Incorporating Prairies into Multifunctional LandscapesEstablishing and Managing Prairies for Enhanced Environmental Quality, Livestock Grazing and Hay Production, Bioenergy Production, and Carbon Sequestration

PMR 1007 Revised February 2011

Prepared by: MeghannE.JarchowandMattLiebman DepartmentofAgronomy,IowaStateUniversity

Photography provided by: MeghannE.Jarchow

BradleyJ.Cook(wetland–page3) DepartmentofBiologicalSciences,MinnesotaStateUniversityMankatoJerryPeckumn(palepurpleconeflower–page22) PeckumnRealEstateandFarmsLoisWomble(femaledickcissel–page15) CarolinaBirdClub

Illustrations, visualizations, and figures by: AmyL.Dixon(hydrologyillustration–page6)

Biological-Pre-MedicalIllustration,IowaStateUniversityIowaDepartmentofNaturalResources(landusefigures–page2)

G.L.DrakeLarsen(landscapevisualization–page7) DepartmentofNaturalResourceEcologyandManagement,IowaStateUniversityJohnE.Weaver(rootillustration–page21) DepartmentofBotany,UniversityofNebraska

Publication layout by: TylerTeske DepartmentofAgronomy,IowaStateUniversity

Publication printing sponsored by:

Thank you to Steve Barnhart, Shane Ellis, Richard Pope, and two reviewers for their valuable feedback on previous versions of the publication.

…and justice for allTheU.S.DepartmentofAgriculture(USDA)prohibitsdiscriminationinallitsprogramsandactivitiesonthebasisofrace,color,nationalorigin,gender,religion,age,disability,politicalbeliefs,sexualorientation,andmaritalorfamilystatus.(Notallprohibitedbasesapplytoallprograms.)ManymaterialscanbemadeavailableinalternativeformatsforADAclients.Tofileacomplaintofdiscrimination,writeUSDA,OfficeofCivilRights,Room326-W,WhittenBuilding,14thandIndependenceAvenue,SW,Washington,DC20250-9410orcall202-720-5964.

IssuedinfurtheranceofCooperativeExtensionwork,ActsofMay8andJune30,1914,incooperationwiththeU.S.DepartmentofAgriculture.GeraldA.Miller,interimdirector,CooperativeExtensionService,IowaStateUniversityofScienceandTechnology,Ames,Iowa.

Contents

WhatIsaPrairie? 2-3

HowCanPrairiesBenefitMyFarm? 4-6

HowCanPrairiesBeIncorporatedintoFarms? 7

HowArePrairiesEstablishedandManaged? 8-11 SitePreparation 9 SelectionofSeedingMixes 10 PrairieSeedingandEarlyManagement 11

HowWillthePrairieAffectMyCrops? 12-13

WhyPrairies?WhyNow? 14

CanPrairiesBeUsedasPartofMultifunctionalLandscapes? 15-21 Using Prairies for Grazing Livestock and Hay Production 16-17 Using Prairies to Produce Biomass Feedstocks 18-19 Using Prairies to Sequester Carbon 20-21

Conclusions 22

WhatOtherResourcesAreAvailabletoMe? 23

References 24-25

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Tallgrassprairiesareathreatenedecosystem:lessthan5%remain.

LandcovermapsofIowain1850and1990fromtheIowaDNR.Notethatthe“grassland”categoryinthe1990landcovermaprepresentsprimarilypasturesratherthanprairie.

What Is a Prairie?Aprairieisatypeofgrasslandthatcontainsmostlyperennialplants.BeforeEuropeansettlement,mostofthecentralUnitedStateswascoveredwithprairies.Prairiesaregenerallyclassifiedbasedontheheightofthedominantgrassesandincludetallgrass,mixed-grass,andshortgrassprairies.Morethan95%ofalltallgrassprairieshavebeeneliminatedprimarilyduetoconversionofthelandforagriculture,whereasapproximately40%oftheshortgrassprairiesremainbecausethelandistoodryfornon-irrigatedagricul-ture,butissuitableforlivestockgrazing.Iowaisanextremeexampleoftallgrassprairieloss;lessthan0.1%oftheprairieremainstodayinthestate(SamsonandKnopf1994).

