VERMICOMPOSTING - TYPES, METHODS, ADVANTAGES AND DISADVANTAGES

Vermicompost (vermi-compost) is the product of the decomposition process using various species of worms, usually red wigglers, white worms, and other earthworms, to create a mixture of decomposing vegetable or food waste, bedding materials, and vermicast.

2. Vermicompostingisasoldaslifeonearth.
MichiganBiologyTeacher,MaryAppelhofarrivedattheideaofhome
vermicomposting.
Inthewinterof1972,shecreatedavermicompostingpitinherbasement.
Thetendoftheseasonsaw65lbsofgarbageconsumedandresultantworm
compostaidingimpressivevegetablegrowninhergarden.

3. EarthwormshavebeenontheEarthforover20millionyears.Inthistime
theyhavefaithfullydonetheirparttokeepthecycleoflifecontinuously
moving.Theirpurposeissimplebutveryimportant.Theyarenature’sway
ofrecyclingorganicnutrientsfromdeadtissuesbacktolivingorganisms.
Manyhaverecognizedthevalueoftheseworms.
Ancientcivilizations,includingGreeceandEgyptvaluedtherole
earthwormsplayedinsoil.TheEgyptianPharaoh,Cleopatrasaid,“Earth
wormsaresacred.”Sherecognizedtheimportantrolethewormsplayedin
fertilizingtheNileValleycroplandsafterannualfloods.

4. CharlesDarwinwasintriguedbythe
wormsandstudiedthemfor39
years.Referringtoanearthworm,Darwin
said,“Itmaybedoubtedwhetherthereare
manyotheranimalsintheworldwhich
haveplayedsoimportantapartinthe
historyoftheworld.”Theearthwormisa
naturalresourceoffertilityandlife.

5. “Vermicompostingisaprocessinwhichtheearthwormsconvertthe
organicwasteintomanurerichinhighnutritionalcontent.”
Vermicompostingisthescientificmethodofmakingcompost,byusing
earthworms.Theyarecommonlyfoundlivinginsoil,feedingonbiomass
andexcretingitinadigestedform.
Vermiculturemeans“worm-farming”.Earthwormsfeedontheorganic
wastematerialsandgiveoutexcretaintheformof“vermicasts”thatarerich
innitratesandmineralssuchasphosphorus,magnesium,calciumand
potassium.Theseareusedasfertilizersandenhancesoilquality.

6. Vermicompostingisamethodofpreparingenrichedcompostwiththeuseof
earthworms.Itisoneoftheeasiestmethodstorecycleagriculturalwastes
andtoproducequalitycompost.Earthwormsconsumebiomassandexcrete
itindigestedformcalledwormcasts.Wormcastsarepopularlycalledas
Blackgold.Thecastsarerichinnutrients,growthpromotingsubstances,
beneficialsoilmicrofloraandhavingpropertiesofinhibitingpathogenic
microbes.
Vermicompostisstable,finegranularorganicmanure,whichenrichessoil
qualitybyimprovingitsphysicochemicalandbiologicalproperties.Itis
highlyusefulinraisingseedlingsandforcropproduction.Vermicompostis
becomingpopularasamajorcomponentoforganicfarmingsystem.

8. Selectionoftherightspeciesofearthwormisveryimportantfor
vermicomposting.Thewholeprocessdependsmainlyonthevermicultureas
theircastingisourendproduct.
Thenutrientvalueofvermicompostdependsuponspeciesandtheirfeed
types.ThustherehasbeenincreasedattentionontheEisenia
fetidaandEudriluseugeniaefromtheEpigeicSpeciesofearthworms.
Theseareredwrigglersearthwormsknownassurfacefeeders.Bothare
potentialagentsthathavebeenwidelyusedinVermicompostingtechnology
becauseoftheircharacteristics.

