Biofertilizers types and application .pdf

Biofertilizers types and application

1. Biofertilizers: types, production
and application
By-Dr. Ekta Khare

2. Biofertilizers
•Biofertilizersisasubstancewhichcontainsliving
microorganisms,whichwhenappliedtoseed,plant
surface,orsoil,colonizestherhizosphereorinteriorofthe
plantandpromotesgrowthbyincreasingthesupplyor
availabilityofprimarynutrientstothehostplant.
OR
•Biofertilizersarecarrier- basedmicrobialinoculants
containingsufficientcellsofefficientstrainsofspecific
microoranisms, thathelpinenhancingthesoilfertilityby
fixingatmosphericnitrogen,solubilization/mineralization
ofphosphorusordecomposingorganicwastes,by
augmentingplantgrowthpromotingsubstanceswiththeir
biologicalactivities.

3. Types of biofertilizers (on the bases of
nature and function)
1.
Nitrogenfixing:Nitrogenismostabundantandubiquitousintheair,yetbecomes
alimitingnutrientduetodifficultyofitsfixationanduptakebytheplants.However,
certainmicroorganisms,someofwhichcanformvariousassociationswithplantsas
well,arecapableofconsiderablenitrogenfixation.Thesemicrobescanbe:
–Bacteria
•Freeliving:Free-livinginthesoileg.Azotobacter
•Associative:Livinginrhizosphere(associative/associated)without
endophyticsymbioses.Eg.Azospirillum
•Symbiotic:Havingsymbioticandotherendophyticassociationswithplants.
Eg.Rhizobia, Frankia
–Bluegreanalgae(Cyanobacteria):havebeenreportedtobehelpfulinenhancing
rice-fieldfertilityforthecultivationofriceinmanypartsoftheworld.BGAcan
furtherprovidenaturalgrowthhormones,172proteins,vitamins,andminerals
tothesoil.Eg.Anabaena, Nostoc,Tolypothrix,Cylindrospermumetc.
–Azolla:isafloatingpteridophyte,whichcontainsasendosymbiontthenitrogen-
fixingcyanobacteriumAnabaenaazollae. Azollaiseitherincorporatedintothe
soilbeforericetransplantingorgrownasadualcropalongwithrice.

4. 2.Phosphatesolubilizing:
Thephosphorus-solubilizingbacteria(PSB)canincreasephosphorusavailabilityto
plantsbydissolutionofboundphosphatesinsoilbysecretingorganicacids
characterizedbylowerpHintheirvicinity.Eg.Bacillusspp.,Paenibacillusspp.,
Pseudomonasspp.etc.
3.
Phosphatemobilizing:
Themycorrhizalfungiformobligateorfacultativefunctionalmutualisticsymbioses
withmorethan80%ofalllandplants,inwhichthefungusisdependentonhost
forphotosynthatesandenergyandinreturnprovidesaplethoraofbenefitstoits
host.Themyceliumofthefungusextendsfromhostplantrootsurfacesintosoil,
therebyincreasingthesurfaceareaformoreefficientnutrientaccessand
acquisitionfortheplant,especiallyfrominsolublephosphorussourcesandothers
likecalcium,copper,zinc,etc,eg.ectomycorrhiza(Laccariaspp.,Pisolithusspp.,
Boletusspp.,Amanitaspp.),endomycorrhiza(eg.arbuscularmycorrhiza- Glomus
sp.,Gigasporasp.,Acaulosporasp.,Scutellosporasp.,andSclerocystissp.)

5. 4.Mineral-SolubilizingBiofertilizers
–Potassiumsolubilizing:Certainrhizobacteriacansolubilizeinsolublepotassium
forms,whichisanotheressentialnutrientnecessaryforplantgrowth.Eg.
Bacillusedaphicus,B.mucilaginosus,andPaenibacillusglucanolyticus
–Silicateandzincsolubilizing:Anotherimportantmineraliszinc,whichis
presentatalowconcentrationintheEarth’scrust,duetowhichitisexternally
appliedasthecostliersolublezincsulfatetoovercomeitsdeficienciesinplant.
Certainmicrobescansolubilizeinsolublecheaperzinccompoundslikezinc
oxide,zinccarbonate,andzincsulfideinsoil.Similarly,microorganismscan
hydrolyzesilicatesandaluminumsilicatesbysupplyingprotons(thatcauses
hydrolysis)andorganicacids.Eg.Bacillussubtilis, Thiobacillusthioxidans,and
Saccharomycessp.
5.Plantgrowthpromotingrhizobacteria:Besidesnitrogen-fixing,phosphorus
andmineralssolubilizingmicrobes,therearemicrobesthataresuitabletobeused
asbiofertilizersastheseenhanceplantgrowthbysynthesizinggrowth-promoting
chemicalslikegrowthhormones(auxins,gibberellinetc.).Thesebacteriashows
morethanonemechanismofplantgrowthpromotionviz.nitrogenfixation,
phosphorussolubilization,productionofantibiotics,cytokinins,chitinase,and
otherhydrolyticenzymesandenhancementofsoilporosity.Eg.Achromobacter,
Alcaligenes,Arthrobacter,Actinoplanes,Azotobacter,Bacillus,Pseudomonas
fluorescens,Rhizobium, Bradyrhizobiumetc.