Althoughtallgrassprairieregionsreceivesufficientprecipitationtosupporttrees,treeswerehistoricallyexcludedfromprairiesbecauseoffireandruminantgrazing.Prairievege-tationisadaptedtofire;theabovegroundvegetationdies,buttheplantsareabletogrowbackrapidlyfromtheroots.Althoughsomespeciesoftree,suchasburoak,aretolerantoffireatmaturity,mosttreeseedlingsareintolerantoffire.Disturbancebyruminantssuchastrampling,grazing,andwallowingalsonegativelyaffecttreeseedlingestablish-ment.Removalofdisturbancestotallgrassprairiescanresultininvasionbytrees.Onceestablished,thetreesshadetheprairieplants,whichareadaptedtofull-sunconditions.

Prairieplantshaveextensiverootsystems.Soilsunderestablishedprairiescancontainmorethan10tonsofrootsperacrewithmostoftherootsoccurringasadensematwithinthetopfootofsoilandsomerootsgrowingtodepthsofmorethan8feet(Weaver1919).TherootsystemsofprairieplantsproducedtheMollisolsoilsthatarefoundunderprairies.Mollisolshavehighconcentrationsoforganicmatterinthesurfacehorizon,whichareoften2to3feetdeep.Thedeep,organic-matter-richsurfacehorizongivesMollisolshighinherentfertility.Itisthehighfertilityofthesoilsproducedbytallgrassprairiesthatmakesthelanddesirableforconversiontoagriculture.

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Wetlandswereonceaprominentpartofprairielandscapes,especiallyintheprairiepotholeregionofthenorthcentralUnitedStates.Wetlandsareecosystemsthatcontainstandingwaterorsaturatedsoileitherpermanentlyorseasonally.Althoughshallowpondsoftencometomindwhenthinkingaboutwetlands,mostwetlandsdonothavestandingwaterthroughouttheyear.Theseseasonalwetlandsarecalledephemeralwetlands.Almostallofthewetlandsinthetallgrassprairieregionhavebeeneliminatedthroughtheuseofsubsurfacedrainagetilesanddrainageditches.Forexample,almost90%ofthewetlandshavebeendrainedinIowa(MitschandGosselink2000).Locationsofformerwetlandscaneasilybeseeninthe“wetspots”inagriculturalfields.Drainedwetlandsarehighlydesirableforagriculturalproductionbecausethelandgenerallyreceivessufficientwaterandthesoilsarehighinorganicmatter.Yetfunctioningwetlandsprovideamyriadofcriticalecosystemservices,suchasgroundwaterrecharge,nitrateremovalthroughdenitrification,floodcontrol,carbonsequestration,andanimalhabitat.Unlikerowcropsthatarenotadaptedtogrowingundersaturatedsoilconditions,wetlandplantsthriveundertheseconditions,makingwetlandsoneofthemostproductiveecosystems.

Therearemanydifferenttypesofnon-prairiegrasssystems,suchaspastures,grassedwaterways,andriparianbuffers.Pasturesaregenerallyseededwithnon-nativecool-seasongrasses,suchasorchardgrass,timothygrass,andsmoothbromegrass,thatarenutritiousforlivestock.Cool-seasongrassesbegingrowingearlyinthespring,havehigherproteinconcentrationsthanwarm-seasongrasses,andhavestrongre-growthaftergrazing.Grassedwaterwaysareusedtoreducesoilerosionandwaterpollutioninrow-cropsystems,andaregenerallycomposedofthesamecool-seasongrassesaspastures.Riparianbufferscancontainprairiespecies,butareoftendominatedbynon-nativegrassessuchasreedcanarygrass.

