EdibleSoil
Description:Studentswillcreateasoilprofileusingedibleingredients.
Purpose:Learnersexpandtheirknowledgeofthesoilprofilebymaking
‘dirtpudding’.
GradeLevel:K-8
Objectives:Learnerswillidentifythelayersofasoilprofile.
IndianaAcademicStandards:
BackgroundInformation:
Examplesofselectacademic
standardspossiblymetduringthis
Soiltakesmanyyearstoformfromastartingpointofbedrockorparent
activity.Additionalacademic
material,alayerofrockuponwhichsoilaccumulates.Asyearspass,
standardsmaybeachievedwith
goodqualitysoilwilldevelopfourormoredistinctlayers.Atthe
addedenrichmentactivities.
surfaceistheO-horizon,alayeroforganicmaterialthatisusually
composedtopartlydecomposed,alsocalledresidue,orleaflitter.Next
EarthandSpaceScience:1.2.1;
istheA-horizon,alsocalledtopsoil.Mostplantrootsgrowinthislayer
1.2.2;1.2.3;1.2.4;1.3.3;1.3.4;4.2.2;
anditholdsmostofthesoil’snutrients.TheB-horizon(subsoil)
7.2.6;8.2.6;
containssandandsilt,andperhapssomenutrientsthathavedripped
LifeScience:6.3.3
through(leached)fromthelayersabove.TheC-horizonispartially
brokendownbedrock.Thelastlayer,theR-horizonisbedrock.
Time:45minutes,plusset-up.
Materials:(perstudent)
Someclassificationsschemesaremorecomplexandaddotherlayers.
Clearplasticcup
ThedeepertheOandA-horizonsare,themorenutrientdense(richer)
Spoon
thesoilis.“Rich”,well-drainedsoilisverydesirabletofarmersbecause
1/8cup(2tbsp.)Candy-coated
itusuallyindicatesthatthecropswillyieldmore.Soilprofilesvary
chocolate(ex.M&MsorReese’s
greatly,eveninthesamefield,inthesametownship,countyandstate.
Pieces)
GoodIndianafarmlandhasanA-horizonthatis3-feetthick.Aneroded
½cupChocolatepuddingto
soilmayhavelittleornotA-horizon.Forsimplicityinthisactivitywe
representsubsoil.
1/8cup(2tbsp.)Crushedchocolate usetheterms:parentmaterial,subsoil,topsoilandresidueorleaf-litter.
sandwichcookies(ex.Oreos)1tsp.
Coloredsprinkles=organisms
SeeExplanationofSoilProfileonpage3formoredetailedexplanation.
1tbsp.Coconut
2Gummywormstorepresent
GettingStarted:
earthworms
1. Preparethepuddingaccordingtothedirectionsonthe
Yellow,brownorgreenfood
package.(Youmayalsochoosetopurchasepre-mixedpudding
coloring.
inalargecan,oftenavailableatfoodservicegrocerystoressuch
asGFS.Thefoodservicedirectorofyourschoolmaybeableto
Labels/Paper:
orderforyouaswell).
Parentmaterials
2. Placechocolatesandwich(ex.Oreos)cookiesintoasealed
Subsoil
plasticbagandcrushusingarollingpin.(Youcanalsousea
Topsoil
Organisms
foodprocessor).
Residueorleaf-litter
3. Addacoupleofdropsoffoodcoloringtothecoconutina
Earthworms
plasticcontainerorbag.Shakefor30-45seconds.Pour
coconutontopapertowelstodrive(about1hour).
INAITC
www.inaitc.org
EdibleSoil!
adaptedfromhttp://gen.uga.edu/gen_soil.html
1
ActivityDirections:
1. ReviewthelayersofasoilprofilefromLesson1ofthesoil
module.Availableat:http://gen.uga.edu/gen_soil.htmlTell
learnersthattheywillbemakingtheirownediblesoilprofile.
2. Discusseachlayerofsoilandwhateachingredientrepresents.
Demonstratehowtoconstructtheediblesoilprofile.
3. Placeeachsoillayeringredientbyit’sappropriatelayer.
• Candycoatedchocolate(ex.M&MsorReese’sPieces)=
Parentmaterials
• Chocolatepudding=subsoil
• Crushedchocolatesandwichcookies(ex.Oreos)=
topsoil
• Coloredsprinkles=organisms
• Coconut=residue
• Gummyworms=earthworms
4. Placetheappropriatemeasuringutensilwitheachofthesoil
horizoningredients.
