Lecture 40: Compost

Welcome guys into the, in this last lecture
of week 8 of Soil Science and Technology. And will be trying to finish this soil organisms
and then will be covering some basic aspects of composting and vermicomposting. So, let us start from the fungi. Now, fungi is another important soil micro
flora. It is a smallest achlorophyllous plant I would
say and fungi are the filamentous organisms with much larger cell width than that of actinomycetes. And the filaments are called hyphae and the
network of hyphae is collectively termed as mycelium and the hyphae may be divided by
cross wall called septa, while those without septa are called coenocytic and predominantly
multiply by sporulum sporulation. So, some important genera which are frequently
found in soils are Pythium, Aspergillus, and Penicillium and then, you know, Verticillium,
Alternaria, Fusarium and all this things. So, they are mostly heterotrophs and they
grow basically within the dead bodies and, you know, dead organic matter they thrive
on dead organic matter and some fungi are responsible for causing the plant diseases
also. So, you can see here aspergillus very important
very important fungi soil fungi. Now, what is the role of soil fungi? So, fungi primarily responsible for the decomposition
of organic matter and also the deposition of organic matter it is basically it should
be read as decomposition of organic matter and some fungi form a symbiotic association
we have already covered that symbiotic association we call it mycorrhizal association and guys
we have already covered this VAM thing in our phosphorous lecture. So, the association can be divided into, you
know, that 2 types that is ectotrophic mycorrhizae examples are Boletus and Amenita and VAM that
is basically orbuscular mycorrhizae examples are glomus and endogene. So, these are some examples of ectotrophic
and endotropic mycorrhizae and basically you know that they increases the availability
of the insoluble nutrients to the plants and also increases the mobility due to the faster
intercellular nutrient mobility. So, that is why these fungi are very very
indispensable for maintaining the soil fertility. Now, let us let now next, let us talk about
algae, algae you know chlorophyll containing organism which are basically autotrophic and
the soil algae they classified based on their colour, there are 4 major classification. One is called Cyanophyta. This is the most important or these are also
known as blue green algae. These are important from the point of view
agriculture point of view because, they synthesize the, you know, they are important for biological
nitrogen fixation, the other groups are Chlorophyta which are grass green algae, Xanthophyta they
are yellow green algae and Bacilliriophyta which are golden brown algae. Now blue green algae, you know, that they
can fix nitrogen in rice field and it can supply oxygen to the aerobic organism in the
flooded soil as it has photosynthesising capacity also. So, also they synthesize plant growth promoting
hormones. So, the common genera in the soil are Anabaena,
Nostoc and Tolypothrix, you know that Anabaena azollae is an important algae which is responsible
for synthesizing atmospheric nitrogen or, we know, fixing atmospheric nitrogen in the
rice field and these are also very very helpful and very very important from the agricultural
point of view. Now, next important let us talk about the
soil micro fauna, protozoa let us talk about protozoa. They are basically single cell organisms however
the life cycle consists of 2 phases; one is the actively growing phases that is multiplication
and secondly the resting phase, that is where they form cyst like structure in adverse environment
to protect themselves and they can be classified on the basis of the locomotion. So, some moves by long whip like structures
like called they are called flagella and others by short hair like structure called cilia
and others by internal protoplasmic movement forming flexible temporary organs call pseudopodia. So, these, you know, based on these, they,
you know, they are classified, so you can see in the right side there is a flagellated
protozoa you can see and they generally help in organic matter decomposition as well as
because they are saprophytic in nature and also they can feed on bacteria and maintain
biological equilibrium in the soil. The next important microfuana are Nematodes
and among these are and they are they are they are next to protozoa in abundance and
because of the narrow long bodies, they are also called threadworms in this and they are,
you know, they may be saprophytic or parasitic in nature. So, they do not have any significant role
of organic matter decomposition, but they are responsible for many diseases in the plant
as we can see here, they are some, these are some nematode which are present in the plant
and this is one of the major plant disease called root knot disease which is created
by this nematode and they mainly infest the plant roots and form this characteristic knots
in the roots and most of the time vegetable crops are mainly susceptible for this type
of nematode attack and to reduce the infection, different types of chemical fumigants and
non edible Neem and Karanj cakes and, you know, nematode trapping fungi are basically
used. So, basically nematodes does not have any,
I would say, a beneficial effect on soil, they are mostly, you know, parasitic and they
mostly create some diseases in the plants. So, we need to take care of these nematodes
and we need to eradicate the nematodes for the better growth of the plant in the soil. Last one is the Viruses, now viruses are the
smaller than that a bacteria and cannot be seen by ordinary microscope and they do not
have any role in the nutrient transformation only they are parasitic in nature and these
virus which basically parasitizing bacteria known as bacteriophages you know that from
