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COMPOSTING OF ORGANIC WASTESComposting is a process of allowing organic materials to decompose more or less controlled conditions to produce stabilized product that can be used as a manure or soil amendment. Composting is basically a microbial process, which change the property of the organic material or mixtures.
Compost is the material resulting from the decomposition of plant residues under the action of bacteria and fungi. Composting is simply an acceleration of natural process or organic matter mineralization. The final product is dark brown in colour and resembles FYM in its properties and appearance.
Essential requirements for composting
- A bulky organic manure
- A suitable starter
- Addition of enough water
- Aeration
- ADCO process (Hutchinson and Richards of England)
- Activated compost process (Fowler and Rege)
- The Indore process (Howard and Wad)
- The Bangalore process (C.N.Acharya)
- The coimbatore method
∗ Enables clean environment
∗ Absorbs odors, degrade toxic substances and heavy metals
∗ Avoids un-necessary dumping of wastes
∗ Supply valuable organic manure
Composting technologies
1. Crop residue composting
Collect the available crop residues and weeds
Shred them to a size of 2 to 2.5 cm length
Mix these wastes with green residues (freshly collected), if available
Form the compost heap ( 4 feet height)
Add the bio-inoculants (2 kg of bio-mineralizer or 40 kg of cowdung for 1 tonne of waste)
Properly aerate the compost either by providing perforated PVC pipes or by mechanical turning
Maintain the moisture at 60 % by regular watering
The compost will mature in 60 days
2. Vermi-composting
Vermicomposting is a process of degradation of organic wastes by earthworms. The species like Eisenia foetida and Eudrilus eugeniae are effective in converting the agricultural wastes into compost.
1. Crop residue composting
Collect the available crop residues and weeds
Shred them to a size of 2 to 2.5 cm length
Mix these wastes with green residues (freshly collected), if available
Form the compost heap ( 4 feet height)
Add the bio-inoculants (2 kg of bio-mineralizer or 40 kg of cowdung for 1 tonne of waste)
Properly aerate the compost either by providing perforated PVC pipes or by mechanical turning
Maintain the moisture at 60 % by regular watering
The compost will mature in 60 days
2. Vermi-composting
Vermicomposting is a process of degradation of organic wastes by earthworms. The species like Eisenia foetida and Eudrilus eugeniae are effective in converting the agricultural wastes into compost.
The various steps involved in making vermicompost are as follows
Methods followed:
Heap method
Pit method – aboveground and belowground
Belowground method pit size : 10 X 1 X 0.3 m
Each layer : 6-7cm thick
Sprinkle water once in 8-10 days
Release : 2-2.5 kg worms / pit
Steps:
The nutrients content in vermicompost vary depending on the waste materials that is being used for compost preparation. If the waste materials are heterogeneous one, there will be wide range of nutrients available in the compost. If the waste materials are homogenous one, there will be only certain nutrients are available. The common available nutrients in vermicompost is as follows
Organic carbon = 9.5 – 17.98%
Nitrogen = 0.5 – 1.50%
Phosphorous = 0.1 – 0.30%
Potassium = 0.15 – 0.56%
Sodium = 0.06 – 0.30%
Calcium and Magnesium = 22.67 to 47.60 meq/100g
Copper = 2 – 9.50 mg kg-1
Iron = 2 – 9.30 mg kg-1
Zinc = 5.70 – 11.50 mg kg-1
Sulphur = 128 – 548 mg kg-
3. Coirpith composting
Coirpith is an agricultural waste produced from the coir industry. Approximately 180 grams of coirpith is obtained from the husk of one coconut. Coirpith contains Carbon : Nitrogen in the ratio of 112:1 and contains 75 per cent lignin which does not permit natural composting as in other agricultural wastes.
Mushroom Pleurotus has the capacity to degrade part of the lignin present in coirpith by production of enzymes like cellulases and lactases. The carbon: nitrogen ratio of coirpith is reduced from 112:1 to 24:1 as a result of composting.
