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Lake 2010: Wetlands, Biodiversity and Climate Change
22nd-24th December 2010 Page 1
COMPOSTING AND VERMICOMPOSTING, A SIMPLE WAY !
Dr. Rinku Verma
Faculty in Environmental Science Department, Bangalore University
Abstract
In any environment, recycling of the degradable waste is the natural way of replenishing it. Because of the
negligence and indifference, the damage to the environment has surpassed the replenishment. The
concentration of the toxic matter has increased which in turn has decreased the pace of the natural
degradation. Poisonous gases in the atmosphere, concentration of the chemicals in the soil and water etc
have accelerated the development of pathogenic mutants of organisms which by infecting human beings,
animals and crop contributed to the decline in the productivity. This is the major stumbling block in the
advancement of the nation. The methods to curb the environmental degradation and also improve the
environment are area specific, as the parameters are different at different areas. This paper highlights
simple methods used for composting and vemicomposting of organic waste. The usefulness of
vermicompost has also been indicated.
Introduction
Waste is a useful material in a wrong place. It is a reusable resource and national asset. It is a rich
source of food and energy if utilized properly. If not it is polluting, creates health and aesthetic problems.
We want India to be in the developed nation in the next few years. Importance hence must be given to
waste management and energy from the waste and manure making which is one of the steps towards
sustainable development.
Source –wise Generation of Solid Waste in Bangalore Stake holder Volume (tonnes/day) % Households 650 18 Commercial Establishments Markets Hotels
369 1066
39
Institutes 128 Hospitals Offices Educational institutes
20 15 92
Industries 1399 39 Total 3613 100 (Pieter et al, 1999)
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It becomes necessary to do composting at home, in the neighbourhood, parks, schools etc., as
already some areas are doing. Absence of a proper landfill site can be considered as the most important
short term issue in solid waste management in Bangalore. Fraction of compostable materials is collected by
the municipality and delivered to farmers near Bangalore city who use it to enrich their soil.
Efforts are being carried out in Bangalore by bringing NGOs, Schools, and Colleges to take part and have a
better waste management program.
According to earlier estimates, during the mid 90’s Bangalore generated approximately 2,000 tonnes of
solid waste per day, which was in the later years estimated to be around 2,500 tonnes per day. At present, it
is estimated that Bangalore generates about 3,613 tonnes of solid waste per day including industrial waste
as given in the above table.
The municipality collects about 1,139 tonnes of waste per day from the Public Dust Bins. Of this, about
200 tonnes are directly sent from the major markets to large composting units such as Karnataka
Composting Development Corporation (Govt concern) and several private composting units located in the
city. The remaining waste collected by the municipality is dumped in open spaces and on road sides outside
the city. In addition, about 245 tonnes of waste per day is dumped or burned by the generators themselves.
This may include debris burnt waste etc., (unorganized waste) which remain uncollected in the city.
From Bangalore we have the following percentage of waste 30-35% Biodegrade 20-35% Fine/street waste 20-35% Waste with moisture content 10-12 % Recyclable Including a lot of E – Waste, because Bangalore is an IT hub with many IT companies. It is estimated that by 2020 we would have 13 million tonnes of solid waste. And by 2030 this would go up
to 2000 million metric tones. It may go up to 48 million tonnes by 2047.
Managing solid waste, the composting way!! “Solid waste management at home” -The Domestic Way Biodegradable solid waste is the cause of a number of diseases due to water and air contamination.
If the biodegradable waste is converted into compost it not only reduces the pollution but also is profitable.
There is some awareness about the conversion of the waste into compost. But majority of the public is still
unaware of this. Otherwise, the cities like Bangalore, Mumbai etc., would not be stinking with the garbage
littered on the side walks, garbage bins and the municipalities with collection problems of disposing off the
waste. The problem is increasing in leaps and bounds.
Hence initiation of popularizing the solid waste management, organic farming, reclamation of the
degraded land and purification of the polluted water and air would be very useful in sustainable
developmental practices, with “Ecological research interest for alleviation of the environmental problems”.
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Fresh compost being collected after biodegradation
Pit filled with compost and the fresh waste above Solid waste at home is to a large extent biodegradable and a small quantity of it may be degradable or non
degradable. Biodegradable waste is a nuisance as it decays rapidly and produces obnoxious smell if not
disposed in the right way.
Biodegradation in the right way is very beneficial. Biodegradable waste is of plant and animal origin. It
may be kitchen or garden waste. This can be easily converted into compost and profitably used in growing
plants in your garden or in the pots.