your plus 2 knowledge. And if the population of the bacteriophages
increases it will hamper all the activity done by bacteria in soil like nutrient transformation
nitrogen fixation etcetera. So, this is a structure of bacteriophage you
can see their capsid head which contains the nucleic acid or DNA and then followed by collar
and sheath and then base plates and then spikes and tail fibre. So, this is a structure of a bacteriophage. Viruses are also very much abundant in the
soil. So, guys we have completed these soil organism
lecture and let us go ahead and start another important topic or the last topic of this
week that is compost. So, what is compost, compost is basically
an end product of composting. So, what is composting you can ask. So, composting is a basically decomposition
of plant remains I would say control decomposition of plant remains and other once living animal
materials to make an earthy, dark, crumbly substance that is called compost and that
is excellent for adding in house plants for enriching garden soils. So, this compost is basically a, you know,
it is decomposed organic matter which contains high amount of nutrient and people generally
use this compost for their, you know, everything different types of garden crops and, we know,
different types of vegetables and there are several types of composting methods and composting
is one of the major soil organic manure. Now, why we should use the compost the question
may come. Now first of all, since it is a high amount
of organic it is a another it is a basically an organic matter which we are basically adding
into the soil, compost improves the soil structure, texture and aeration and it increases the
soil water holding capacity. Obviously, since they are having high amount
of organic matter, they are increasing the soil structure and their aggregates and also
their aeration by improving the soil structure and also they are improving the soil water
holding capacity. Because, you know that organic matter contains
huge amount of micro pores which can hold a huge amount of water and also compost loosens
clay soils and help sandy soils to retain water. So, if we add some compost into the sandy
soil, the water holding capacity of the sandy soil will increase, whereas if we add organic
matter into the compost into the clayey soil which is hard in nature, it will loose it
down and it will help in better water movement and air movement. So, this is the benefits of using compost
into the soil and also it improve soil fertility and stimulates healthy root development and
organic matter which is present inside the compost provide foods for microorganisms like
nitrogen, potassium and phosphorus mineralised. So, these are a, you know, several advantages
of using compost which we should take care. You know, take into consider consideration
and that is why nowadays in all the countries this application of compost is highly recommended
and it is also environmental friendly and for I would say for any integrated nutrient
management practices now a days, the application of compost is recommended along with the chemical
fertilizer for maintaining the environmental sustainability. So, let us talk about composting in India,
now generally composting can be carried out in 7 techniques in India and they are basically
listed here. One is Bangalore method and then another is
Indore method, then Nadep compost, then Nadep phospho compost, then Coimbatore method, then
windrow composting and vermicompost. Now in this lecture we will be covering only
Indore method, Nadep compost and vermicompost because these are important in India and also
Bangalore method and we know Coimbatore method is important. However, we will not have time to discuss
those in details, but if you are interested you can go ahead and search some literature
which will discuss in the those in details. So, let us start with the Indore method. So, but before that before discussing Indore
method in details, let us see who develop this methods. So, this Indore method was developed by A.
Howard and Y.D. Wad at the institute of plant industry that
is in Indore, India. So, that is why this method is known as Indore
method and Bangalore method was worked out by L.N Acharya at Indian institute of science,
Bangalore and Nadep method was, you know, first demonstrated by this, you know, at this
J.N. Krishi Vidyalaya at Indore. So, these are 3 important methods of composting
in India. Now, let us start with the Indore method. Now in case of Indore method the pits will
look like this. So, you have to create the pits and size of
the pits will be the breadth will be 6 to 8 feet depth will be 2 to 3 feet it should
not be more than 2 to 3 feet and length should be 10 feet or more as per the requirement. So, what are the raw materials we generally
use in case of Indore method? Mix plant residues generally use, we also
use cow dung, we also use weed, sugarcane we also use urine, soap, mud and grass and
wood ashes, bran etcetera. So, these are the materials which we use as
the raw materials in Indore method of composting. So, let us see how we can create this Indore
method of Indore compost. So, first of all we have to spread dry leaves
with cattle dung and in soil in the ratio of 4 is to 2 is to 1 up to 2 inch layer in
the composting pit. So, this is a first layer and pit is filled
with above material up to 1 foot above the ground level ok. Now after that once it reaches the one foot
above the ground level, then we have to sprinkle the water over the materials and 1 more layer
of bedding materials with wood ash and urinated mud should be added. So, this is how it is created layer by layer
and we can go up to 1 feet above the ground. So, after we place the compost for decomposition,
we need to give some turning, now turning is required for proper aeration and moisture. So, you can see the material for proper aeration
