Microbes in bio-fertilizers Video Lecture | Advance Learner Course: Science Class 7

hello friends this video on
microorganisms friend and four part 12
is brought to you by exam showed calm no
more fear from exam so now we will see
how microbes are useful as
biofertilizers now before make up about
micro genes as by fertilisers first let
us try to understand what are
fertilizers and why do we need them now
fertilizers are those substances which
are added to enhance the fertility of
the soil now if we want to grow crops if
we want to increase the crop
productivity we need to ensure that the
soil is fertile enough so that the
plants which grow on that particular
soil and get all the required nutrients
minerals and thus can give better
productivity now adding fertilizer it is
just like externally adding more and
more nutrients to the soil so all
phosphates and nitrogen can be added to
the soil by fertilizers so these
fertilizers result in higher yields and
healthy plants because they directly
increase the nutrient content of the
soil now there are certain disadvantages
associated with chemical fertilizers now
some of these are the chemical
fertilizers and basically chemicals so
they are basically made up of harmful
chemicals which can be harmful for other
life forms even though it increasing it
is increasing the soil fertility but it
can be harmful for so many living
organisms present inside the soil for
example earth warms other small insects
which live in the soil they might be
harmed if this toxic material is present
inside the crops and if the crops are
eaten up by other animals it can cause
harm it then it can cause imbalance in
the soil pH so the acidity or basic
nature of the soil can get disturbed due
to the presence of lot of chemicals
results in soil in fertility though the
purpose of fertilizer is to increase the
soil fertility
but if fertilizer is applied to the soil
in excess in that case it can spoil the
soil fertility because too much of
chemical substances in the soil will
also spoil the nature of the soil the
breeds ecosystem because then it is a
toxic material it can kill many life
forms of the soil ecosystem
therefore this why we ko system might
pick disturb lands become susceptible to
many diseases sometimes what happens is
if the plan if these kind of party is
the same type of fertilizer is being
applied over and again very frequently
and in high amount so sometimes the lam
become very much used toward those kind
of fertilizers do not work for the
plants so the plan is instead of growing
better they tend to get diseases fruits
and vegetables have higher toxic
residues as I said now since these are
toxic materials there are chances that
they might remain somewhere inside a
fruit or a vegetable so when that fruit
or vegetable is being eaten by some
other animal it can cause some harm with
that animal environmental pollution
if fertilizer is used in X's and
immediately after fertilization if the
field is watered either by rain or by
irrigation so there are chances that the
fertilizers might will get washed away
by the water and it test it can cause
water pollution to the nearby water
bottles maybe the nearby pond or the
nearby river might get polluted because
of this toxic substance which might get
washed away by water so these are some
of the disadvantages associated with the
use of chemical fertilizers and all
these these advantages are because of
the poisonous nature of these chemicals
so we can say that the fertilizers and
advantages in terms of that it increases
the fertility of the soil but at the
same time it is not eco-friendly so it
harms the environment
the same time so therefore was
introduced by a fertilizer so viral
fertilizers are like living organisms
which act as fertilizers so these are
basically living organisms so they are
not chemicals so they will not cause any
harm to the environment so they will be
eco friendly but at the same time they
will act as fertilizers that is they
will provide nutrients to the soil so
they will enrich the soil fertility so
that means it will have all the
advantages of fertilizers but it will
not have the disadvantages of
fertilizers so these are living
organisms which enrich the soil nutrient
quality the source of bio fertilizers
are bacteria fungi and cyanobacteria all
these microbes they help to increase the
nutrient core quality of the soil so let
us look at some of the examples of
biofertilizers now one good example is
the nitrogen fixing Rhizobium bacteria
so there is this bacteria called
rhizobia and where do we find it we find
it in the root Claude rules of lay you
in this plants the water leguminous
plants plants like beans peas they are
all they all fall under the category of
leguminous plants so if you look at the
roots of these plants you until you see
that there are these nano structure and
because of these these nadu length
structures so in these root nodules are
present these bacteria called rhizobia
so this is a symbiotic association
between the Rhizobium bacteria and the
root nodules of legumes plan i want to
symbiotic association it is basically an
association there both the parties get
benefited so one party is Rhizobium
which gets its shelter and food from the
roof modules and the other party is
this route module of the plant so how is
the client getting benefited because
this bacteria helps to fix atmospheric
nitrogen into the soil so now if the
soil has more nitrogen who will take the
benefit out of it the plant of course so
the plant allows ice OBM to stay in its
root nodules because this bacteria
brings nitrogen to the plant and
nitrogen is a very important nutrient
for the plant so the plant needs it at
the same time the bacteria's advantage
is that it gets its food and shelter
from the plant so this bacteria fixes
atmospheric nitrogen and therefore
nitrogen being an essential nutrient for
the plant so we can see that it
increases the nitrogen content in the
soil so basically this ishow bein
bacteria acts as a bio fertilizer
because it is increasing the nutrient
content or the nutrient quality of the
soil so this was one example let us look
at the next example it is again a
symbiotic association so let me write it
here symbiotic association is an
association where there is mutual
benefit so here again this is another
symbiotic association between fungi and
certain plants so this type of
association is called mine or Visa or
mycorrhiza
so this is the name given to this type
of association between fungi and plants
now how the fungi help shed here so here
in this picture you can actually look at
the microns of root tips so here you can
see they have not UNIX structures right
there chips see here some fungi are
present and these fungi they absorb
phosphorus from the soil and pass it to
the plant so that means it helps to
implicate the act as bio fertilizer
somehow because they help to increase
the nutrient quality of the soil and it
helps
passage of phosphorus from soil into
them slams it in another symbiotic
association so this is resistant to
pathogens also it prevents the attack of
disease-causing microorganisms so that
means also it is beneficial to the plant
therefore it ensures better plant growth
and development so this also acts as a
bio fertilizer to the plant because it
provides a macro nutrient that is
phosphorus to the plank and Rhizobium
provides nitrogen to the plant both
nitrogen and phosphorus they are type of
macronutrients very very important
nutrients for plant growth and
development the third example is
cyanobacteria which are also called as
blue-green algae
these bacteria are also called as
blue-green algae they also have been
fixing atmospheric nitrogen and thus
they add organic matter to the soil so
some of the examples of cyanobacteria
like anabaena
know stuff they are examples of
cyanobacteria which fix atmospheric
nitrogen into them so I so these are
examples of some microorganisms which
help to fix nitrogen or phosphorus into
the soil and their food act as
fertilizers but at the same time they do
not have any disadvantages of chemical
fertilizers attached with them therefore
it is completely beneficial so we get
the benefit of fertilizers at the same
time we do not have any risk to the
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