Translator: Agustina Apricano Reviewer: mariana vergnano
This image may look familiar for people from Bahia Blanca.
This is the dike Paso Piedras
in 2009, when Bahia Blanca was suffering from
one of the worst droughts there has been.
During that time,
we were all worried about whether or not the dike had water,
if it had gone up 1 cm
because we didn't know if the next day, or the next week,
we would have water coming out of our faucet.
It is from here that the cities of Bahia Blanca and Punta Alta
get what we'd call running water,
because calling it "drinking water" would be controversial.
At that point, I got used to checking, everyday, the dike's water level
in the public authority's website.
I remember we got to 154 metres and 45 centimetres, something like that.
We can see the water extraction here.
They were already taking out water with mud.
It was a pretty stressful situation for all of us.
Around that time, I had the opportunity to travel
to a conference about water and renewable energies in Cordoba.
When we got down off the bus there,
and went to the toilet in a service station,
there was a little sign that said: "Please save water."
We got to the hotel,
and in the bathroom, we found the same thing.
In a hostel, in the kitchen, the same sign.
Everywhere a sign said: "Please save water."
Why?
They were going through an important crisis as well.
Through a water crisis the size of Bahia Blanca's.
So, well,
it gets you thinking: the water crisis is not nearly something local.
And not from Cordoba either.
They were not the only two cities in the world going through this crisis.
Australia was too,
their fields were disappearing, they had no rain, no water.
We were going through a pretty critical moment
at the global level.
And that was like a slap in the face for all of us
because we realized that fresh water isn't an inexhaustible resource.
On the contrary, it's finite and it has to be used carefully.
Very carefully.
A couple of months ago,
I was lucky enough to participate in an excellent interdisciplinary group.
To participate in a competition.
We had to research how much fresh water was used
to dilute a certain herbicide in all of Argentina's fields.
I'm talking about just one weed-killer, one herbicide, in the whole country.
We found that you need 29 billion liters to dilute it.
It's a huge number.
It's very hard to realize what all those zeros mean.
To give you an idea,
think about how much water you use a day.
From the moment you get up with a sleepy face
and you have to wash your face,
your teeth, you take a shower, you have a cup of coffee,
one at home, one at work,
then you cook, you boil some pasta, some rice.
Which is more or less my diet.
And then you take a nap, you wash your car,
you have to bathe your dog that made your whole house dirty,
you have to clean your house.
Well, how many liters of water do you use in one day?
Now multiply that by the 365 days in a year.
And now multiply that by 650 thousands
which is around how many people live in a city
50% bigger than Bahia Blanca.
The amount of water a whole city of 650 000 inhabitant consume in a year:
29 billion liters of fresh water.
So we thought there was a problem there.
An important problem.
And we said ok, let's see what can we do to save that water
that can be made into drinkable water,
and then we could drink the water that is being used.
I'll tell you a little bit about what is done in the countryside.
When you harvest,
there are some remains of the harvest,
—pieces of dead plants that are left on the ground—
After that, weeds start appearing,
which we don't harvest, the weeds.
Before sowing again, that has to be killed.
How is that done?
You don't just send someone to rip-off all the weeds,
because then it would take us ten years to start sowing again.
So we put a very powerful herbicide.
But you don't buy the herbicide all prepared and ready to use.
No, it comes very concentrated,
in a liquid and sometimes even grainy, solid.
So you need a whole lot of water to dilute that.
What do they do?
Well, they mix everything up in a container,
they grab the sprayer,
which is why you may have found mosquitoes in the highway,
and they spread it evenly all over the field.
That's not a very good technique, why?
Because weed doesn't grow evenly in the whole field.
It grows a little bit here, another plant over there
and another one 5 metres over there.
This weed killer works when it is in contact with the leaves.
What about the product that is just thrown on the ground?
It does nothing.
It's a wasted product.
It's water that was squandered,
fresh water that could have been drunk, wasted.
But now, since it's mixed with some chemical,
a herbicide, it cannot be drunk anymore.
So we thought: well... how can we save water?
What if we sprayed this diluted herbicide only where the weeds are?
That'd be great.
But in order to do that, we first have to make a weed sensor.
It has to be designed.
And that's what we started doing.
We designed a little system
that is attached to the existing machines.
