-up questions,
feel free to contact Pablo,
and thank you very much.