Prairiesdifferfromthesesystemsintwomainways.First,prairiesareoftendominatedbywarm-seasongrasses.Warm-seasongrassesarelikelynotusedinsomeoftheabovementionedgrasssystemsbecausewarm-seasongrassesaregenerallyslowerestablishingthancool-seasongrasses.Warm-seasongrassesalsohavelowerproteinconcentrationsthancool-seasongrasses.Second,prairiescontainforbs(AKAwild-flowers).Somepasturesmaycontainforagelegumes,butprairiescontainadiversearrayofleguminousandnon-leguminousforbs.Theforbsareparticularlyimportantasfoodsourcesforinsectsandwildlife.

Wetlands as a Part of Prairie Systems

How Do Prairies Differ from Other Grass Systems?

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Nutrientpollutionreferstothecontaminationofwaterbodiesbyexcessnutrients,particularlynitrogenandphosphorus.AllofthelakesandriversintheCornBeltandNorthernGreatPlainsregionhavehighernitrogenconcentrationsnowthanbeforetheexpansionofrow-cropagriculture,andapproximately90%ofthelakesandriversinthesameregionalsohavehigherphosphorusconcentrations(Doddsetal.2009).Nitrogenandphosphorusarepollutantsinwaterbodiesbecausetheyleadtoexcessivealgalgrowth,whichshadesoutsubmergedplantsandcancausehypoxiczones(AKAdeadzones).Annualrowcropsarepronetonutrientlossesbecauseplantsarenotgrowingearlyinthespringwhennitrogenandphosphorusaremostsusceptibletomovingintowaterbodiesthroughleachingandsoilerosion,respectively.

Becausemostprairieplantsareperennials,theybegingrowingearlyinthespring.Thedeep,actively-growingrootsoftheprairieplantsareabletotakeupnitrogenasitisleachedthroughthesoilfromhigheronthelandscape.Forexample,50%lowernitrateconcentrationswerefoundinstreamsfromarow-cropagriculturedominatedwatershedwith25%prairievegetationthanasimilarwatershedwithoutsignificantprairievegetation(SchillingandSpooner2006).Phosphorus,ontheotherhand,isprimarilytransportedtowaterbodiesattachedtosoilparticles.Thereforereducingsoilerosionbyincorporatingprairiesintoagriculturallandscapescontributestoreductionsinphosphoruspollution.

Prairies Reduce Nutrient Pollution

How Can Prairies Benefit My Farm?Incorporatingprairiesbackontothelandscapecanprovidenumerousecosystemservices.Theseservicesarefunctionsprovidedbyecosystemsthataredesirabletohumans,suchaswastedecompositionandwaterpurification.Otherecosystemservicesprovidedbyprairiesincludesoilconservation,nutrientretention,habitatforanimals,andhydrologicstabilization.Theextenttowhichanecosystemserviceisprovidedbyaprairiedepends,however,onthesizeandlocationoftheprairie(seepage7forwaysprairiescanbeincorporatedintolandscapes).

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Thereisalmostnoerosionfromlandcoveredwithprairievegetationbecausethedensenetworkofprairierootsisincrediblyefficientatholdingthesoilinplace.Inadditiontopreventingsoilerosiondirectlyundertheprairie,prairiescanalsobeusedtoreducetheamountofsoilerosioninthelargerlandscape.Patchesorstripsofprairiecanbeinterspersedwithrowcropstoreducetheamountofsoilerosionfromthesystem.Placingstripsofprairieononly10%oftheareaofawatershedhasbeenfoundtoreducesedimentlossby90–95%whencomparedtowatershedswith100%annualrowcrops(Helmersetal.unpublished).Thisdemonstratesthatevenrelativelysmallpatchesofprairiescangreatlyreducetheamountofsoilerosion.Itisimportanttonote,however,thatwhileprairiestripscanreducetheamountofsoilleavingawatershed,theymaynotaffecttheamountofsoilerosiontakingplaceinrow-croppedareasadjacenttothestrips.

