VERMICULTURE:
A revolution is unfolding in vermiculture studies for vermicomposting of diverse organic wastes by waste eater earthworms into a nutritive “organic fertilizer” and using them for production of chemical free safe food in both quantity and quality without recourse to agrochemicals. Heavy use of agrochemicals since the “green revolution” of the 1960sboosted food productivity at the cost of environment and society. It killed the beneficial soil organisms and destroyed their natural fertility, impaired the power of ‘biological resistance’ in crops making them more susceptible to pests and diseases.
Chemically grown foods have adversely affected human health. The scientific community all over the world is desperately looking for an economically viable, socially safe and environmentally sustainable alternative to the agrochemicals. Several farms in world especially in North America, Australia and Europe are going organic as the demand for “organic foods” are growing in society.
Vermiculture is a process by which all types of biodegradable wastes such as farm wastes, kitchen wastes, market wastes, bio-wastes of agro based industries, livestock wastes etc. are converted while passing through the worm-gut to nutrient rich vermicompost. Vermi worms are used here act as biological agents to consume those wastes and to deposit excreta in the process called vermicompost. About 3000 species of earthworms are found world-wide. Out of which, approximately 384 species are reported to be found in India and their detail taxonomic studies have been done already (Julka, 1983).
BIOLOGY OF EUDRILUS EUGENIAE
Eudrilus eugeniae is a species of earthworm native to tropical west Africa and now widespread in warm regions, both wild and under vermicompost, also called the African night crawler.
GROWTH
Fecundity,
growth, maturation and biomass production were all significantly greater at
25ºC than 15º, 20º or 30º(25ºC= 77ºF
The growth of individual earthworms increased the
lower the population density, but the greatest overall earthworm biomass
production occurs at the highest population density. The greatest number of
cocoons per week and the number of hatchlings per cocoon are obtained at 25ºC.
Cocoon of Eudrilus eugeniae hatched in only 12 days at 25ºC, the earthworms
at these temperatures reached sexual maturity in as little as 35 days after
hatching.
LIFE CYCLE
Throughout its life cycle, Eudrilus eugeniae grew much more rapidly than Eisenia fetida, in similar environmental conditions. The West-African nightcrawler grows well at a temperature of 24-30ºC (75-86ºF).Maximum weight 2.5 grams occurs within 8-10 weeks. The African nightcrawler has a uniform purple-grey sheen and the posterior segments are evenly tapered to a point. The segments of the Brandling worm (Eisenia fetida) alternate reddish-orange and brown; the posterior segments do not taper, and the final segment is blunt.
ADHATODA VASICA
Adhatoda vasica, also known as malabar nut tree is part of the Acanthaceae plant family. It is a small evergreen, sub-herbaceous bush which grows commonly in open plains, especially in the lower Himalayas (up to 1300 meters above sea level), India, Sri Lanka, Burma and Malaysia (Shahriar, et al., 2013). The Vasica plant perennial, evergreen and highly branched with unpleasant smell and bitter taste, the plant lives for multiple seasons and retains its leaves throughout the year. It is a shrub 1.0m to 2.5m in height, with opposite ascending branches (Arabind, et al., 2013). It is a highly reputed plant used in Ayurvedic system of medicine for the treatment of various ailments of respiratory systems like bronchitis, asthma and it is also used in the treatment of malaria, dysentery and diarrhoea (Jain, et al., 1984) and has many other medicinal applications (2-4). Adhatoda vasica Linn. Also has anti-inflammatory, analgesic, diarrhoea, dysentery, antioxidant, hepatoprotective, sedative, antispasmodic, anthelmintic properties (Mulla and More, 2010), Antimicrobial activity (Sheeba and Mohan, 2012), Antidiabetic activity (Bhatt, et al., 2011) Wound healing effect (Vinothapooshan and Sundar 2010), Infertility (Ganguli, et al., 2010), Antiulcer (Vinothapooshan and Sundar 2011), Antibacterial (Kavitha, et al., 2012), Antihistaminic effect, moderate hypotensive activity, thrombopoietic activity(Mahajan, et al., 2010). Cardiac depressant, uterotonic and abortifacient. The leaves are found to activate the digestive enzyme trypsin. An extract of the leaves showed significant antifungal activity against ringworm.
IMPORTANCE OF VERMICOMPOST OBTAINED FROM VERMICULTURE
1) Red worm castings contain a high percentage of humus. Humus helps soil particles form into clusters, which create channels for the passage of air and improve its capacity to hold water. Presence of worms regenerate compacted soils and improves water penetration in such soils by over 50% (Ghabbour, 1973 and Capowiez, et al., 2009). US study indicate that 10,000 worms in a farm plot provides the same benefit as three farmers working 8 hours in shift all year round with 10 tons of manure applied in the plot (Li, 2005).
2) Humus is believed to aid in the prevention of harmful plant pathogens, fungi, nematodes and bacteria (Nielson, 1965).
3) A worm casting (also known as worm cast or vermicast) is a biologically active mound containing thousands of bacteria, enzymes, and remnants of plant materials that were not digested by the worms. In fact, the bacterial population of a cast is much greater than the bacterial population of either ingested soil, or the worm’s gut. Microbial activity of beneficial microorganisms in worm castings is ten to twenty times higher than that of in the soil and other organic matter (Edwards, 1995).
