Welcome back to the course in nanomaterials
in agriculture, so as of now I have talked
you about the different kind of nanomaterials,
the morphology, the structure followed by
the synthesis techniques and then the characterization.
And earlier to that we have talked about the
overall situation why there is a need or there
is an extreme interest about using nanomaterials
in agricultural products.
So now we were shift gear and we will move
to the practical application of nanomaterials
in agriculture.
So, if you recollect the one of the slides
which I talked pretty early when I started
the course is using nanomaterials in agriculture
and there we talked about where all nanomaterials
could be used where it could be used into
the soil directly or it could be used in the
plant body.
And at different stages of the plant growth
or it could be used into animal feed or injecting
the animals or for skin patches.
Now when we talk about putting a nanomaterial
into the soil we are essentially talking about
the resources like water, soil will be under
the influence of nanomaterial.
So that is something which we have to realize
or appreciate or understand that exactly what
happen in fertilizer should not get repeated.
So, to ensure that the nanomaterials what
we are using or benign to consumption if at
all the residues remain or gets degraded over
period of time.
So, whenever we talk about the soil we are
directly talking about the water bodies and
that is where some of the purification things
nanomaterial to purify water that is what
will be discussing under this topic where
there is a lot of research going on 
water purification using nanomaterial.
Now talking about direct applications into
agriculture either it could be used to different
parts of the plant body.
Either for the root treatment or shoot treatment
or foliar spray or floral spray as well as
something which I have mention earlier is
seed treatment.
So, starting from the seed which is like the
dormant part of the growth to the root treatment
or root priming depending on what kind of
routes we are talking about all the way to
treating the shoot as well as the foliar spray
all the way to the flowers.
Now in the case of animal especially it is
use for animal productivity in terms of either
milk production or meat production it could
be used as a feed additive.
We talk one such example where there is a
hope with 1 of the nanoparticles or they could
be injecting for immunity or they could be
used as a skin patches for slow release.
The overall goal of these kind of application
is enhancing 
productivity both plant and the animal world.
Apart from it there is tremendous thrust of
applying nanomaterial for post-harvest technology
which includes food preservation mostly this
includes grain and fresh produced preservation
which includes of course cut flower preservation
and all the kind of other off shoot areas
into the field.
So, to start off with I will start off with
seed treatment agent as nanomaterials.
So, nanomaterial to improve plant/crop productivity
by seed pretreatment.
So, to start the 
topic seed pretreatment in other word farmers
before showing the plant or before showing
the seeds, they do treat the seeds.
They treat the seeds in different ways, they
can either use different kind of fungicides,
they can use different kind of a germinating
agent which will promote faster germination
or they can be use some other kind of growth
booster to ensure the seed germinates.
So as a matter of fact, the success of any
crop depends on the germination percentage
higher the germination the better the crop
standing and on all like we have the all other
parameters may incurred than higher will be
better crop standing better higher the yield.
So, this critical part is extremely important
than formers have been using to enhance germination,
they treat the seeds with different kind of
thing.
The major treatment they do possibly is the
water treatment or overnight treatment in
water apart from they use different kind of
fungicides, germination booster 
or any other kind of you know agent which
will help it to strengthen its immune system,
strengthening immune system.
Now for the simplest of all the things water
treatment what the water does.
So, if you look at the seed it is something
like any series like this.
The seed coat and inside is the real growing
material is preserved inside.
Now the seed coat is mostly impermeable to
water, it does not allow water or any other
things to pass through so easily.
So, when it gets an overnight treatment with
water slowly the water molecules kind of enters
inside period of time and activate the metabolic
processes.
So, the next morning so this is metabolic
processes, so the next day the germination
vigor 
is more.
So, this is an agual practice what farmers
have been following through centuries since
possibly dawn of civilization and it will
continue till the dusk of civilization.
These are very very common methods similarly
farmers use some kind of a coating of stuff,
so this red is ideal coding or some kind of
germination booster or some kind of immune
molecule which ensures once the plant gets
into the soil.
So, once the plant is into the soil there
is enormous competition 
from microbes who are compete in for food
from other seeds of the same family as well
as from the other families and from different
insects and other pathogens.