Prairies Reduce Soil Erosion

Beneficialinsectsareinsectsthatperformanecosystemservice.Twoecosys-temservicesprovidedbyinsectsinagriculturallandscapesarepollinationandsuppressionofpestinsects.

PollinationPollinationoccurswhenthepollenproducedinthestamen(themaleportionofaflower)isreleasedandfertilizesthepistil(thefemaleportionoftheflower).Pollenismostfrequentlytransferredfromthestamentothepistilviainsects;almost90%ofallfloweringplantsarepollinatedbyinsects.Wind-andself-pol-linatedplants,ontheotherhand,donotrequireinsectsforpollination.Grasses,includingcorn,areonegroupofplantsthatdonotrequireinsectpollinators,butmostotherplants,includingalmostallfruitandvegetablecrops,areinsectpollinated.Thereforemaintaininghealthypollinatorpopulationsisnecessaryformaintainingplantdiversityandfruitandvegetableyields.(Note–Althoughsoybeansarenotwindpollinated,soybeanplantsareusuallyselfpollinatedanddonotrequireapollinator.)

Prairiesprovideinsectpollinatorhabitatandfoodsources(pollenandnectar).Desirableinsecthabitatvariesamongspecies,butgenerally,prairiesprovidehabitatforpollinatorsbyhavingstandingabovegroundbiomassyearround.Theprairiebiomasshelpsmoderatethemicroclimatearoundtheinsects.Prairieforbsareimportantinprovidingfoodsourcesforinsects.Havingadiversityofforbsthatflowerthroughoutthegrowingseasonisnecessarytoensurethatthepollinatorspersist.

Suppression Of Pest InsectsInsectsthatpreyuponpestinsectsarecallednaturalenemies.Increasingthenumberandtypesofnaturalenemiespresentinandaroundagriculturalsys-temscanhelpreducethedamagecausedbyinsectpestsandcanreducetheamountofpesticidethatneedstobeappliedtoacrop.IthasbeenestimatedthatnativenaturalenemiessavecommodityfarmersintheUnitedStatesabout$4.5billionannuallyonpestcontrol(LoseyandVaughn2006).Thebenefitsprovidedbynaturalenemiescanbeincreasedbyincreasingtheyearroundfoodandhabitatforthesedesirableinsects.Justlikeinsectpollinators,naturalene-miesneedtobeprovidedwithpersistenthabitatandfoodresources.Althoughnaturalenemieseatpestinsects,thepestinsectsareusuallyonlypresentforpartofthegrowingseason.Thenaturalenemiesneedotherfoodsources,suchaspollenandnectarfromforbs,fortherestofthegrowingseason.

Usingprairiesashabitatforwildlifeandsongbirdsisoneofthemostcommonreasonsforprairiereconstructions.Infact,manyofthegovernmentprogramsthatprovidesubsidiesforhabitatrestorationsuchastheConservationReserveProgram(CRP)andWildlifeHabitatIncentivesProgram(WHIP)emphasizetheimportanceofusingperennialvegetationincludingprairiesforwildlifehabitat.Thedevelopmentoftheseedingmixesoftenspecificallyconsidersthefoodandhabitatrequirementsofoneormorewildlifeorsongbirdspecies.

Individualswhoreconstructprairiesforwildlifeandsongbirdhabitatmaydosotoprovidethemselveswithhabitatforhuntingandbirdwatching.Yetthereisalargemarketforprovidinghuntingandbirdwatchinghabitatforothers.IntheUnitedStatesin2006,hunters,fishers,andbirdwatchersspentmorethan$122billionpursuingtheseactivities(USFWS2006).

