Vermicomposting: A key for Solid Waste Management
Author: Samir Kumar Sahu
EXECUTIVE DIRECTOR,
MAYURBHANJ BIOLOGICAL RESEARCH (MBR),
EXECUTIVE DIRECTOR,
MAYURBHANJ BIOLOGICAL RESEARCH (MBR),
Introduction:
Solid wastes generated from agricultural activities include crop residues, animal excreta etc. which need special attention for disposal. The use of these wastes after bioprocessing can supply nutrients to vegetative plants and also improve soil physical chemical & biological conditions and its fertility (Bansal & Kapoor, 2000). The wastes can be either directly added to the soil (Lerch et al., 1992) or sometimes are to be treated before its addition to soil. This is due to presence of toxic pollutants or pathogenic microorganisms ( Ayuso et al., 1996; Hassen et al., 2001).
Review on solid waste management suggest that the wastes should be biocomposted before its use as nutrient source so as to attain the desired biological transformation of the organic matter and also to avoid risks of the pathogens.Among the various biocomposing measures, the vermicomposting has been considered to be an advantageous treatment system for different wastes (Logsdon, 1994; Ndegwa et al., 2000).
Another aspect of use of earthworms for vermicomposting of solid waste and use of vermincompost as source of rich nutrients is the realization of ill effects of the use of inorganic fertilizers during Green Revolution in early parts of 20th century. It has been established that maintenance of ecological balance for sustainable agriculture an alternative to chemical agriculture is use of vermicompost.
1.Role of earthworms & vermicompost:
Earthworms as a major soil fauna help in modulating the physicochemical properties of the soil.
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, converts the organic wastes into worm biomass and excretion of casts which are vermicompost (Benitez et al., 1999). The earthworms also enhance the soil microbial activity by improving the environment for the microbes (Syers et al., 1979).
Earthworm castings are a rich source of nutrients. The total nitrogen, organic matter, phosphorus, potassium, sodium and magnesium are higher in casts as compared to the surrounding soil. Earthworms are the major soil invertebrates which contribute to recycling of organic matter. Organic wastes are broken down rapidly after they are subjected to enzymatic activity in their gut. Primary decomposers (microbes) initiate the decomposition and secondary decomposers like earthworms further catalyze the process. The further fragmentation of organic residues increases the surface area enhancing the decomposition process by micro flora. During the process of respiration CO2 is released and production of mucus and nitrogenous wastes decreases the C/N ratio of organic matter by the earthworms.
Some of the epigeic (surface dwelling) earthworms are maintained as cultures to convert the organic wastes into their casts, the vermicompost. The vermicompost collected are used as source of organic fertilizers to be amended to the soil. In well irrigated fields, the earthworms are released along with organic wastes which help in enhancing earthworm activity in the field.
Now-a-days extensive research is in progress on earthworms and their role in organic nutrient waste conversion to produce nutrient rich vermicompost. By this process organic decomposable material derived from agriculture, animal husbandry and agro-industries can be converted to a rich source of bioresource. The earthworms can be utilized as ‘decomposer industry’ to take care of the organic wastes and make use of it as environmental resource instead of creating pollution (Macfadyen, 1963). Vermicomposting is helping the farming community to improve the status of the soil and also make additional income by selling vermicompost.
2.Vermiculture for vermicompost:
Biomass production of earthworms in semi natural conditions by providing suitable feed and conditions for them so that they remain active throughout their life is known as vermiculture. Vermiculture was associated to disposal of large amount of organic waste by Hertenstein, 1981. In 1981 Prince et al., utilized vermiculture for treating municipal wastes.
Number of earthworms are utilized for vermicomposting- they are mostly epigeic earthworms. Eisenia fetida is the most commonly used earthworm for vermicomposting due to its wide range of temperature tolerance, high reproductive potential and its less sensitivity to density pressure (Wanatabe and Tsukamoto, 1976; Reinecke and Kriel, 1981). Eudrilus eugeniae commonly called ‘African night crawler’ is another efficient earthworm for vermicomposting. It is found to be an efficient species for maintenance in India (Kale, 1994). Perionyx excavatus is also helpful in vermiculture. Kale (1994) has opined that mixed culture of Eudrilus eugeniae, Eisenia fetida, Perionyx excavatus, Perionyx sansibaricus can be successfully used for waste management in India.