Composting method
Select a shaded place of 5 x 3 m dimension and level it after removing weeds. Spread 100 kg of coirpith uniformly. Spread 100 g of Pleurotus spawn on this and cover with a second layer of 100 kg of coirpith. On the surface of the second layer, spread one kg of urea uniformly. Repeat this sandwiching of one layer of coirpith with spawn followed by another layer of coirpith with urea up to one metre height. Sprinkle water to keep the heap moist. Allow the heap to decompose for one month.
Manure conversion
The coirpith is converted into good manure after 30 to 40 days and the lignin content is reduced from 40 per cent to 30 per cent. The nitrogen content is increased from 0.20 per cent to 1.06 per cent. Coirpith compost contains macronutrients and micronutrients. It can absorb water up to eight times its weight. Coirpith, when added to sandy soil at 2 per cent increases the water holding capacity up to 40 per cent. It can be applied to a wide variety of crops and can be used to prepare potting mixture and can be applied as organic manure in kitchen gardens.
4. Composting of crop residues and weeds:
Composting is one of the useful ways for utilizing the some of the weeds and noncommercial plants like Parthenium, Water hyacinth, lpomoea etc. instead of their eradication. The plants can be composted using Trichoderma viridi and Pleurotus sajor- caju as a microbial consortium with supplementation of urea. Select an elevated shady area of a thatched shed and mark an area of 5x1.5 meter. Cut the composting materials into 10 – 15 cm size. Spread 100 kg of these materials over the marked area. Sprinkle 1 bottle of microbial consortia over this layer. Again spread another 100 kg of composting materials over this layer. Spread 1 kg of urea uniformly over this layer. Likewise repeat these processes of spreading composting materials, then microbial consortia, again composting materials followed by urea application until a minimum of 1-meter height is reached. Sprinkle water to attain a moisture level of 50% to 60%. The surface of the heap is covered with a thin layer of soil. Water should be sprinkled depending upon the necessity to maintain the moisture around 50%. A turning is given at the end 20 days to give a thorough mixing of outside material with that of the inside ones. The bio-converted compost will be ready in about 40 days time.
5. Method of composting the Municipal Solid Wastes
Biodegradable municipal solid waste should be separated and collected for composting. Five hundred kg of material should be heaped in the compost yard. In that heaped waste, 1 kg of TNAU microbial consortium should be applied in the form of slurry to cover the full waste material. This 1 kg microbial consortium can be mixed with 5 litres of water to make slurry. This slurry is sufficient to cover 0.5 tonne of material Then, 50 kg of cowdung should be mixed with 30 litre of water to form cowdung slurry. This cow dung slurry should be sprayed over the heap of municipal solid waste Then, 1 kg of urea should be mixed with solid waste. 60% moisture should be maintained through out the period of composting. Compost should be turned up once in 15 days to create good aeration, and for thorough mixing. Because of this practice, a uniform composted material will be obtained. Solid waste can be composted with in 90 days by this method with the indication of reduction in the volume, appearance of dark coloured materials and a small of earthy odour After the completion of composting, compost should be sieved through normal mesh to separate unwanted and partially composted material.
Methods followed:
Heap method
Pit method – aboveground and belowground
Belowground method pit size : 10 X 1 X 0.3 m
Each layer : 6-7cm thick
Sprinkle water once in 8-10 days
Release : 2-2.5 kg worms / pit
Steps:
- Collect the predigested wastes and mix cattle dung @ 30 %.
- Place it in the pit/container layer by layer
- Moist the residues at 60 % moisture
- Allow the verms in to the feed material / residues @ 1 kg/ tonne of residue
- Protect the pit or container from ants and rats (which are the enemies of verms)
- The residue will be composted in 30 to 40 days
- Remove the composted materials layer by layer at a weekly interval so as
- To avoid any damage /disturbance to the feeding verms.