9. Theygrowatawiderangeoftemperaturevaryingfrom0–40°C.However,
theoptimumtemperaturerangesfrom20-30°Cwhichhelpsinrapidgrowth
andmaturation.
Theseearthwormshaveahighrateoforganicmatterconsumption,
digestion,andassimilation.Theyhaveahighenvironmentalstresstolerance
ratecomparedtotheotherspeciesofearthworms.Andlastly,theshorterlife
cycleofthisspeciesalsoprioritizestheirpreferenceforvermicomposting
overotherspeciesofearthworms.
Thesewormsareintroducedattherateof3000to4000numbersperbed
sizeofonesquaremeter.

10. Moisture:60-70%ofthemoisturebelowandaboverangewormsdeath
occurs.
Aeration:50%Aerationfromthetotalporespace
Temperature:Rangebetween18°Cto35°C;insulationprovisionincase
thetemperaturedropstofreezingpoint.
pH:mustRangebetween6.5and7.5

11. Theredwormscanconsumetheirbodyweightintheformofavailable
organicmatterwithinadayprovidedwithsuitableconditions.
However,onaverage,itwilltakearound2Kgofearthwormstocomplete
therecyclingof1kgoforganicwastewithinaframeof24hours.
Thewormswithinthetopmoistlayerofbeddingwoulddisappearwithin
minutesintothebedding.

12. Theamountofproductionandthestructuresusedforcompostingdetermine
thedifferenttypesofvermicomposting.
Small-ScaleVermicomposting:Afarmercancollect5to10tonesof
vermicompostperyearwhenvermicompostingisonasmallscaletosuit
personalneeds.
Large-scalevermicomposting:Itiscarriedoutonacommercialscale,
producingbetween50and100tonnesoforganicwasteperyear.

15. Compostinginpitsthatare
5✕5✕3feetinsizeandmadeof
cementisthepitmethod.Thatch
grassoranyothernativematerials
areusedtocoverthestructure.
Thismethodisnotfavouredsince
itproducesmorewaste,haspoor
aeration,andcostsmoreto
produce.

16. HeapingabovethegroundThewastematerialisspreadonapolythene
sheetplacedonthegroundandthencoveredwithcattledung.Theefficacy
ofpitandheapmethodsofpreparingvermicompostunderfieldconditions
wascompared.Earthwormpopulationwashighintheheapmethod,witha
21-foldincreaseinEudriluseugeniaeascomparedto17-foldincreaseinthe
pitmethod.Biomassproductionwasalsohigherintheheapmethod(46-fold
increase)thaninthepitmethod(31-fold).Consequentproductionof
vermicompostwasalsohigherintheheapmethod(51kg)thaninthepit
method(40kg).

17. Byconstructingabedoforganic
materialmeasuring6✕2✕2feet,
compostingisdoneonthepucca
orkachchafloor.Thisapproachis
simpletomaintainanduse.

18. Thewedgemethodisa
vermicompostingtechniquethat
involvescreatingalong,shallow
windrowoforganicmaterialand
applyingfoodinthinlayersata45-
degreeangletooneside.The
wormswillmigratetowardthe
freshfood,leavingthealready
compostedmaterialbehind.

20. WINDROW METHOD
Windrowcompostingisusuallyconsideredtobethemostcost-effective
compostingalternative.Meanwhile,itmayalsohavethehighestfugitive
emissions.
Windrowcompostinginvolveslongrowsofcompostwheretheactualsize
andshapeofthewindrowaredependentonthefeedstocksandtype
ofCompostturner.Thepilesofmaterialsareplacedinlongrowsandturned
bymechanicalequipmenttomaintainoptimumconditions.Mechanical
turningisusuallydonewithafullhydrauliccrawlertypeturnermachine
speciallydesignedforturningwindrows.Thereasonforperiodicallyturning
thepilesistoensureadequateoxygenflowtothepile.