Compost improves the quality of the soil and supplies nutrients to the plants
To prepare the compost (with reference to kitchen waste, garden waste can be used if the area is
larger)
1. Make at least two pits in the garden or get two drums of convenient size,
2. Throw the biodegradable waste into one of the pits or the drums,
3. Cover the waste by a layer of soil to prevent any smell from the waste escaping,
4. Sprinkle water to keep the soil and the waste wet,
5. Whenever waste is available throw it into the pit or the drum and cover by the mud, (option, if
composting is done in pits cover by mud layer can be once a week and just a thin layer)
6. Sprinkle water,
7. Repeat the process till the pit or the drum is full,
8. When the pit or the drum is full, sprinkle water at intervals of two or three days,
9. Repeat sprinkling of water for a month or more,
10. In the mean time use the other pit or the drum and repeat the procedure.
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11. Provide any option for a small hole at the bottom of drum. So that excess water can be removed.
12. Provide a covering if possible over the drum or pit.
In about a month/two after the pit or the drum is full it will have a healthy blackish powder of compost
without any offensive smell. Non-pathogenic microorganisms have done their job.
Take out the compost.
Sieve it to remove the undegraded material which may be few sticks or the other non degradable material
which have fallen into the pit by mistake.
Burn the undegraded organic matter (sticks etc) and mix the ash with the compost
This compost can be used during planting, by mixing it with the soil. The proportion of mixing the compost
with the soil depends on the type of the plant. The plants grown in the compost soil mixture are lush green
and are more productive. Flowers and fruits produced are better in taste and flavour. Consumable produce
is good for health.
Time taken for monitoring composting may be few minutes every day. But the returns are
significant. Apart from the returns, it is a service to the society. If every body takes up this, there will be no
stink and filth around. So as a good citizen it is our duty to do this and propagate the idea.
Procedure followed:
1. Spread the waste in the pot or the drum.
2. Watering should be only to wet the soil and the waste. If more water is poured there will be
water logging and quality of the compost will be spoilt.
3. Let the waste undergo complete degradation otherwise a stinking odour prevails (this is the
time when waste is sill in the process of biodegradation rather getting decomposed to form a
compost, this should not be applied to the plants as it is still not ready).
4. Family members, including children can get together to make a compost, it is so easy.
Normal Compost Making Method : The Commercial/ Institutional Way
1. Collection
2. Separating plastic, metallic items, thermocol,
3. Digging of the pits 6*4*4, can be longer. The pits can be lined by cement bricks. But the
bottom should be of clay bricks
4. Load the pits with vegetable matter cut into small pieces. Soft and tender parts are only loaded
into the pits. Woody parts can be burnt and the ash can be used. Load the vegetable matter to
a height of 2 ft.
5. Put a layer of dung
6. Cover the pits by mud which is sieved to remove stones to a depth of 2 to 3 inches
7. Water to drench the mud and wet the materials below
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8. The process is repeated by another layer so that the mound is a foot so above the ground level.
It is better to prepare all the layers at a time in few days the mound will subside to below the
ground level.
9. Watering should be done every alternate day, moderately so that there will not be any water
logging. There is no need of watering during the wet seasons. If available urine can be poured
into the pit. The soil layer at the top of the pit better be 4 inches thick. Cover the filled pits by
palm frounds.
10. Compost will be ready in a month or two. Addition of bone meal, meat meal, poultry
dropping et., improve the quality of the compost
Vermicomposting :
During the process of vermicomposting earthworms maintain aerobic conditions in the organic wastes by
proper mixing and microbial decomposition of the substrate in the intestine of earthworm, converting the
organic wastes into worm biomass and excretion of casts which are vermicompost (Benitez et al., 1999).
Preparation of Vermicompost expressed diagrammatically
Sprinkle water, Add every day 6cm thick organic waste, Water, Compost will be ready in 30-60 days (depends on the number of worms, climate etc.,), Remove, Sieve, Use worms again, (Clean up after every operation)
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Wire netting
Organic material
Earthworm
Fresh Farm Yard Manure
Coir (10cms)
Pebbles (10cms)
Stills
Worm wash
Points to be noted Neem powder is required to be added to the compost to avoid fly Cowdung is applied on the surface of the compost Aeration and Mixing is required (3 times), start only after 10th day Provide a mesh (net) above the surface at an elevated height Add culture of microbes into the mixture of compost & interfering chemicals This process is known as “bioaugmentation” to improve either efficiency or rate of abatement of organic pollution Possible degradation of a wider number of organic pollutants should be taken into account while composting carried out in mesophilic range Coconut husk acts as a mesh to cover the pits. This is to avoid files and other insect rodents.