Prairies Provide Habitat for Wildlife and Songbirds

Prairies Increase the Number of Beneficial Insects

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Watermovesatthescaleofwatersheds.Awatershed,alsocalledacatch-ment,istheareaoflandthatnaturallydrainsintoonewaterbody–includingrivers,lakes,andwetlands.Incorporatingprairies,includingwetlands,intoawatershedcanstabilizethehydrologyofthewatershedbyreducingperiodsofpeakwaterflowandincreasingtheamountofwaterheldinthesoil.Prai-riesincreasetheporosityofthesoilbyincreasingtheamountofsoilorganicmatterandbyhavingextensiverootsystems.Thismakesthesoilunderprairiesactlikeasponge.Whenitrains,thesoilisabletotakeupandholdlargeamountsofwater.Betweenrainfallevents,thesoilisthenabletomoreslowlyreleasethewaterthansoilwithpoorerporosity.Soilsunderrow-cropproductionaremorepronetosurfacewaterrunoffandwaterseepingbelowtheplantrootingzone,whichreducesthewatersupplyforgrowingplantsandincreasesthemagnitudeofchangesintheflowofnearbywaterbodies.

Prairies Help Stabilize the Hydrology of a Watershed

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Hydrologicrelationshipsamongarestoredprairie,cornwithouttillage,andcornfollowingchiselplowing.Prairiesystemsholdmorewaterinthesoilandhavegreaterevapotranspirationratesthancornsystems,therebyreducingtheamountofwaterlostbelowtheplantrootingzone.Betweenthecornsystems,soilsinno-tillproductionholdmorewaterandloselesswaterbelowtheplantrootingzonethansoilsthathaverecentlybeenchiselplowed.DatabasedonBryeetal.(2000);figurebyA.L.Dixon.

BeforeEuropeansettlement,prairiesusuallyexistedinlargecontiguousblocksofthousandsofacres.Restoringlargeblockprairiesonanyonefarm,however,isprobablyunlikely.Prairiescanbeincorporatedintothelandscapeinnumerousways(seebelow).Prairiescanbeusefuladditionstothelandscapefromscalesoflessthananacretohundredsofacres.

How Can Prairies Be Incorporated into Farms?

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Grass Waterways

Sensitive Land

Wetlands

Livestock Grazing

Field Borders Large Tracts

Riparian Areas

On The Contour

Photorealisticvisualizationofmultipleusesforprairiesinmultifunctionallandscapes.FigurebyG.L.D.Larsen.

Becausethereareveryfewremainingprairies,thereisnoprairieseedbankinthesoilinmostplaces.InIowa,forexample,lessthan0.01%oftheoriginalprairieremainsasremnantprairiesandmostoftheprairiewasconvertedintoagriculturalproductionbyearlyinthe1900s.Inordertoreconstructprairies,prairieseedneedstobeaddedandweedsneedtobecontrolled.Onceaprairieisestablished,prairieplantsarecompetitivewithothernon-prairiespecies,butmostprairieplantsareslowtoestablish.Becauseofthis,theestablishmentphaseofprairiesisoneofthemostimportantphasesinprairiereconstruction.

Completeprairieestablishmentmaytakeuptofouryears,butestablishmentmaybemuchmorerapidifthesoilseedbankissmall.Onthefollowingpages,thethreemainstepsofestablishingaprairiearedescribedingreaterdetail.Thesestepsaresitepreparation,selectionofanappropriateseedmix,andseedingandweedmanagement.Formorecompleteinformationregardingtheprocessofestablishingaprairie,seetheresourcelistonpage23.

How Are Prairies Established and Managed?