In USA and Canada the vermiculture and vermicomposting has already been started as entrepreneurship where as in India it is still at research level. But since last decade, farmers, agro based industries and urban households are opting for culturing earthworms for managing organic waste management in India (Kale, 2002).
3.Process of vermicomposting:
Choice of the right species of earthworm for vermicomposting is foremost step of vermicomposting. And for this a suitable epigeic, widely distributed earthworm has to be chosen. Besides this the treatment of material to be used for vermicompost has to undergo certain procedures. In tropical countries optimal temperature of organic waste must range from 250 to 300 and moisture level from 40 – 60 % (Tripathy and Bhardwaj, 2004; Manivannan et al., 2004). Optimal moisture and temperature condition induces the micro organisms and the earthworms to act symbiotically to accelerate and enhance decomposition.
For vermiculture any type of organic residues like weeds, litter, hey, animal excreta available can be used. The collected residues are maintained at 40 - 60 % moisture for two to three weeks. After this the residues can be used for epigeic earthworm feed.
Vermicomposting should be practiced in shelter to prevent predators of earthworms like rodents. The vermicomposting tanks can be built with cement blocks, granite slabs or bamboo poles. The size of the tank depends on availability of raw materials. The breadth and the height should be preferably 1.2 and 0.9 mts. Temporary thatched roof protects the tanks from heavy sunshine or rainy season.
The feed (organic residue) is taken in the tank and earthworms are released on the surface. When the earthworms start feeding, the castings are released on the surface. These castings can be collected periodically.
Vermicompost i.e., collected castings from vermiculture bed contain small cocoons and earthworms. These can be separated by very simple method. Small balls of cow dung can be buried in collected vermicompost randomly. The earthworms hatched out of cocoons and other earthworms get attached to these cow dung balls and get separated from others.
Thus earthworms can be used as biological tools at industrial level to get vermicompost out of organics solid waste. By proper management of various factors like pH, temperature, moisture, texture of material and the quality of organic waste we can successfully convert the organic waste into very useful vermicompost (Parthasarathi, 2007).
4.Role of vermicompost in sustainable agriculture::
In tropical countries due to high temperature and low moisture, the use of inorganic fertilizers is not economical as there is only two fold increase in yield on application of ten fold increased use of inorganic fertilizers .
The organic carbon content is very low in tropical soil which is very important for soil organisms who contribute towards soil physical properties like aggregate stability, porosity, bulk density and water holding capacity. They also contribute towards immobilization as well as solubilization and mobilization of nutrients as and when required.
Thus vermicompost which can be prepared without large scale investment can be utilized as an organic amendment to enhance biological process in soil. Thus primarily vermicompost can act as medicine for the health of soil and secondarily as a nutrient supplier to the crop.
5.Physico-chemical parameters of vermicompost:
The nutrient content of the vermicompost depends upon the quality of the organic waste which is fed to earthworm. Still the vermicompost produced in proper manner has certain physico-chemical and biological characters as shown in the following table (Kale, 2002).
Physico-chemical parameters of Vermicompost
6.Advantage of vermicompost over other organic manures:
The available nutrients are more in vermicompost as compared to regular farmyard manure or compost. Moreover, secretions of earthworms present in vermicompost serve as growth stimulatory factors for plants (Galli et al., 1990) Shi-Wei and Fu Zhen (1991) have reported improvement in uptake of added inorganic nutrients in presence of vermicompost. Micro organisms present in vermicompost inactivate and suppress the growth of pathogens (Kale, 1998; Shobha, 2005). Yield of barley crop in pot cultures has been associated to higher levels of vitamin B12 in medium due to activity of inoculated earthworms (Atlavinyle and Daciulyle, 1969).
Further modification in the organic waste to be converted to vermicompost also influences the microfloral population in the vermicompost. Addition of 2 % neem cake to decomposing organic waste results in higher level of nitrogen-fixer population in vermicompost (Kale et al., 1986). Addition of 10 % rock phosphate to organic waste containing 10 % cow dung results in increase in phosphate solubilizing micro organisms.
7.Conclusion:
Vermicompost is best out of organic waste. On proper handing of the organic waste i.e., proper maintenance of certain physical and chemical properties of the organic waste, it can be converted into vermicompost, which will act as a conditioner for the soil health as well as a rich nutrient source for the crops.
