On line asse

  • View
    65

  • Download
    1

Embed Size (px)

DESCRIPTION

education

Text of On line asse

  • 1. INTRODUCTIONAbout 2,350 years ago Aristotle has said, Earthworms are intestines ofthe earth. Only in the twentieth century has the truth in this statementbeen verified and found correct. He was ahead of our times by two andhalf of millennia. Darwin was another one to state: No other creaturehas contributed to building of earth as earthworm.Vermiculture is basically the science of breeding and raisingearthworms. It defines the thrilling potential for waste reduction,fertilizer production, as well as an assortment of possible uses for thefuture.Vermicomposting is the process of producing organic fertilizer or thevermicompost from bio-degradable materials with earthworms.Composting with worms avoids the needless disposal of vegetative foodwastes and enjoys the benefits of high quality compost.The earthworm is one of natures pinnacle soil scientists. Earthwormsare liberated and cost effective farm relief. The worms are accountablefor a variety of elements including turning common soil into superiorquality. They break down organic matter and when they eat, they leavebehind castings that are an exceptionally valuable type of fertilizer.The humified composts and vermicomposts rapidly attain equilibriumwith the soil ecosystem without causing some of the major disruptionscommonly associated with raw organic wastes. These products arevaluable in agriculture as nutrient sources and in soil improvement.