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Types of vermicompost bins necessary for a better yield and multiplication of earthworms
Picture 1. Indicates bins/box made specifically for Vermicomposting (100 worms have to be put inside one such bin/box)
40 days vermicompost is ready
100 worms multiply to 400 worms
Cost of earthworms are Rs 450/- for 1000 earthworms
Layers of waste have to be put
The bins have pores below them and water easily drains away, without stagnation into the bins making it
suitable for earthworm activity
Using a shower can regularly keep this unit moist; preferably when the bin is filled a wet jute material is
put above and covered.
During vermicomposting one has to remember to separate the worms before the manure is added to the
plants and use earthworms which produce compost at a faster rate.
The disadvantage of this bin is the side plastic sheet has to be changed once or twice in a year and hence it
is recommended to just have this as a sample.
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Picture 2. Pits made above the surface of the ground (cement construction of pits, a view) The commercial way! The above pictures, 2 can be used for vermicomposting or composting purposes. Care should be taken to
avoid the ants as they may damage the worms.
Some Don'ts...
Don't put plastic bags, bottle caps, rubber bands, sponges, aluminum foil and glass in the bin. These
materials will be there forever and make your worm bin look like trash.
Don't let your cat use your worm bin as a litter box. First, cat urine would soon make the odor intolerable.
Secondly, the ammonia in the urine could kill your worms. There is also a concern with toxoplasmosis, a
disease that is of particular concern to a pregnant woman who may pass on the disease to her unborn child.
If you have cats, provide a screen or other device to keep them from using the worm bin as a litter box.
Don't use insecticides around your worm bin. You'll not only take care of a few pests, but also your
worms.
Don't use garden soil as bedding for the worms.
Don't mix fresh cow, horse and especially chicken manure into your bedding. These manures will heat up
the bedding and literally cook your worms (Mary Appelhof
http://lancaster.unl.edu/pest/resources/107Vermi.pdf).
Information related to earthworms and vermicast
Choice of the right species of earthworm for vermicomposting is foremost step of vermicomposting ( Aliva
Patnaik, http://dev4india.org/articles/vermitechnology.html). Earthworms (also called nightcrawlers) are
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very important animals that aerate the soil with their burrowing action and enrich the soil with their waste
products (called castings). Good soil can have as many as as 1,000,000 (a million) worms per acre.
Earthworms play an important role in soil ecology. By being continually loosened, stirred up, and aerated
by the action of earthworms, soil is made more fertile. Earthworms also form a source of food for many
animals, and constitute the principal food of moles and shrews.
Earthworms must live in moist soil containing organic matter. During unusually hot weather they also
penetrate downward to avoid dehydration. Earthworms shun daylight, but frequently come to the surface of
the soil at night to feed and to throw off their castings. In the daytime they appear upon the surface of the
soil only under unusual conditions, such as the flooding of their burrows by excessive rainfall.
In burrowing, they swallow large quantities of earth that often contain considerable amounts of vegetable
remains. They are able to digest the nutritive matter of the soil, depositing or casting out the remains on the
surface of the earth or in their burrows.
Diet: Earthworms eat soil and the organic material in it - like insect parts and bacteria.
Earthworms, as they burrow and feed, swallow the soil, digest it, extract its food value and expel the
residue as worm castings which are far richer in nitrogen, phosphate, calcium, and magnesium than the
finest of ordinary good top soil. Worms actually MAKE rich dirt. Not only do worms create this wonderful
soil for our gardens and yards, but composting also greatly reduces the amount of the garbage that is sent to
our dumps and landfills.
Worms love to eat all kinds of food. They love food scraps, (but not meat, bones, or dairy products
because these may cause unpleasant odors or invite unwanted ‘guests’ into your worm bin). They also eat
cardboard, and even material from vacuum cleaner bags. Then they turn it into nutrient-rich compost
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(castings). These castings can be used as a fertilizer for all types of plants. Worm castings are the richest
form of natural fertilizer known to man. This will promote higher than average growth in plants
Earthworm Life Cycle:
Earthworms are
amazingly prolific breeders. A thousand mature breeders, properly cared for and allowed to multiply, may
give you half a million or more breeders, growing earthworms, and egg capsules within a year. Earthworms
are bisexual, having both male and female reproductive organs. Each worm produces egg capsules, but
must first be fertilized by contact with another worm. Each healthy worm, under favorable conditions, will
produce an egg capsule every 7 to 10 days. These incubate in 14 to 21 days, each hatching 2 to 20 young
worms, with an estimated average of 4. The new worms thus hatched will reach breeding age in 60 to 90
days, as indicated by the formation of clitellum...a thick ring about 1/3 the length of the worm from its
head. The domesticated earthworm will continue to grow, after reaching the breeding stage, for perhaps six
months or more before reaching its full size (http://www.workingworms.com/index.html).