5. Demonstratemakingthesoilhorizonsofyourediblesoil.
6. Followtherecipebelow.
• Place1/8cup(2tbsp.)Candycoatedchocolate(ex.
M&MsorReese’sPieces)inthebottomofanindividual
cup.
• Add½cupChocolatepuddingtorepresentsubsoil.
• Nextadd1/8cup(2tbsp.)Crushedchocolatesandwich
cookies(ex.Oreos)fortheprofile’stopsoil.
• Sprinklewith1tsp.Coloredsprinkles=organisms
• Nextadd1tbsp.Coconut=residue
• Finallyadd2Gummywormstorepresentearthworms
DiscussionQuestions:
1. Whatarethelayersofsoil?
2. Whattypesoforganismsliveinsoilandaidinsoil
production?
3. Whyare“rich”soilsdesirablebyfarmers?
INAITC
www.inaitc.org
EdibleSoil!
adaptedfromhttp://gen.uga.edu/gen_soil.html
2
ExplanationofSoilProfile
Allsoilstartswithaparentmaterialsuchasweatheredbedrock(e.g.limestone,sandstone,
gneiss,schist,etc.)orboulderstransportedbyglaciers.Thetypeofparentmaterialdetermines
thetypeoftexture(amountofsand,siltandclay)asoilwillhave,andthuswhetherthesoilisa
siltloam,siltyclay,sand,etc.
Subsoiltakeshundredsorthousandsofyearstobuild.Agentssuchasrainandgrowingplants
slowlybreaktheparentmaterialdownintosmallerandsmallerpiecesuntiliteventually
becomessubsoil.
Topsoilisatthesurfaceofthesoilandisnecessaryforplantgrowth.Assubsoilcontinuestobe
exposedtotheelementsofweathersuchasfreeze-thawcyclesandrain,itbeginstodevelop
horizonsorvisiblelayers.Asplantsandanimalsintheuppermostlayerdie,theirremains
becomeorganicmatterandmakeahealthydarkbrownorblacktopsoil.
Organismssuchasfungi,bacteria,earthwormsandplantrootsliveintopsoil.Theydecompose
manure,plantresidueandcroppests.Otherorganismsinthesoil“fix”nitrogenfromtheair
andmakeitavailabletohelpplantsgrow.
Residueisthestalks,stems,leavesoflastyear’scropthatisleftontopofthesoil.Conservation
tillageisasystemoffarmingwherethesoilisdisturbedaslittleaspossible(minimallytilled),
allowinglotsresiduetocoverandprotectthesoilsurface.
Earthwormsloveresiduebecauseitprovidesfoodforthemandmoderatesthetemperatureof
thesoil.Thepracticeofconservationtillagenotonlyprotectstheprecioustopsoilfromerosion
(wheresoiliswashedintoriversmakingthemdirty),butitencouragesmoreearthworms-and
themoreearthworms,thebetterthetopsoil!
Bacteriaaremicroscopic,single-celledorganisms.Ateaspoonofsoilgenerallycontainsover
100millionbacteria!
Fungiareusuallymulti-celledorganismsthatareneitherplantsnoranimals.Fungalcellsform
longchainscalledhyphaeandmayformfruitingbodiessuchasmoldormushroomstodisperse
spores.
Source:http://ctic.paqinteractive.com/CTIC%20HOME/ONLINE%20STORE/Free%20Download/
INAITC
www.inaitc.org
EdibleSoil!
adaptedfromhttp://gen.uga.edu/gen_soil.html
3
BuildingBetterSoil–TastetheDifference!
Ithasbeensaidthattheaveragepersonconsumesoverabushelofdirtintheirlifetime.
Doesn’tsoundtooappetizing,doesit?Althoughittakesalongtimetobuildrealsoil,you
canmakeafunvisualrepresentationofsoilinafewminutes.
Residue
ColoredCoconut
TopSoil
Crushedchocolate
cookies
Organisms
Sprinkles
Gummyworms
Earthworms
Bacteria
Fungi
Subsoil
Chocolatepudding
ParentMaterial
INAITC
www.inaitc.org
Candy-coated
chocolate
EdibleSoil!
adaptedfromhttp://gen.uga.edu/gen_soil.html
4