Prairie Establishment Costs

Expenses Price ($/acre)

Landrent $100–3351

Seedcosts $45–15002

Sitepreparation(permanagement)

Tillage $8–20

Herbicide(product+application) $3–133

Seedingcosts(prairiedrill+cultipacking) $10–504

Weedmanagement/mowing(permow) $8–273

Comparison Among Most Common Prairie Seeding Times

1Edwardsetal.2009a2Duffy2007,PrairieMoon20093Edwardsetal.2009b4BlomgrenSeedandHabitatServices,personalcommunication

Time of seeding Pre-seeding

Tillage Plant favored Notes

Frost Seeding

FebruaryandMarch No Earlygerminatingplants(cool-seasongrasses,someforbs,somelegumes)

Seedstratificationoccursduringfreeze-thawcycles,whichalsoworkseedsintothesoil

Spring Seeding

April,May,andJune Yes Latergerminatingspecies(especiallywarm-seasongrasses)

Springherbicideapplicationortillagecanbeusedtokillfirstflushofweedseedlings

Dormant Seeding

NovemberandDecember

No Earlygerminatingplants(cool-seasongrasses,someforbs,somelegumes)

Seedingoccurswhentemperaturesarereliablylowerthanarenecessaryforseedgermination

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Governmentsubsidiesareavailabletooffsetupto90%oftheestablishmentcosts.

What Equipment Will I Need?(Not all will be needed for all restorations)

• Tillageequipment(e.g.fieldcultivator)• Herbicidesprayingequipment• Prairieseeddrillorbroadcastseeder• Cultipacker• Mowerwithcutheightupto10”

Site PreparationAppropriatesitepreparationisnecessarytokillexistingvegetation,dimin-ishthesoilseedandbudbanks,andmakethesoilconducivetoprairieseedgerminationandestablishment.Thelocationofthesitefortheprairierestora-tionwilllikelybechosenbasedonlandavailabilityandtheproposedusefortheprairie.Siteswithnoperennialvegetationandaminimalsoilseedbankareideal,andpreparationismostdifficultforsiteswithestablishedperennialvegetationwithanextensivesoilseedbank.

Theeasiestsitetoprepareislandthathasbeenpreviouslyusedfortilledannualrowcrops,especiallysoybean.Thesoybeanstubblewillprovidesomesoilcover,butwilldecomposereadily.Theweedsthataremostprevalentintilledannualrowcropsareannualweeds,andannualweedsarenotcompeti-tivewithprairieplantsovermultipleyears.Furthermore,theweedseedbankunderrowcropsislikelytobesmallbecauseofthefrequentmanagement(tillageand/orherbicides)usedtocontrolweeds.Iftheweedpressureislow,almostnositepreparationisneeded.Theprairieseedcanbeno-tilldrilledintothesoilorspreadoversoilafterlighttillage.Iftheweedpressureishigh,depletingtheseedbankisuseful.Thiscanbeaccomplishedbyusingmul-tipleroundsofsecondarytillagetoexposetheweedseeds,encourageweedgermination,andkillweedseedlings.Thesecondarytillageshouldoccurinthespringfollowingcropharvest,andtwotothreeroundsofsecondarytillageshouldbesufficienttoreducetheseedbank.

Unlikerow-cropsystemsthatincludetillage,theweedseedandbudbanksunderno-tillsystemsoftenhavemoreperennialspecies.Perennialweedscanbemorecompetitivewithprairieplantsthanannualweedsbecauseoftheirpersistenceonceestablished.Themoretheperennialweedseedsandplants,whicharethesourceofthebudbank,canberemovedfromthesite,themorerapidlytheprairiewillestablish.Theperennialweedscanbekilledusingeitherherbicidesortillage.Thenumberofperennialweedseedsintheseedbankcanbereducedbymultipleroundsofsecondarytillageorbysprayingherbicidesaftertheweedshavegerminatedthefollowingspring.Ifsecondarytillageisused,additionalweedseedsthathadbecomeburiedinthesoilmaybemovedtothesoilsurfaceandhavefavorableconditionsforgerminationandestablishment.