and moisture and we required at least 3 turnings. So, first turning is basically given at 10
to 15 days after filling the pits and second turning is given 15 days after first turning
and the third turning is given basically after 2 months of second turning. So, these turnings are necessary for proper
aeration and moisture and proper formation of compost, so this is about the Indore method
of composting. Now, let us talk about Nadep method, now this
method facilitates a lot of composting through minimum use of cattle dung and in this method
the decomposition process takes place aerobically and the tank should be located near the cattle
shed or farm site and important is the tank should be 10 feet by 6 feet by 3 feet in size
and are prepared within 9 feet in 9 inch thick wall. So it should be 9 inch thick wall. So, proper blocks and holes of 7 inch should
be left on all the 4 sides of the tank valve for the circulation of air. So, you can see this an example of Nadep compost
bed and you can see all the holes are created for proper aeration and circulation of air
and plastering of inner wall and floor. So, the tank should be done by mixing of dung
and mud so this is very very important. So, this is how we create a Nadep compost
pit and again remember this method was first demonstrated in J.N. KV in Indore. So, in case of Nadep methods these are the
materials which are required, first of all we require farm residues because it, you know,
in the previous slide you have seen that we should make this pit near the farm. So, farm residues will be used as an important
raw material for this Nadep compost. So, we require 1400 to 1500 kg of farm residue
we require cattle dung of 90 to 100 kg, we require dry sieved soil of 1750 kg and then
water in 1500 to 2000 litre. So, these are the raw materials which we require
for this Nadep compost. So, what are the filling process? So, there 2 at least 2 filling processes. So let us talk about the first filling process
in case of Nadep compost. So, first of all slurry made of cow dung and
water should be sprinkled on the floor and the walls of the tank and the filling of the
tanks follows this following steps. So, first layer obviously plant residues are
spread evenly in layer of 6 inches that is 10 to 100 kg in the tank and second layer
4 to 5 kg cattle dung of biogas slurry in 125 to 150 litres of water should apply on
the first layer and in the third layer 50 to 60 kg of sieved soil added on the second
layer of the tank. So, again in the first layer will be produce
will be will be will be applying plant residues and we will be spreading the plant residues
evenly in layer up to 6 inches and then in the second layer, we will add 4 to 5 kg of
cattle dung of biogas slurry in 125 to 150 litre of water and applied in the over the
first layer and in the third over that in the third layer, we will add 50 to 60 kg of
sieved soil in the over the second layer of the tank. So, in this way the tank is filled layer by
layer up to 1.5 feet over the above the brick level of the tank. Now this filled tank should be covered and
sealed by 3 inch layer of soil that is 300 to 400 kg and it should be pasted with a mixture
of dung and soil. So, if you go back and see the previous slide
where I have shown you, so this is the plastering you can see at the top with cow dung and soil
mixture which is required for this Nadep method. So, you spread all this required raw materials
in layers by layers and after that once it reaches a required depth after the over the
bricks of the tank, then you plaster it through the mixture of soil and this cow dung. So, this is basically the process of first
filling. Now, what is the process of second filling? At this stage, the process of the first filling
is repeated again and sealed with paste of mud and dung. So, after 20 days the plant residues contracts
and goes down in the tank by 20 to 25 inches, obviously because when the decomposition will
go on. Obviously, there will be reaction in the volume
and reduction in the weight and periodically the paste of cattle dung and water should
be sprinkled to maintain the 15 to 20 percent of the moisture. So, this is the method of second filling in
case of Nadep method. So, guys we have completed these 2 methods
important methods; obviously, the other methods are Bangalore method and Coimbatore method
you can you can consult some literature to search in details about those methods. But let us talk about very important process
that is vermicomposting. A vermicompost also called worm compost or
vermicast or worm casting or worm humus or worm manure. So, there are several names for this, we know,
compost is basically end product of the breakdown of organic matter by some species of earth
worm. Basically the epigeic earth worms. So vermicompost is a nutrient rich natural
fertilizer and soil conditioner. It improves the soil physical chemical and
biological conditions. So the process of producing vermi composting
is known as vermi I am sorry. So, the process of producing vermi compost
is known as vermicomposting. The earthworm species or composting worms
most often are, you know, brandling worm. So, also known as Eisenia foetida, it is a
most important worm or sometime red wigglers like Lumbricus rubellus and also Perionyx
excavates, Eudrilus eugenie. So, these are some common, you know, common
species of earth worm which we use for producing the vermi compost. So, now, you can see this is vermicompost
and how we produce the vermi compost we will see in the next slide. So, vermi culture which is derived from the
Latin word vermis meaning worm and it involves the mass production of earthworm for waste
degradation and composting with vermicast production. So, earthworms remember they are the intestines
of the earth. Vermi comes from the, you know, vermi means
worm and it involves this vermiculture means the mass production of earth worms for waste
degradation. So, they occur in diverse this earth worms