4) Castings can hold 2-3 times more water than their weight in soil. Worm casting do not burn root systems. The product can insulate plant roots from extreme temperatures, reduce erosion and control weeds. It is odourless and consists of 100% recycled materials. Vermicompost also has very “high porosity”, “aeration”, “drainage” and “water holding capacity” than the conventional compost and this again due to humus contents (Suhane, 2007).
5) Plant Growth Regulating Activity: Some studies speculated that the growth responses of plants from vermicompost appeared more like “hormone induced activity” associated with the high levels of nutrients, humic acids and humates in vermicompost (Atiyeh, et al., 2000), (Edwards, et al., 1988). Researches show that vermicompost use further stimulates plant growth even when plants are already receiving “optimal nutrition”. It consistently improved seed germination, enhanced seedling growth and development, and increased plant productivity significantly much more than would be possible from the mere conversion of mineral nutrients into plant available forms. Some studies have also reported that vermicompost contained growth promoting hormone “auxins”, “cytokinins” and flowering hormone “gibberellins” secreted by earthworms (Suhane, 2007), (Tomati, et al., 1987) and (Tomati, 1995).
CONCLUSION:
This technique also helps to conserve the bio diversity, which is the need of the hour. Apart from providing self employment opportunities for the weaker section, it also help in maintaining the environmental/ ecological balance.
MATERIALS AND METHODS:
COLLECTION OF EARTHWORM
Specimens of adult earthworm, Eudrilus eugeniae were collected in the Periyar Maniyammai College, Vallam. They were kept in earthen pots with substrate medium containing 50% partly decomposed cowdung 50% soil and were maintained under the laboratory condition for five days. Care was taken to see that the worms collected from the laboratory condition for five days. Care was taken to see that the worms collected from the site, did not experience any pesticide treatment, and adult worms with the size 16.5 to 27.4cm in length and 2.500-3.400gm in weight were used for the present study.
COLLECTION OF SOIL:
Dry soil was taken from the Nathankovil Village, Tamilnadu for present study. It was manually powdered using stone and mortar.
COLLECTION OF ADHATODA VASICA:
The waste material of Adhatoda vasica leaves were collected from Nathankovil, Village, Thanjavur District, Tamilnadu.
PARTIAL DECOMPOSITION OF ORGANIC WASTE:
An earthen pot with size of 54 cm in diameter and 35 cm in height was taken and used for the decomposition of A. vasica which was free from earthworm invasion. The tanks were filled with A. vasica leaves waste and poured with sufficient water. The tanks were closed with polythene sheets in order to avoid water evaporation and a possible release of foul smell during decomposition. Water was poured regularly in the tank after removing the polythene sheets and the tanks were closed again with the same polythene sheets for proper decomposition. Once in three days the decomposing materials were thoroughly mixed using wooden rod so as to ensure uniform decomposition. Ideal semi decomposed A. vasica in the form of wet leaf can be obtained only often 30 days decomposition. About 120kg of dry semi composed A. vasica leaves powder can be obtained during one process. These materials was then manually powdered with particle size less then 1mm as suggested by (Reinecke and Venter1985)and stored in a polythene bag.
PREPARATION OF SUBSTRATES FOR COCOON PRODUCTION STUDY:
Six sets of Five media with percent substrate ratios (PSR), 100, 75, 50, 25, and 0% were prepared using dry soil and powdered A. vasica leaves with volume by volume basis and mixed well. 4kgs of substrate in each percent ratio was taken in an earthen pot and sufficient volume of water was added into it to ensure optimum moisture condition as suggested. To assess the rate of cocoon production in the above said media, 12 adult earthworms were introduced into each pot. Six set of control (soil alone) as substrate experiments with 12 adult earthworms in each were also maintained simultaneously along with these media. Regular watering is a must for this culture study to provide optimum moisture condition to the earthworm cocoons produced by earthworms were collected and recorded once in a week for about a period of one month (09.10.2016 to 09.11.2016) survival of earthworms was also observed in the above said media during the course of study. Rate of cocoon production was calculated at daily as well as monthly basis.
CALCULATION:
The rate of cocoon production by earthworm was calculated and comparisons were made between control and experimental data.
RESULTS AND DISCUSSION:
COCOON PRODUCTIONSTUDY:
The rate of cocoon production and weight gain / loss of the epigeic earthworm Eudrilus eugeniae kept in the 0,25,50,75 and 100 PSR (Present Substrate Ratio) media prepared from partly decomposed Adhatoda vasica leaves waste with soil for 30 days were given in Table 1 and 2 respectively. The worms kept in 50, 75 and 100 PSR media for 30 days showed a gradual increase in their body weight up to 22 days thereafter, a gradual decline until the termination of this study. However, the worms kept in the same media (50, 75 and 100 PSR) after 30 days showed an increased value in their body weight over their respective initial weight. On the contrary, all the worms kept in 0 and 25 PSR media showed a gradual decrease in their body weight until the termination of this study and their respective percent weight loss values were 72.6 and 98.3 (Table 2). The worms kept in soil alone for 30 day though showed 100% survival value, only 5 cocoons were laid during the course of study due to less organic matters in the medium.