The nutrients content in vermicompost vary depending on the waste materials that is being used for compost preparation. If the waste materials are heterogeneous one, there will be wide range of nutrients available in the compost. If the waste materials are homogenous one, there will be only certain nutrients are available. The common available nutrients in vermicompost is as follows
Organic carbon = 9.5 – 17.98%
Nitrogen = 0.5 – 1.50%
Phosphorous = 0.1 – 0.30%
Potassium = 0.15 – 0.56%
Sodium = 0.06 – 0.30%
Calcium and Magnesium = 22.67 to 47.60 meq/100g
Copper = 2 – 9.50 mg kg-1
Iron = 2 – 9.30 mg kg-1
Zinc = 5.70 – 11.50 mg kg-1
Sulphur = 128 – 548 mg kg-
3. Coirpith composting
Coirpith is an agricultural waste produced from the coir industry. Approximately 180 grams of coirpith is obtained from the husk of one coconut. Coirpith contains Carbon : Nitrogen in the ratio of 112:1 and contains 75 per cent lignin which does not permit natural composting as in other agricultural wastes.
Mushroom Pleurotus has the capacity to degrade part of the lignin present in coirpith by production of enzymes like cellulases and lactases. The carbon: nitrogen ratio of coirpith is reduced from 112:1 to 24:1 as a result of composting.
Composting method
Select a shaded place of 5 x 3 m dimension and level it after removing weeds. Spread 100 kg of coirpith uniformly. Spread 100 g of Pleurotus spawn on this and cover with a second layer of 100 kg of coirpith. On the surface of the second layer, spread one kg of urea uniformly. Repeat this sandwiching of one layer of coirpith with spawn followed by another layer of coirpith with urea up to one metre height. Sprinkle water to keep the heap moist. Allow the heap to decompose for one month.
Manure conversion
The coirpith is converted into good manure after 30 to 40 days and the lignin content is reduced from 40 per cent to 30 per cent. The nitrogen content is increased from 0.20 per cent to 1.06 per cent. Coirpith compost contains macronutrients and micronutrients. It can absorb water up to eight times its weight. Coirpith, when added to sandy soil at 2 per cent increases the water holding capacity up to 40 per cent. It can be applied to a wide variety of crops and can be used to prepare potting mixture and can be applied as organic manure in kitchen gardens.
4. Composting of crop residues and weeds:
Composting is one of the useful ways for utilizing the some of the weeds and noncommercial plants like Parthenium, Water hyacinth, lpomoea etc. instead of their eradication. The plants can be composted using Trichoderma viridi and Pleurotus sajor- caju as a microbial consortium with supplementation of urea. Select an elevated shady area of a thatched shed and mark an area of 5x1.5 meter. Cut the composting materials into 10 – 15 cm size. Spread 100 kg of these materials over the marked area. Sprinkle 1 bottle of microbial consortia over this layer. Again spread another 100 kg of composting materials over this layer. Spread 1 kg of urea uniformly over this layer. Likewise repeat these processes of spreading composting materials, then microbial consortia, again composting materials followed by urea application until a minimum of 1-meter height is reached. Sprinkle water to attain a moisture level of 50% to 60%. The surface of the heap is covered with a thin layer of soil. Water should be sprinkled depending upon the necessity to maintain the moisture around 50%. A turning is given at the end 20 days to give a thorough mixing of outside material with that of the inside ones. The bio-converted compost will be ready in about 40 days time.
5. Method of composting the Municipal Solid Wastes
Biodegradable municipal solid waste should be separated and collected for composting. Five hundred kg of material should be heaped in the compost yard. In that heaped waste, 1 kg of TNAU microbial consortium should be applied in the form of slurry to cover the full waste material. This 1 kg microbial consortium can be mixed with 5 litres of water to make slurry. This slurry is sufficient to cover 0.5 tonne of material Then, 50 kg of cowdung should be mixed with 30 litre of water to form cowdung slurry. This cow dung slurry should be sprayed over the heap of municipal solid waste Then, 1 kg of urea should be mixed with solid waste. 60% moisture should be maintained through out the period of composting. Compost should be turned up once in 15 days to create good aeration, and for thorough mixing. Because of this practice, a uniform composted material will be obtained. Solid waste can be composted with in 90 days by this method with the indication of reduction in the volume, appearance of dark coloured materials and a small of earthy odour After the completion of composting, compost should be sieved through normal mesh to separate unwanted and partially composted material.