occur in diverse habitats especially those which are dark and moist areas and organic
material like humus, cattle dung and kitchen waste are highly attractive for some species. So, they ingest those materials some amount
they, you know, retain for their own biomass creation and they convert the other. you know, remaining portion and they just
excrete it out and that is a very very huge source of nutrient. So, this is called the vermicompost. Now, what actually these earth worms do, so
they basically maintain the aerobic condition in the mixture. So, basically they ingest soil and convert
a portion of the organics into the worm biomass and to respiration and to respiration products
and expel the remaining partially stabilized matter and discrete material we call it castings
and these are basically the worm cast or vermicompost. So, worms and aerobic mesosphilic microorganism
act symbiotically to accelerate and enhance the decomposition of the organic matter. So, that is how this is another form of worm
compost and this compost we shall add to different for encouraging the growth of the different
plants. So, what are the properties important properties
beneficial properties of the vermicompost, well they are very finally structured, uniform
stable and aggregated particles of humified organic material. And they have excellent porosity, aeration
and water holding capacity and they are rich in available plant nutrients and hormones,
enzymes and microbial populations. And they are mostly pathogen free because,
plant and human pathogens are killed during the passage of the earth worm gut and earth
like soil building substances that forms a building a beneficial growing environment
within the in the for plant roots and their these vermicompost are valuable and marketable
products. So, again these if we apply this vermicompost
into the soil, they improve the soil aggregation, they have excellent they increase the porosity,
they increase the aeration, increase the water holding capacity all these are beneficial
in nature. Also they are rich in plant nutrients which
helps in, we know, a proper growth of the plant, they secretes some hormones, they secrets
enzyme for degradation of organic matter or conversion on or the nutrient transformations,
they are pathogen free. Another good thing about this vermi compost
they are, you know, they are virtually odour free, so these are very good I mean they are
not producing any odour. So, plant and human pathogens are also killed
because, we know, they are moving through the guts of the earthworms and the you can
sell this products it is a very very valuable and marketable product because, these are
very very attractive things for gardening and the, you know, vegetable crops. So, this is the vermicompost pit, basically
vermicompost can be done, you know, vermicompost are developed in the shady area. So, basically we develop the pits you can
see here using different materials, you can see you can you can create these vermicompost,
we know you know, vermicompost pits using some mud, using bricks and within these vermicompost
pit, you can basically spread layers of different materials. Basically you can add farm residues or kitchen
wastes and then you can add a slurry of cow dung as well as water and after that, you
can further add another layer of these a farm residues and all these things and after that,
you know, after that these earth worms are released here in these vermi beds and we have
to create a uniform moisture condition and they are basically covered through some, you
know, moist bags to maintain the moisture condition. And after a certain period of time these microorganisms
will ingest this materials and ultimately they will convert these materials into vermi
compost which can be further sieved and, you know, further it, you know, once this material
will be produced they will be dark in colour, they will be odour free and basically they
will be harvested and then sieved pact in the as a final product. So, this is a vermi composting product guys. So, you can search some several materials
or literature which are we which talks about this vermi casting composting process. There are different processes of vermicomposting,
but obviously one thing is common. All of them are using different, you know,
all of them are using the, you know, earthworms for production of vermicompost and these vermicomposts
are very very beneficial for the growth of the plant. And so guys there are other also different
other types of compost like kitchen compost you can you can you can search some literature
about those thing and there are some available bio digesters which are now available which
you can use in your home to produce your, to produce the compost for your own kitchen
garden, because each and every day the kitchen waste which are generated we can recycle those
kitchen waste into the one, you know, in inside those bio digester to produce the organic
compost. So, the, you know, composting is a very very
interesting process and these composting process is very very environmental friendly guys and
these are also very very beneficial. So, it is a very important waste management
practices solid waste management practice. So, let us wrap up the week 8 lectures here
I hope that you have learnt something new in this week and we have covered several important
topics like soil testing, like, we know, organic matter, like macro and micro organism, then
composting, then vermicomposting all these are important topics I hope that you have
got some basic overview of these important topics. And if you are interested please feel free
to email me to learn in details or you can go ahead and search some literature to gain
further knowledge. Thank you very much and in the next lecture
we will be starting the week 9 of lectures. Thank you very much guys.

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