24. Windrowturningisimportantforspeedingupthecompostingprocess
becauseitbreakspreferentialairpathways,andbringsthematerialfromthe
outsidetothecenterforpathogenkill.
Windrowcompostingisasuitableoptionformanuremanagement,reducing
therisksofodor,soil,andwaterpollution.
Windrowcompostingbecomeseconomicallyandtechnicallyattractivedue
toitsrelativelysimpleequipmentrequirementsandgoodperformance
results,bringingeconomicandenvironmentalprofits.

25. Windrowcompostingissuitableforlargevolumesoforganicwaste
generatedbyentirecommunitiesandcollectedbylocalgovernments,and
foodprocessingbusinesses(e.g.,restaurants,cafeterias,packingplants)and
canevenhandlegreaseandanimalbyproducts.
Yardwaste,paperandcardboard,foodwaste,watertreatmentresiduals,
biodegradableplastics,pallets,sheetrock,andotherbiodegradablematerials
arenoproblemforwindrowcompostingprocess.

26. Acompostpitofanypracticalsizecanbebuiltinafield,garden,or
backyard.
Itcouldbeasinglepit,twopits,oratankmadeofbrickandmortarwiththe
appropriatewateroutletsinanysize(areasonablesizeis2mby1mby
0.75m).
Tocounteracttheantproblem,placeawatercolumninthemiddleofthe
vermipits’parapetwall.
The“fourchambers”pitwillmakeitsimpleforearthwormstogo
continuouslyfromonechamberthathasfullycompostedmaterialtothe
chamberthatcontainsthepre-processedtrash.

28. Topreparecompost,eitheraplasticoraconcretetankcanbeused.Thesizeofthe
tankdependsupontheavailabilityofrawmaterials.
Collectthebiomassandplaceitunderthesunforabout8-12days.Nowchopittothe
requiredsizeusingthecutter.
Prepareacowdungslurryandsprinkleitontheheapforquickdecomposition.
Addalayer(2–3inch)ofsoilorsandatthebottomofthetank.
Nowpreparefinebeddingbyaddingpartiallydecomposedcowdung,driedleaves
andotherbiodegradablewastescollectedfromfieldsandkitchen.Distributethem
evenlyonthesandlayer.
Continueaddingboththechoppedbio-wasteandpartiallydecomposedcowdung
layer-wiseintothetankuptoadepthof0.5-1.0ft.

29. Afteraddingallthebio-wastes,releasetheearthwormspeciesoverthe
mixtureandcoverthecompostmixturewithdrystraworgunnybags.
Sprinklewateronaregularbasistomaintainthemoisturecontentofthe
compost.
Coverthetankwithathatchrooftopreventtheentryofants,lizards,mouse,
snakes,etc.andprotectthecompostfromrainwateranddirectsunshine.
Haveafrequentchecktoavoidthecompostfromoverheating.Maintain
propermoistureandtemperature.

30. Continueaddingboththechoppedbio-wasteandpartiallydecomposedcowdung
layer-wiseintothetankuptoadepthof0.5-1.0ft.
Afteraddingallthebio-wastes,releasetheearthwormspeciesoverthemixtureand
coverthecompostmixturewithdrystraworgunnybags.
Sprinklewateronaregularbasistomaintainthemoisturecontentofthecompost.
Coverthetankwithathatchrooftopreventtheentryofants,lizards,mouse,snakes,
etc.andprotectthecompostfromrainwateranddirectsunshine.
Haveafrequentchecktoavoidthecompostfromoverheating.Maintainproper
moistureandtemperature.

31. Afterharvestingthecompost,thestorageofvermicompostingisthecrucial
aspectofmaintainingthebalancedphysical,chemical,andmicrobiological
propertiesofvermicompost.
Wemustensuretostoreitinaproperbreathablecontainerlikecardboard,
woodencrates,orasackmaintainingamoisturecontentof40-60%at
optimumtemperaturebyplacingitinacoolanddryspace.Andmost
importantlyallmaterialsusedandspaceofstoragemustbesterilizedto
avoidthecross-contaminationofmicroorganisms.
Ifstoredproperlythecompost’squality,nutrientcontent,shelflife,and
microbialactivitywon’tbecompromised.