6. 6.CompostBiofertilizers:Compostisadecomposing,brittle,murkymaterial
formingasymbioticfoodwebwithinthesoil,whichcontainsabout2%(w/w)of
nitrogen,phosphorus,andpotassium,alongwithmicroorganisms,earthworms,
anddungbeetles.
•Themicrobialorganicsolidresidueoxidationcausestheformationofhumus-
containingmaterial,whichcanbeusedasanorganicfertilizerthatsufficiently
aerates,aggregates,buffers,andkeepsthesoilmoist,besidesprovidingbeneficial
mineralstothecropsandincreasingsoilmicrobialdiversity.
•Compostisproducedfromawidevarietyofmaterialslikestraw,leaves,cattle-
shedbedding,fruitandvegetablewastes,biogasplantslurry,industrialwastes,
citygarbage,sewagesludge,factorywaste,etc.
•Thecompostisformedfromthesematerialsbydifferentdecomposing
microorganismslikeTrichodermaviridae,Aspergillusniger,A.terreus,Bacillus
spp.,severalGram-negativebacteria(Pseudomonas,Serratia,Klebsiella,and
Enterobacter),etc.thathaveplantcellwall-degradingcellulolyticorlignolyticand
otheractivities,besideshavingproteolyticactivityandantibiosis(byproductionof
antibiotics)thatsuppressesotherparasiticorpathogenicmicroorganisms.
•Anotherimportanttype(vermicompost)containsearthwormcocoons,excreta,
microorganisms(likebacteria,actinomycetes,fungi),anddifferentorganicmatters,
whichprovidenitrogen,phosphorus,potassium,andseveralmicronutrients,and
efficientlyrecyclesanimalwastes,agriculturalresidues,andindustrialwastescost-
effectivelyanduseslowenergy.

7. Production of Biofertilizers
Bacterial
Solidcarrierbasedformulation
•Themassproductionofbiofertilizersinvolvesculturingofmicroorganisms,processingof
carriermaterial,mixingofcarriermaterialwiththebrothculture,andpacking.
•Theidealcarriermaterialsusedinthepreparationofbiofertilizersmustbecheaper,
locallyavailable,andeasiertoprocess;mustbenon-toxicandorganicinstructure(so
thattheyremainbiodegradable)withhighwater-holdingcapacity;andshouldcarry
higherbacterialcellsandsupporttheirsurvivalforlongerdurations.
•Thecarrierscanbeofvariousorigins(organic,inorganic,orsynthetic)andcanbe
classifiedintofourmaincategories:
–Soils:peat,coal,clays,lignite,inorganicsoil
–Plantwastematerials:charcoal,composts,farmyardmanure,cellulose,soybean
meal,soybeanandpeanutoil,wheatbran,pressmud,corncobs
–Inertmaterials:vermiculite,perlite,groundrockphosphate,bentonite,calcium
sulfate,polyacrylamidegels,alginatebeads
•
Inmanypartsoftheworld,inoculantsareformulatedusingpeat(soilcarrier). Peatis
madeofpartiallydecomposedfloraaccumulatedovertheyears.Itprovidesanutritive
anddefensivegrowthenvironmentofanextensivevarietyofmicroorganisms.