Author contact address : -
SAMIR KUMAR SAHU,
Solid wastes generated from agricultural activities include crop residues, animal excreta etc. which need special attention for disposal. The use of these wastes after bioprocessing can supply nutrients to vegetative plants and also improve soil physical chemical & biological conditions and its fertility (Bansal & Kapoor, 2000). The wastes can be either directly added to the soil (Lerch et al., 1992) or sometimes are to be treated before its addition to soil. This is due to presence of toxic pollutants or pathogenic microorganisms ( Ayuso et al., 1996; Hassen et al., 2001).
Review on solid waste management suggest that the wastes should be biocomposted before its use as nutrient source so as to attain the desired biological transformation of the organic matter and also to avoid risks of the pathogens.Among the various biocomposing measures, the vermicomposting has been considered to be an advantageous treatment system for different wastes (Logsdon, 1994; Ndegwa et al., 2000).
Another aspect of use of earthworms for vermicomposting of solid waste and use of vermincompost as source of rich nutrients is the realization of ill effects of the use of inorganic fertilizers during Green Revolution in early parts of 20th century. It has been established that maintenance of ecological balance for sustainable agriculture an alternative to chemical agriculture is use of vermicompost.
1.Role of earthworms & vermicompost:
Earthworms as a major soil fauna help in modulating the physicochemical properties of the soil.
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, converts the organic wastes into worm biomass and excretion of casts which are vermicompost (Benitez et al., 1999). The earthworms also enhance the soil microbial activity by improving the environment for the microbes (Syers et al., 1979).
Earthworm castings are a rich source of nutrients. The total nitrogen, organic matter, phosphorus, potassium, sodium and magnesium are higher in casts as compared to the surrounding soil. Earthworms are the major soil invertebrates which contribute to recycling of organic matter. Organic wastes are broken down rapidly after they are subjected to enzymatic activity in their gut. Primary decomposers (microbes) initiate the decomposition and secondary decomposers like earthworms further catalyze the process. The further fragmentation of organic residues increases the surface area enhancing the decomposition process by micro flora. During the process of respiration CO2 is released and production of mucus and nitrogenous wastes decreases the C/N ratio of organic matter by the earthworms.
Some of the epigeic (surface dwelling) earthworms are maintained as cultures to convert the organic wastes into their casts, the vermicompost. The vermicompost collected are used as source of organic fertilizers to be amended to the soil. In well irrigated fields, the earthworms are released along with organic wastes which help in enhancing earthworm activity in the field.
Now-a-days extensive research is in progress on earthworms and their role in organic nutrient waste conversion to produce nutrient rich vermicompost. By this process organic decomposable material derived from agriculture, animal husbandry and agro-industries can be converted to a rich source of bioresource. The earthworms can be utilized as ‘decomposer industry’ to take care of the organic wastes and make use of it as environmental resource instead of creating pollution (Macfadyen, 1963). Vermicomposting is helping the farming community to improve the status of the soil and also make additional income by selling vermicompost.
2.Vermiculture for vermicompost:
Biomass production of earthworms in semi natural conditions by providing suitable feed and conditions for them so that they remain active throughout their life is known as vermiculture. Vermiculture was associated to disposal of large amount of organic waste by Hertenstein, 1981. In 1981 Prince et al., utilized vermiculture for treating municipal wastes.
Number of earthworms are utilized for vermicomposting- they are mostly epigeic earthworms. Eisenia fetida is the most commonly used earthworm for vermicomposting due to its wide range of temperature tolerance, high reproductive potential and its less sensitivity to density pressure (Wanatabe and Tsukamoto, 1976; Reinecke and Kriel, 1981). Eudrilus eugeniae commonly called ‘African night crawler’ is another efficient earthworm for vermicomposting. It is found to be an efficient species for maintenance in India (Kale, 1994). Perionyx excavatus is also helpful in vermiculture. Kale (1994) has opined that mixed culture of Eudrilus eugeniae, Eisenia fetida, Perionyx excavatus, Perionyx sansibaricus can be successfully used for waste management in India.
In USA and Canada the vermiculture and vermicomposting has already been started as entrepreneurship where as in India it is still at research level. But since last decade, farmers, agro based industries and urban households are opting for culturing earthworms for managing organic waste management in India (Kale, 2002).