Landthatiscurrentlyunderperennialvegetation,suchaspasturesandabandonedfields,requiresthemostdiligentsitepreparationbecausetheestablishedperennialplantswillgenerallyoutcompetetheestablishingprairieseedlings.Itisimportantthattheestablishedplantsarekilledbeforetheprairieisseeded.Broadspectrumherbicides,suchasglyphosate,areusuallysuccessfulatkillingtheestablishedplants.Tillageislesslikelytobeeffec-tiveatkillingtheperennialplants.Althoughmanyoftheshootsoftheplantswilldieaftertillage,theplants’rhizomesmaybebrokenandspread,whichcouldincreasethebudbank.Theweedseedbankisalsolikelytobelarge,andrepeatedtillageorherbicidesprayingcanbeusedtokillemergingweedseedlings.Preparationofasitewithexistingperennialvegetationwilltakealmostoneyear.Sprayingherbicidesinthefallfollowedbyrepeatedherbicideapplicationsortillagethefollowingyearwillgreatlyreducetheweedpressureandencouragerapidprairieestablishment.

TOP: Tilled ground ready for seedingBOTTOM: Seeded and cultipacked tilled prairie

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Asprairierestorationshavebecomemorewidespread,prairieseedpriceshavedecreasedandtheavailabilityofseedhasincreased.Thecostofprairieseedmixescanvarybyordersofmagnitudedependingonthesourceoftheseedandthenum-berofspeciesintheseedmix.Thesourceoftheseedreferstothelocationwheretheseedcamefrom.Seedsourcecanbemostvariableforprairieplantsthathaveawiderange.Switchgrass,forexample,isfoundthroughouttheUnitedStates,andsourcesforswitchgrassseedcanrangefromTexastoNorthDakota.Itisidealtoselectprairieseedfromasourceclosetothesiteoftheprairierestorationorfromasourcewithsimilarenvironmentalconditions,suchasdaylengthandprecipitation.

Prairieseedcanalsobesoldascustomseedmixesorbulk-harvestedseedmixes.Customseedmixesaremulti-speciesmixturesinwhichtheseedfromeachspe-ciesisharvestedseparatelyandthedesiredquantityofeachspeciesisaddedtotheseedmix.Customseedmixesprovidegreaterflexibilityintheidentityandamountofspeciespresentintheseedmix.Furthermore,theseedofeachspeciescanbeharvestedatthetimeofpeakseedmaturityforthatspecies.Bulk-harvestedseedmixesareproducedwhenaprairieisharvestedwithmachinerysuchasacombineorbrushstripperandalloftheseedsthatarecollectedaresoldasonemix.Bulk-harvestingprairiesisoftenmoreeconomicalthancustommixingseedmixes,andbulk-harvestedseedmixescontainseedquantitiesandspeciescombinationsthatactuallyoccurredintheharvestedprairie.

Therichnessofspeciesandamountofeachspeciespresentinseedmixesishighlyvariable.Thecompositionofthespeciesmixwillvarydependingonthedesireduseoftheprairie.Some“prairie”seedmixescontainonlygrasses,butforbs(i.e.,wild-flowers)arenecessaryinordertohaveaprairieratherthanastandofgrasses.Grassseedisgenerallymoreinexpensivethanforbseed.Thereforeseedmixestendtobecheaperwhenfewerforbsareused.ThemostbasicseedingmixfortheConservationReserveProgram(CRP)containsonlytwoforbspeciesthatcompriselessthan5%oftheseedmix,andthesemixesoftencostlessthan$100peracre.Alternatively,forb-richseedmixesthatincluderarespeciescancostover$1,500peracre.Therearealargenumberofmoderate-diversityprairieseedmixesthatcostlessthan$200peracre.Thesourceandharvestmethodalsoaffectseed-mixprices.