8. •Oncedried,peatisground,commonlytopassthroughatleasta250-μmsieve.
GenerallythepeatdepositshavealowpH,whichmustbecorrectedtopH6.5–7.0.
Thepeatisthensterilizedandanadequateamountofliquidinoculumisaddedtoit.A
finalmoisturecontentof40–55%isgenerallyacceptable.
•Inoculatedpeatisincubatedforacertainperiodoftimetoallowbacteria
multiplicationinthecarrier.Thisstep,alsocalledmaturingorcuringisofmajor
importancesinceitimprovesthebacteriasurvivalrateduringstorageandonseeds.
•Ofteninpeatstickingagentsareincorporatedthusenhancingitsuniformityof
coverageonseed.Theadhesivesusedincurrentagriculturalpracticesaredifferent
polymers:polysaccharides(suchasgumarabicorcarboxymethylcellulose),
polyalcoholderivatives,orcaseinatesalts.Importantprerequisitesare:
–nontoxictoseedormicroorganisms,
–easilydispersibleinwater
–offeringabetteradhesionandsurvivaltomicroorganismsonseed.
•Othermaterialsaddedtotheinoculantformulationincludemacro-and
micronutrients,carbonormineralsources,hormones,andevenfungicides.Theaimis
tosupplymicroorganismswithprotectiveand/oranutrientsource,toassurebetter
adhesiontoseedthusimprovingtheinoculantquality,tomaketheproductmore
stable,toinactivatethetoxins,ortoenhancethestrain(s)survivalduringstorageand
afterexposuretoenvironmentalstressconditions(hightemperature,desiccation).
•Packaging:Polythenebagsusedforpackagingshouldbeoflowdensitygrade(50-75
micron).

10. Liquidformulation(Bacterial)
•Solidcarrierbasedformulatonscanhavedisadvantagesof
possessinglowershelf-life,temperaturesensitivity,being
contaminationprone,andbecominglesseffectivebylow
cellcounts.Consequently,liquidformulationshavebeen
developed
•LiquidFormulationsuseliquidmaterialsascarrier,whichis
usuallywater,oilorsomesolventsinformofsuspension,
concentratesoremulsions.Mostpopularliquidinoculant
formulationscontainparticularorganism’sbroth10-40%,
suspenderingredient1-3%,dispersant1-5%,surfactant3-
8%andcarrierliquid(oiland/orwater)35-65%byweight.
Viscosityisadjustedatequaltothesettingrateofthe
particles,whichisachievedbytheuseofcolloidalclays,
polysaccharidegums,starch,celluloseorsynthetic
polymers.

11. Blue green algae production
1.Troughortankmethod
•Prepareshallowtrays(2mx1mx23cm)ofgalvanisedironsheetorpermanenttank.Thesizeofthetankcanbe
increasedifmorematerialistobeproduced.
•Spread4to5kgofriversoilandmixwellwith100gofsuperphosphateand2gSodiummolybdate.
•Pour5to15cmofwaterinthetrays.
•Inordertoavoidthenuisanceofmosquitoesandinsectsadd10to15gFuradongranulesormalathion,orany
other.
•Themixtureofsoilandwaterwillsettlewithin8-10hours.Atthistime,add200to250gmothercultureof
bluegreenalgaetothesurfaceofwater.Thendon’tdisturbwater.
•Thereactionofthesoilshouldbeneutral.IfthesoilisacidicthenaddCaCo
3inordertobringthepHofthe
soiltoneutral.
•Within10-15daysthegrowthofthebluegreenalgaewilllookhardflakesonthesurfaceofthewater/soil.
•Thiswaywaterinthetray/pitisallowedtoevaporateandthegrowthofthealgaeflakesisallowedtodry.
•Thesepiecesofalgalgrowtharecollectedandstoredinplasticbags.Inthiswayfromonesq.m.trayor/pit
abouthalftonneskgbluegreenalgalgrowthisobtained.
•Againaddwatertotraysandstairthesoilwell.Thenallowthealgaetogrowinthisway.Thistimeitisnot
necessarytoaddmothercultureofalgaeorsuperphosphate.Inthismanneronecanharvestgrowthofalgae
2-3times.Afterthiseffectofsuperphosphateandsoilisreduced.
2.PitMethod
•
Insteadoftroughsortankspitsareduginthegroundandlayeredwiththickpolythenesheettoholdthe
wateroronehalfcementplasteredtanks.Otherprocedureisthesameasinthetroughmethod.Thismethod
iseasyandlessexpensivetooperatebysmallfarmers.