Earthworms for Soil Improvement:
The earthworm has been aptly called, "The Gardener's Unpaid Handyman." It tills the soil around root
areas by its tireless burrowing. The burrows form channels through which root growth may reach down into
the subsoil for minerals and moisture. They also absorb rainfall quickly for storage in the soil instead of
allowing it to run off, carrying away valuable top soil. Most important of all, the earthworm eats, digests,
and enriches dead and decaying vegetable wastes in the soil, ejecting it in the form of casts (as mentioned
earlier), rich in plant food value, water soluble, immediately available to plant roots.
For the success of your vermicomposting:
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It is important to note that do not feed earthworms; metals, foils, plastics, chemicals, oils, solvents,
insecticides, soaps, paint, etc. Avoid all citrus products (oranges, lemons, limes, grapefruit), onions, garlic
cloves, extremely hot and heavily spiced foods, and high acid foods. Also, avoid oleanders and other
poisonous plants meat, chicken, dairy foods, dog and cat manure (NIIR Board,2004).
Earthworms can be fed all forms of food waste, yard and garden waste, paper and cardboard, etc. Yard
wastes, such as leaves, grass clipping, straw, and non woody plant trimmings can be composted. Leaves,
are the dominant organic waste in most backyard compost plies. If grass clippings are used, it is advisable
to mix them with other yard wastes, otherwise the clippings may compact and restrict airflow. Branches
and twigs greater than ¼ inch in diameter should be put through a shredder/chipper. Kitchen wastes such as
vegetable scraps, coffee grounds, and eggshells may also be added. Sawdust may be added in moderate
amounts if additional nitrogen is applied. Approximately 1 kg of actual nitrogen is required for 100 kg of
dry sawdust. Wood ashes act as a lime source and if used should only be added in small amounts (5 kg per
ton of waste). Ordinary black and white newspaper can be composted; however, the nitrogen content is low
and will consequently slow down the rate of decomposition. If paper is composted, it should not be more
than 10% of the total weight of the material in the compost pile (NIIR Board 2004).
Animal dung
Cattle dung, sheep dung, horse dung, goat dung and poultry dropping etc may used for this purpose. In use
of animal dung other than cattle dung, various preliminary testing and precautions for pathogens and
responses to earthworms are necessary. The uses of horse dung should be done carefully because tetanus
virus is common in horse dung and is lethal to human beings.
Agricultural waste
Agricultural waste obtained after harvesting and threshing may be used. They include stem, leaves, husk
(excepting paddy husk), peels, vegetable waste, orchard leaf litter, processed food wastes, sugarcane rash
and baggase; and processing wastes.
Forestry wastes
These are plant products such as wood shavings, peels, saw dust and pulp. All these besides various types
of forest litter can be used. The unutilized forest waste such as leaf litter may also be used for
Vermicomposting.
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City leaf litter
The burnt leaf litter from avenue or residential areas may be used, however, reports are not available. If it is
used, this would keep cities clean and would provide useful product. The leaf litter of mango, guava,
grasses and certain weeds (free from seeds) may be used, but we need more information on this aspect.
Waste paper and cotton cloth etc.
These are decomposable organic waste. These if are not being recycled for other useful products, can be
recycled with Vermicomposting.
City refuse
City refuse or garbage on daily production basis comprise important items of city factors and a
considerable portion of city refuse can be sorted and recycled or composted. Most of household as kitchen
waste with little manipulation can be used for vermicompose.
Biogas slurry
After recovery of biogas, if not required for agricultural use, viz., in conventional composting can be used
for Vermicompositing.
Industrial wastes
The industrial wastes like waste from food processing, distillery etc. can also be used in vermiculture with
some manipulations.