This means you don't have to buy some huge machine,
spending lots of money.
Instead, it is something relatively accessible,
at least to be done,
that would get attached to the existing machines.
It's a sensor that controls the sprayer mouthpieces electronically.
So the sprayer comes with its arms wide open
and a sensor says "look, there's a weed."
So it starts thinking: how fast are we going?
What is the wind speed?
How big is the plant, approximately?
And where is it?
Well, ok, so I have to open this valve at this moment
for about this amount of time.
It has to calculate all that very quickly
because from the moment it registers the weed
until the moment when it opens the valve,
just some thousandths of a second go by.
So we are saying that it has to make
all these calculations in thousandths of a second,
in micro seconds, we could say.
All that takes important development.
But the idea was to add something to the machinery we already had,
That's how we realized,
looking at the figures, which we love.
The rest of the group. Not me.
Even though I studied physics, I don't like numbers, believe it or not.
We found that we saved 60% of the water.
What does this mean?
Billions of liters of fresh water.
That's what we're saving
with a system based on a pretty simple principle:
detecting where a plant is.
Everything underneath that is complicated,
but there's people who study to do those things.
And think about it: a principle that is just detecting a plant
allows us to save billions of liters of fresh water.
I'm sorry if I'm being repetitive, but this is extremely important.
These numbers, we drew this percentage at a national level,
just so it is clear how important it is.
And we said:
if we're going to add something to the machinery
that is worth about a million pesos
we might as well include some other functions too.
So we started studying
and we realized that with our mechanism to detect plants
we could also detect how healthy our plantation is.
Suppose we have a plantation of soy.
Then, we have to spread a pesticide,
we have to kill every worm.
That is spread across the field.
And at the same time, without adding any effort,
we're scanning how the plants are doing.
So look at that:
we spread it over this field and there are some red zones.
What does that mean?
That soy isn't growing the way it should.
I's hydraulically stressed.
Why might this be?
Because it lacks water,
because it lacks some kind of mineral,
because it's being attacked by some disease,
because someone has set it on fire.
Could be because of anything.
So the tractor operator finishes its tour, takes the map
and says: "Oh, no! the soy is not growing well over there."
So he calls the agronomist and tells him
"Hey Tito, can you come by the field? There's something going wrong."
So the agronomist comes, takes a look at the map and says,
"There's something wrong in this area, in these coordinates."
He goes to that area in particular
and examines the plant, and the ground as well.
That way he can determine: what's missing here
is more magnesium,
more potassium, more of a certain chemical, fertilizer or whatever.
"The earth is very dry over here, you didn't irrigate it!"
So this way, you can provide
a better orientation for the resources you have for the field.
You won't think "I must spread the fertilizer all over the place."
No, I must pour fertilizer, a certain liquid fertilizer,
on a certain spot.
And every agrochemical needs to be diluted with water.
Therefore, we are also saving more water.
We didn't calculate that amount of water, because each field is different.
That is individual judgment.
We didn't do the math there.
Well, so we ended up creating a system
that brings happiness, not only to the farmer,
because he will improve its efficiency,
but also helps the plants, because they will all grow healthily.
It will bring happiness to Tito, the agronomist
who no longer has to walk over the whole field like he used to
in order to examine every plant, right?
I told you I was lucky enough
to participate in an interdisciplinary group.
This is us.
We had 23 hours in that contest to come up with this solution.
And a fun fact is that, of all nine of us,
just one has a real title
that is the Master of Engineering Santiago Maiz
who's sitting right there.
The rest of us, we are students.
Three students of Industrial Engineering,
three of Mechanical Engineering,
and two of us, we are students of Physics.
Now, notice how a single idea, how the seed of a contest
sowed an idea that could save billions of liters of water.
I will leave you with an idea,
the same idea this contest left us with.
What if the private sector posed its ecological, economic, and technical issues
to the people in general?
We got to this by taking part in a contest
that we saw a sign for at our university.
But it could have easily been public for everyone.
Because the solution for a certain problem doesn't have to be just in the university.
It may be.
Because there are people devoted to thinking there.
But anyone can come up with something.
Even if it's a technical issue, any of you can come up with an idea.
We just have to make sure these problems get to the general community.
And I just wanted to leave you with that thought
because it’s really something we noticed was missing.
That's all.
(Applause)