12. 3.Fieldscalemethod
•Thefieldscaleproductionofbluegreenalgaeisreallyascaledupoperationoftrough
methodtoproducethematerialonacommercialscale.
•Demarcatetheareainthefieldforalgalproduction: -Thesuggestedareais40m
2
.
•Prepareabundwithearthsoastostorethewater.
•Floodtheareawithwatertoadepthof2.5cm.
•Thenapplysuperphosphate12kg/40m
2
.
•Tocontroltheinsect-pestsattach,applycarbofuran(3%granules)orFuradon250g40m
2
.
•AfterinoculationiInclayeysoils,goodgrowthofalgaetakesplaceinabouttwoweeksin
clear,sunnyweather,whileinloamysoilsittakesthreetofourweeks.
•Oncethealgaehavegrownandformedfloatingmatstheyareallowedtodryinthesunin
thefieldandthedriedalgalflake,arethencollectedinsunnybagsforfurtheruse.
•
Onecancontinuallyharvestalgalgrowthfromthesameareabyrefloodingtheplotand
applyingsuperphosphateandpesticides.
4.Nurserycumalgalproduction
•If320m
2
oflandareallottedtoprepareanursery,anadditional40m
2
alongsidecanbe
preparedforalgalproductionasdescribedabove.Bythetimericeseedlingsarereadyfor
transplantationabout15-20kgofalgalmaterialwillbeavailable.Thismuchquantityofalgal
masswillbesufficienttoinoculateoneandhalfhectaresofarea.
•Recommendationofalgalbiomassforfieldapplication-10-15kg/haoneweekafter
transplantingtheseedlings.

13. Azollaproduction
•Microplots(20m
2
)arepreparedin
nurseriesinwhichsufficientwater(5-
10cm)isadded.
•ForgoodgrowthofAzolla,4-20Kg
P
2O
5/haisalsoamended.
•OptimumpH(8.0)andtemperature
(14-30°C)shouldbemaintained.
•Finally,microplotsareinoculatedwith
freshAzolla(0.5to0.4Kg/m
2
).
•Aninsecticide(furadon) isusedto
checktheattackofinsects.
•Afterthree,weekofgrowthmat
formedbyAzollaisharvestedandthe
samemicroplotisinoculatedwith
freshAzollatorepeatthecultivation.

14. Mycorrhizaproduction
Ectomycorrhiza
–Ectomycorrhizagenerallyaregrowninglucose
containingmediumandproducedsporesareusedfor
inoculation.
–Puremyceliaculturesarepreferredastheysuppress
growthofpathogensandcontaminants.
–Ectomycorrhizalinoculantsmaybeformulatedusinga
carriermadeofvermiculiteand5–10%peat
moisturizedwithsaltsandglucosenutrientmedium.
–Thisformulationprovidesastrongbufferingcapacity
(keepingpHbelow6)andenhancestheproductionof
fulvicacidthatstimulatesgrowth.
–Formulationisthenmixedinnurserybedstoform
associationwithrootsofculturedplants.

15. ISOLATION MASS PRODUCTION
Arbuscularmycorrhiza
•Constitute a group of root obligate biotrophsthat can not grow in media that
why a different approach is in use for their production.

16. Application of biofertilizer
•Seedtreatment:Seedtreatmentisaveryeffective,economic,andmost
commonmethodimplementedforalltypesofbacterialinoculants.The
seedsaremixedanduniformlycoatedinaslurry(inoculantmixedwith
200mLofricekanjior1%jeggey)andthenshade-dried,beforebeing
sownwithin24h.Coatingoflimeafterrhizobiainoculanttreatment
enhancestheefficacy.
•Seedlingrootdipping:Thisapplicationiscommonforplantationcrops
suchascereals,vegetables,fruits,trees,sugarcane,cotton,grapes,
banana,andtobaccowhereseedlingrootsaredippedinawater
suspensionofbiofertilizer(nitrogen-fixingAzotobacterorAzospirillumand
phosphorus-solubilizingmicrobialbiofertilizer)forsufficientperiodof
time.
•Soilapplication:Inthispractice,biofertilizerisapplieddirectlytothesoil
eitheraloneorincombination.Someexamplesofbiofertilizersinwhich
soilapplicationisemployedareRhizobium(forleguminousplantsortrees)
andAzotobacter(fortea,coffee,rubber,coconuts,allfruit/agroforestry
plants),BGAandazollainricefield,mycorrhizainnurserybeds.

17. QUESTIONS
•Definebiofertilizers.Explaintheindustrialproductionofbiofertilizers.
Ans.Giveinshortaboutalltypes.
•
Whatarethetypesofbiofertilizers.Discusswithexample.
•Writeanessayonindustrialproductionofbacterialbiofertilizersandapplication
methods.
•WriteshortnoteonOrganicfertilizer.
Ans.Writecompostandvermicompost
•Writeshortnoteonphosphatemobilizingbiofertilizerproduction
Ans.Mycorrhiza
•
ShortnoteonBGAproduction.
•Shortnoteonazollaproduction