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the earthworms in organic waste management requires a detailed understanding of theeffect of the physicochemical properties of the substrate.The role of organic carbon and inorganic nitrogen for cell synthesis, growth, andmetabolism is important in all living organisms. To provide proper nutrition forearthworms during vermicomposting, carbon and nitrogen must be present in thesubstrates at the correct ratio. The usual practice is to arbitrarily add either a richnitrogenous material, or a rich carbonaceous material to the feed substrate, depending onthe situation, to correct for C/N imbalance. In addition, the conventional determination ofC/N ratio is not always based on the proportion of each nutrient that is available for theseprocesses, but on their absolute content in the substrate. More so, different earthwormspecies are impacted differently by C/N ratio and feed mixture type. Therefore, pilotstudies are necessary to establish optimal C/N ratio for a specific earthworm species anda specific feed mixture.Earthworm: a terrestrial annelid worm (class Oligochaeta); especially any of a family(Lumbricidae) of numerous widely distributed hermaphroditic worms that move throughthe soil by means of setae and feed on decaying organic matter. One important functionof earthworms is to plow the soil by burrowing through it. These macro-pores provide thesoil with passageways through which air and water can circulate. Without some kind ofplowing, soil becomes compacted, air and water can't circulate in it, and plant roots can'tpenetrate it easily.12
Introduction of earthworms to areas not previously populated has led to improvement ofsoil quality and productivity. Earthworm casts are sources of nutrients for plants.Lumbricids produced casts that contained 73 percent of the nitrogen found in a pasturesoil from the ingested litter; indicating both the importance of earthworms inincorporating litter nitrogen into the soil and the inefficiency of nitrogen metabolism byearthworms (Syers et al., 1979). Earthworms increase the amount of nitrogen mineralizedfrom organic matter in soil. Nitrogen-fixing bacteria are found in the gut of earthwormsand in earthworm casts, and higher nitrogenase activity, meaning greater rates of N-fixation, are found in casts when compared with soil (Simek and Pizl, 1989). Nitrificationis enhanced in earthworm casts, the ratio of nitrate-N to ammonium-N tends to increasewhen earthworms are present (Ruz Jerez et al., 1988).Earthworms may increase levels of metabolic activity in soils, as measured by the amountof CO 2 evolved, yet nematode abundance and microbial biomass may decrease (Yeates,1981; Ruz Jerez et al., 1988). This occurs because earthworms reduce the amount ofsubstrate available to other decomposers, and because earthworms ingest otherdecomposer organisms as they feed. This process would tend to accelerate nutrientcycling rates. Some common agricultural lumbricids are Allolobophora chlorotica, theAporrectodea caliginosa species complex (A. trapezoides, A. turgida, and A.tuberculata), and L. terrestris. Species common to organic rich habitats, such as E.foetida are rarely found (Lee, 1985).13
Page 1 and 2: Mekelle UniversityThe School of Gra
Page 3 and 4: AbstractVermicomposting is the proc
Page 5 and 6: AcronymsANRS-----------------------
Page 7 and 8: 4.2 DISCUSSIONS ...................
Page 9 and 10: Chapter 1: Introduction1.1 Backgrou
Page 11: ConclusionUSCIRF has and will conti
Page 15 and 16: 1.4 General objectiveThe objective
Page 17 and 18: segments of sexually mature individ
Page 19 and 20: scab fungus, spores of which are tr
Page 21 and 22: compaction caused by agricultural t
Page 23 and 24: 2.6 Palatability of the Substrata t
Page 25 and 26: circumstances. As Eisenia foetida t
Page 27 and 28: the field. Lumbricus terrestris is
Page 29 and 30: earthworms were added to soil made
Page 31 and 32: 2.14 Production of Earthworm CastsA
Page 33 and 34: sand, respectively (Borowski, 1995)
Page 35 and 36: A recent study found that earthworm
Page 37 and 38: Chapter 3: Materials and Methods3.1
Page 39 and 40: exchangeable capacity using ammoniu
Page 41 and 42: And the three ingredient equation f
Page 43 and 44: The four-ingredient equation for mo
Page 45 and 46: Without earthwormPredetermined mixW
Page 47 and 48: Chapter 4: Results and Discussions4
Page 49 and 50: Figure 2: Effects of C/N ratio on C
Page 51 and 52: Figure 4: Effects of C/N ratio on C
Page 53 and 54: 4.2 DiscussionsAddition of earthwor
Page 55 and 56: earthworm dead tissue, nitrogen exc
Page 57 and 58: esults were found by Ndegwa and Tho
Page 59 and 60: is bound in organic matter in a for
Page 61 and 62: Therefore, developing countries lik
Page 63 and 64:
Bostrom, U. (1986). The effect of s
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Gerard, B.M. and R.K.M. Hay. (1979)
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Marinissen, J.C.Y. Dexter, A.R. (19
Page 69 and 70:
Rao S, Subba Rao A, Takkar PN (1996
Page 71 and 72:
Simek, M. and V. Pizl. (1989). The
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www.vermico.comYeates, G.W. (1981).
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2: Calculated Mass of Ingredients u
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Ingredient % Moisture % Carbon % Ni
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Ingredient % Moisture % Carbon % Ni
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4: Data analysis using JMP modelTab
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Table 2. Oneway Analysis of Organic
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Table 3. Oneway Analysis of Availab
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Table 4. Oneway Analysis of Total N
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Table 5. Oneway Analysis of CEC (cm
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Table 6. Oneway Analysis of Ex. Ca
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Table 7. Oneway Analysis of Ex. K (
Page 95 and 96:
Table 8. Oneway Analysis of Ex. Mg
Page 97 and 98:
Table 9. Oneway Analysis of Ex. Aci
Page 99:
5: Summary of number of Earthworm f
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