Vermicast
Vermicast is produced by the feeding action of earthworms. Earthworms ingest organic matter, fragmenting
and grinding it into a finely divided peat like material with high porosity, aeration, drainage and water
holding capacity. This process enhances microbial activity and accelerates the rate of decomposition. This
leads to a humification effect where unstable organic matter or decomposing plant and animal matter is
oxidized and stabilized. Micro organisms present in vermicompost inactivate and suppress the growth of
pathogens (Kale, 1998; Shobha, 2005).
Humus forms the dark brown or black mass of the upper soil and is important for storing and releasing
plant nutrients. The process is similar to composting except it is non thermophilic or a cold process utilising
naturally occurring soil dwelling microorganisms. Vermicast has a large surface area and a high cation
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exchange capacity providing strong absorbability and retention of nutrients (Atiyeh et al, 2001).
As a fertiliser, vermicast contains nutrients in a form that are readily taken up by plants, such as nitrates,
exchangeable phosphorous, soluble potassium, calcium and magnesium (Edwards & Burrows, 1998)
A typical breakdown of vermicast is as follows:
pH N P K S Mg Ca CEC (Me/100g) Organic Matter (humus)
6.6 2.3 3.0 0.6 0.1 0.65 8.6 52.75 20%
Comparison between Vermicast V/s. Chemical Fertilizers
Criteria for Comparison
Chemical Fertilizers Vermicast
Macro nutrient contents
Mostly contains only one (N in urea) or at the most two (N & P in DAP) nutrients in any one type of chemical fertilizer
Contains all i.e. nitrogen (N), phosphorus (P) & potassium (K) in sufficient quantities
Secondary nutrient contents
Not available Calcium (Ca), magnesium (Mg) & sulphur (S) is available in required quantities
Micro nutrient contents
Not available Zinc (Zn), boron (B), manganese ( Min), iron (Fe), copper (Cu), molybdenum (Mo) and chlorine (CI) also present
pH balancing Disturb soil pH to create salinity and alkalinity conditions
Helps in the control of soil pH and checks the salinity and alkalinity in soil
EC correction Creates imbalance in soil EC Affecting nutrients assimilation
Helps in balancing the EC to improve plant nutrient adsorption
Organic carbon Not available Very high organic carbon and humus contents improves soil characteristics
Moisture retention capacity
Reduces moisture retention Capacity of the soil
Increases moistures retention capacity of the soil
Soil Texture Damages soil texture to reduce aeration
Improves soil texture for better aeration
Beneficial bacteria fungi
Reduces biological activities and Thus the fertility is impaired
Very high biological life improves the soil fertility and productivity on sustainable basis
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Plant growth hormones
Not available Sufficient quantity helps in better growth and production
http://www.morarkango.com/biotechnology/research.php
References: Aliva Patnaik http://dev4india.org/articles/vermitechnology.html Atiyeh, R.M., Arancon, N., Edwards, C.A., Metzger, J.D., 2001. The influence of earthworm processed pig manure on the growth and productivity of marigolds. Bioresource and Technology 81, 103-108., Benitez, E., Nogales, R., Elviva, C., Masciandara, G. and Ceccanti, B. 1999. Enzymatic activities as indicators of the stabilization of sewage sludges composting with Eisenia foetida, Bioresource Technology 67: 297-303. Edwards, C.A., 1998. The use of earthworms in the breakdown and management of organic wastes. In: Edwards, C.A. (Ed.), Earth-worm Ecology. CRC Press, Boca Raton, FL, pp. 327±354 Kale, R.D. 1988. Earthworm; Cinderella of organic farming. Publ. Prism Books Pvt. India pp. 88. Mary Appelhof, Worms eat my garbage, Published by Flower Press10332, Shaver Road, Kalamazoo Michigan 49002 http://lancaster.unl.edu/pest/resources/107Vermi.pdf
Morarka Foundation http://www.morarkango.com/biotechnology/research.php
National Institute of Industrial Research Board 2004, The complete technology book on Vermiculture and Vermicompost. Published by NIIR, pages 354 http://niir.org/books/book/complete-technology-book-on-vermiculture-vermicompost-niir-board/isbn-8186623817/zb,,74,a,5,0,3e8/index.html
Pieter von Beukering, Madhushree Sehker, Reyer Gerlagh and Vijay Kumar, 1999. Analysing Urban Solid Waste in Developing Countries: a Perspective on Bangalore, India, Working Paper No 24, Institute for Social and Economic Change Bangalore 72
Shobha, S.V. 2005. Influence of earthworm extracts on some plant pathogens. M.Phil. Dissertation submitted to Bharathidasan University, TN, India pp.51.