2. Advantages of Vermiculture and VermicompostingEarthworms can break down organic matter very rapidly, resulting instable, nontoxic vermicomposts with a better structure, microbialcontent, and available nutrient content than composts. These have apotentially high economic value as soil conditioners or media for plantgrowth. Although the best final products and the shortest residencetimes are obtained by high-technology systems, the low-technologyones can be easily adapted and managed in small farms or livestockoperations. Vermicompost is a finely divided, peatlike material with alow C:N ratio, excellent structure, porosity, aeration, drainage, andmoisture-holding capacity, and it supplies a suitable mineral balance,improves plant nutrient availability, and could act as complex-nutrient-sourcegranules.Similarly to composting processes, vermicomposting reduces wastebulk density, and recent research also showed that it greatly reducespopulations of pathogenic microorganisms). It is generally acceptedthat the thermophilic stage during the composting process eliminateshuman pathogens, but it has been shown that human pathogens arealso eliminated during vermicomposting, probably by means of anantagonism mechanism.As an aerobic process, both composting and vermicomposting lead toN mineralization, but the presence of earthworms in vermicompostingincreases and accelerates the N mineralization rate. Moreover, thehumification rates that take place during the maturation stage are higherand faster during vermicomposting, resulting in a greater decrease ofbio-available heavy metals. There is circumstantial evidence that thefinal product may contain hormone-like compounds or plant growth 3. regula-tors that could accelerate plant growth and crop yields. The mainpurpose when applying composting and vermicomposting technol-ogiesto organic-waste management has been to decrease landfill disposal andto obtain value-added products that can be suitable forcommercialization. For this reason, many of the other applications ofthese processes have been disregarded and poorly studied. Therefore, weconsider these two processes of utmost importance for stabilizingorganic wastes, and at the same time solving or at least minimizing thoseenvironmental problems that could arise from their disposal 4. VERMICASTThe vermicast is a good organic fertilizer and soil conditioner. It isproduced by the decomposition of organic matter or agriculturalwastes. High-quality vermicast can be produced by worms such as thered wrigglers. It contains humus with high levels of nutrients such asnitrogen, potassium, calcium, and magnesium.The vermicast produced in the project was black and crumbly. It is richin nutrients. It will be used in gardens, landscaping, horticulture, andagriculture. The vermicompost itself is beneficial for the land in manyways, including as a soil conditioner, a fertilizer, addition of vital humusor humic acids, and as a natural pesticide for soil.Indeed, the use of red wriggler worms to produce vermicast has goodpotential for the production of organic fertilizer. 5. SubstratesThe substrates, or media where the red wriggler worms exist, wereubiquitous in the community. We applied several substrates in the vermibeds in our several substrate treatments. We used substrates such asmanure of livestock including carabao, chicken and goat; decomposedand partially decomposed plant wastes such as rice straw and rice hull;shredded moist newspapers; and vermicast containing red wrigglers.Manures of the carabao, chicken and goat contribute to the fertility ofthe soil by adding organic matter and nutrients, such as nitrogen, thatare trapped by bacteria in the soil. Meanwhile, rice straw is the onlyorganic material available in significant quantities to most rice farmers.About 40 percent of the nitrogen, 30 to 35 percent of the phosphorus,80 to 85 percent of the potassium and 40 to 50 percent of the sulfurtaken up by rice remains in vegetative plant parts at crop maturity. 6. COMPOSTING AND VERMICOMPOSTING PROCESSESComposting and vermicomposting are two of the best-known processesfor the biological stabilization of solid organic wastes. Compostinginvolves the accelerated degradation of organic matter bymicroorganisms under controlled conditions, during the organic materialundergoes a characteristic thermophilic stage 45C65C (113F149F) that allows sanitization of the waste by the elimination ofpathogenic microorganisms. Two phases can be distinguished incomposting: (a) the thermophilic stage, where decomposition takes placemore intensively and which therefore constitutes the active phase ofcomposting; (b) a maturing stage, which is marked by decreases in thetemperature to the mesophilic range and where the remaining organiccompounds are degraded at a slower rate. 7. OPEN COMPOSTING SYSTEMSA Windrow CompostingThis consists of placing the mixtures of different raw organic materialsin long, narrow piles or windrows that are turned mechanically on aregular basis to aerate them.B Forced Aerated Static PilesForced aeration systems are intended to supply air to the compostingmass using pressurized air systems,There are basically three ways tooxygenate the piles:1. Bottom SuctionThe air is drawn through the pile by the imposition of negative pressure.2. Bottom BlowingAeration is provided by blowing air through the pile.3. Alternative VentilationIn these systems bottom blowing aeration is alternated with bottomsuction aeration. 8. IN-VESSEL COMPOSTINGIn-vessel composting refers to a group of methods that confine the massto be composted inside a building, container, or vessel. In-vessel systemsare designed to promote rapid digestion rates by careful monitoring andcontrol of the compost-ing process; although these systems can producean end product more quickly, they are more complex and relativelycostly to build, operate, and maintain. There are a variety of in-vesselmethods with different combinations of vessels, aeration devices, andturning mechanisms.A Continuous Vertical reactorsUsually the materials are loaded up from the top of the reactor anddischarged from the bottom.B orizontal ReactorsThe materials are arranged along the length of the unit, and the heightnever exceeds 23 m (69 ft). 9. OPEN VERMICOMPOSTING SYSTEMSA Low-Cost Floor BedsThe traditional methods of vermicomposting have been based on beds orwindrows on the ground containing materials up to 45 cm (1.5 ft) deep,but such methods have numerous drawbacks. They require large areas ofland for large-scale production and are relatively labor-intensive, evenwhen machinery is used for adding materials to the beds, watering, andharvesting the products.B Gantry-Fed BedsAn important principle to improve the efficiency of processing oforganic wastes by earthworms is to add the wastes to the beds in thinlayers of 2.55.0 cm (12 in) at frequent intervals.C Raised Gantry-Fed BedsEarthworms are usually confined to the top 1015 cm (46 in) of thebed. The efficiency and rate of processing the wastes can beconsiderably increased by placing the bed above the ground.D Dorset Wedge-Style BedsThe design of this type of bed is quite different from the relativelyshallow flat beds described previously. Waste is added to the angledleading edge in shallow layers. 10. IN-CONTAINERVERMICOMPOSTINGA BinsOther systems refer to the use of bins or large containers, often stackedin racks.B Batch ReactorsMuch more promising techniques have used containers provided withlegs. 11. CONCLUSIONSThe Vermiculture and Vermicomposting activity is such a worthwhileand exciting venture,It is a substantial way of reducing wastes,producing fertilizers and maintaining the balance of the ecologicalenvironment. Vermicomposting can produce high-quality fertilizerswhich are better compared to other commercial fertilizers in the market;converts farm wastes into organic fertilizer, making it an environment-friendlytechnology; Vermiculture increases crop yield and lessensdependence on chemical fertilizers thus mitigating climate change; canbe made into a livelihood program and become a source of extra incomethrough selling the vermicast and also the vermi worms; 12. REFERENCE. http://en.wikipedia.org/wiSki/Earthworms.. http://agri.and.nic.in/vermi_culture.htm. APPLIED ZOOLOGY -ZOOLOGICAL SOCIET STUDY MATERIAL. SCERT SCIENCE BOOK