3.Process of vermicomposting:
Choice of the right species of earthworm for vermicomposting is foremost step of vermicomposting. And for this a suitable epigeic, widely distributed earthworm has to be chosen. Besides this the treatment of material to be used for vermicompost has to undergo certain procedures. In tropical countries optimal temperature of organic waste must range from 250 to 300 and moisture level from 40 – 60 % (Tripathy and Bhardwaj, 2004; Manivannan et al., 2004). Optimal moisture and temperature condition induces the micro organisms and the earthworms to act symbiotically to accelerate and enhance decomposition.
For vermiculture any type of organic residues like weeds, litter, hey, animal excreta available can be used. The collected residues are maintained at 40 - 60 % moisture for two to three weeks. After this the residues can be used for epigeic earthworm feed.
Vermicomposting should be practiced in shelter to prevent predators of earthworms like rodents. The vermicomposting tanks can be built with cement blocks, granite slabs or bamboo poles. The size of the tank depends on availability of raw materials. The breadth and the height should be preferably 1.2 and 0.9 mts. Temporary thatched roof protects the tanks from heavy sunshine or rainy season.
The feed (organic residue) is taken in the tank and earthworms are released on the surface. When the earthworms start feeding, the castings are released on the surface. These castings can be collected periodically.
Vermicompost i.e., collected castings from vermiculture bed contain small cocoons and earthworms. These can be separated by very simple method. Small balls of cow dung can be buried in collected vermicompost randomly. The earthworms hatched out of cocoons and other earthworms get attached to these cow dung balls and get separated from others.
Thus earthworms can be used as biological tools at industrial level to get vermicompost out of organics solid waste. By proper management of various factors like pH, temperature, moisture, texture of material and the quality of organic waste we can successfully convert the organic waste into very useful vermicompost (Parthasarathi, 2007).
4.Role of vermicompost in sustainable agriculture::
In tropical countries due to high temperature and low moisture, the use of inorganic fertilizers is not economical as there is only two fold increase in yield on application of ten fold increased use of inorganic fertilizers .
The organic carbon content is very low in tropical soil which is very important for soil organisms who contribute towards soil physical properties like aggregate stability, porosity, bulk density and water holding capacity. They also contribute towards immobilization as well as solubilization and mobilization of nutrients as and when required.
Thus vermicompost which can be prepared without large scale investment can be utilized as an organic amendment to enhance biological process in soil. Thus primarily vermicompost can act as medicine for the health of soil and secondarily as a nutrient supplier to the crop.
5.Physico-chemical parameters of vermicompost:
The nutrient content of the vermicompost depends upon the quality of the organic waste which is fed to earthworm. Still the vermicompost produced in proper manner has certain physico-chemical and biological characters as shown in the following table (Kale, 2002).
Physico-chemical parameters of Vermicompost
6.Advantage of vermicompost over other organic manures:The available nutrients are more in vermicompost as compared to regular farmyard manure or compost. Moreover, secretions of earthworms present in vermicompost serve as growth stimulatory factors for plants (Galli et al., 1990) Shi-Wei and Fu Zhen (1991) have reported improvement in uptake of added inorganic nutrients in presence of vermicompost. Micro organisms present in vermicompost inactivate and suppress the growth of pathogens (Kale, 1998; Shobha, 2005). Yield of barley crop in pot cultures has been associated to higher levels of vitamin B12 in medium due to activity of inoculated earthworms (Atlavinyle and Daciulyle, 1969).
Further modification in the organic waste to be converted to vermicompost also influences the microfloral population in the vermicompost. Addition of 2 % neem cake to decomposing organic waste results in higher level of nitrogen-fixer population in vermicompost (Kale et al., 1986). Addition of 10 % rock phosphate to organic waste containing 10 % cow dung results in increase in phosphate solubilizing micro organisms.
7.Conclusion:
Vermicompost is best out of organic waste. On proper handing of the organic waste i.e., proper maintenance of certain physical and chemical properties of the organic waste, it can be converted into vermicompost, which will act as a conditioner for the soil health as well as a rich nutrient source for the crops.
Author contact address : -
SAMIR KUMAR SAHU,
EXECUTIVE DIRECTOR
MAYURBHANJ BIOLOGICAL RESEARCH (MBR)
MAYURBHANJ BIOLOGICAL RESEARCH (MBR)
BHANJPUR, BARIPADA, MAYURBHANJ, ORISSA, INDIA.PIN:757002
Cell: + 91-94372-399299
Cell: + 91-94372-399299
E.mail: mbrindia@gmail.com,