So, a life of seed soon after it gets into
the soil is really treasures one, it really
tough because the life has to express itself
and that is very challenging.
As a matter of fact, in that competition to
germinate the one which will win is the one
which will make a mark, the one which will
fail to germinate will lose this battle.
So now keeping this in mind one of the easiest
approaches of applying nanomaterial could
be seed pretreatment agent.
So, once you are applying in to the seed,
so whatever you are trying to do has to be
the overnight stuff and ensuring that these
seed pretreatment agent are doing something
after coming in contact in that millue.
So, whenever we are treating, so there could
be 2 kind of treatments you do either it could
be a dry coating of nanomaterial on top of
the seed dry coating of NM stand for nanomaterials
or there is some kind of an aqueous treatment.
Aqueous treatment is basically nanomaterial+water
that is how you are treating.
Now today I will be sharing one of the stories
of this second treatment aqueous treatment
when nanomaterial+water and where it acts.
So, our first journey will be with one of
the metal sulfide nanomaterial and this is
possibly one of the very very first nanomaterial
base seed treatment agent which I have shown
profound impact on at least 10 or 12 different
crops by increasing the productivity to the
level it has ability to compete with the fertilizer
applications.
So, the metal sulfides here the metal iron,
sulfide is S, so compound what whose nanomaterial
we were dealing with will be FeS2 which is
also called pyrite or crushed is rich very
rich in pyrite.
There is huge amount of pyrite all over the
crush especially if you go to the places like
close to the coal mines or you visit places
like where you really see a huge amount of
it is rio, tinto river valley in Spain or
there is another place where there is a rich
source of pyrite apart from the pyrite mines.
There are lot of pyrite mines all over you
will see huge amount of pyrites in deep inside
the earth into the hydrothermal vents.
As a matter of fact, pyrite is also called
as fool’s gold, the reason it is colloquially
called as fool’s gold because the bulk pyrite
is golden in color.
And that is why many a times people mistake
it as a gold that is why it is called as fool’s
gold.
So, pyrite is a very interesting compound
which has find applications in myriad or places
like in terms of agriculture bulk iron pyrite
is being used in sodic soils, reclaiming sodic
soils.
Say for example a soil which is sodic or pretty
high pH like say you know 13, 14 or something
we can bring down the pH by to 7 which is
a physiological pH by applying FeS2 or pyrite.
Because once FeS2 gets into the soil in the
presence of moisture it generates sufficient
number of protons which brings the pH.
So, for reclaiming sodic soils pyrite has
been used especially in Indian context if
you talk about.
And such reclaim sodic soil has shown pyrite
application into the soil 
in sodic soil improves nitrogen availability
to the crop.
Especially this has been observed in the rice
crop but a challenge of using pyrite is pyrite
brings down the pH.
So, a normal soil can become acidic or will
become acidic or has destined to become acidic
if you use bulk pyrite into the soil, so keep
that in mind.
And there are certain trials which are done
in Kanpur back in 1970’s, so this is what
I am talking about is around 1978.
So, almost 40 years back, these kinds of research
happen in India but there was nothing called
nano or anything.
Apart from its pyrite is one of the very extensively
study material in of photo volatile and semi
conductor.
For semiconductors application these were
used as rectifiers as early as 1910 to 1930.
This time when these pyrites where used as
rectifiers and it has tremendous photo voltaic
potential if it could be exploited for the
solar cell applications.
So, pyrite is nothing new to us, pyrite is
a fairly old molecule through the ages and
as a matter of it is being claimed that if
pyrite could be used as a solar cell material.
It will be far more efficient than crystalline
silicon-based system because it tends to absorb
in far red region.
So, this is one of the key reasons why there
is tremendous amount of interest in nano iron
pyrite starting from electronics to photo
voltaic all the way to reclaiming sodic soil.
It is found tremendous application but it
comes with a small drawback, it suffers from
something called stoichiometric defects.
So, we will continue with what is the meaning
of stoichiometric defect and from here we
will go down all the way to the deep deep
into the dark world called hydrothermal vents.
Because from here started our journey of it
is application a new application of brand-new
application of nano pyrite which was never
discovered earlier the first time it is discovered
in India was as a seed treatment agent, thank
you.