Beforeplantingaprairieseedmix,itisimportanttodeterminewhetheranyoftheseedsrequirepre-treatmentorbeneficialmicrobes(suchasrhizobiaormycorrhizae).Pre-treatmentreferstoaprocessthattheseedsmustgothroughbeforetheyarereadytogerminate.Commonpre-treatmentsforprairieseedsincludecold,moiststratification;alternatingcold-moistandwarm-moistperiods;andscarification.Somecompaniesperformallofthepre-treatmentsontheseedbeforesellingtheseedmix,whereasotherseedsaresoldastheseedswereharvestedfromthefield.Manyofthepre-treatmentsrequiredwilloccurnaturallyiftheprairieseedsareexposedtothefreeze-thawcyclesofwinter.Thereforeappropriateseedpre-treatmentismostimportantwhentheprairieisseededinthespring.Beneficialmicrobesincluderhizobiabacteriathatformrootnodulesandperformnitrogenfixationinlegumesandmycorrhizalfungithatformsymbioticrelationshipswiththerootsofmanyprairieplants.Mostsoilswillcontainrhizobiaandmycorrhizae,butifthesoilhasbeenheavilydisturbedwithchemicalsorhashadthetopsoilremoved,addingrhizobialandmycorrhizalinoculums,whichcanbepurchasedwiththeprairieseedmixes,willensurethattherearesufficientbeneficialmicrobespresent.

Selection of Seeding Mixes10

Prairiescanbeplantedeitherbyhandorbyusingmechanicalseedingequip-ment,butmechanicalseedingequipmentisnecessaryformostplantingsthatarelargerthanoneacre.Broadcastseederssuchasmanurespreaderscanbeusedtoseedlargeareas.Onedisadvantageofbroadcastseedersisthatsmoothseedsmayfallintothebroadcastermorerapidlythanfluffyseedsresultinginunevenspreadingoftheprairieseedacrossthesite.Prairiedrillseeders,suchasTruax®drills,arespecificallydesignedforplantingprairieseed.Thedrillshavetwosetsofseedboxessothatthesmoothseedcanbeseparatedfromthefluffyseed,whichpromotesmoreevenseeddistribution.

Unlikecropseeds,whichhavebeenbredtobelargerthanseedfromtheirnativeprogenitors,mostprairieseedisrelativelysmall,andtheseedsmustbeplacednearthesoilsurface.Theabove-mentionedseedingmethodsallplacetheprairieseedsatornearthesoilsurface.Yettheseedsmusthavegoodseed-to-soilcontacttoallowtheseedstoestablishsuccessfully.Iftheprairieisseededinthespring,acultipackercanbeusedafterseedingtopresstheseedsintothesoilsurface.IftheprairieisseededbetweenNovemberandMarch,thefreeze-thawcyclesinthesoilwillworktheseedsufficientlyfarintothesoilforgoodseed-to-soilcontact.

Prairieseedlingsestablishmuchmoreslowlythanmanyother,lessconservativeplants.Mostprairieseedlingsinvestagreatdealofenergyinproducingrootsratherthanshoots,whichmakesprairieseedlingsverysusceptibletobeingoutcompetedforlightbyweeds.Oneofthebestmethodstopreventtheprairieseedlingsfrombeingoutcompetedforlightisfrequentmowingthroughoutthefirstgrowingseason.Theprairieshouldbemowedeverytimetheweedsaretallerthanapproximately12”andthemowershouldbesettoacutheightofapproximately6”.Ifweedpressureishigh,theprairiecanbemowedduringthesecondgrowingseasonalso,butthecutheightduringthesecondyearshouldbe8”to10”.

Fireisanothereffectiveweedcontrolmethodinestablishingprairiesbecauseprairieplantshaveevolvedtotoleratefirewhereasmanyweedspecieshavenot.Prairiescanbeburnedassoonasthespringofthesecondgrowingseasonifsufficientdeadbiomassispresenttofuelthefire.Springfiresareoftenusedforweedcontrolbecausemanyweedsbegingrowingimmediatelyinthespringwhereasmanyoftheprairieplants,suchasthewarm-seasongrasses,begingrowinglaterinthespring.Fireisanimportantmanagementtoolthroughoutthelifeoftheprairie,particularlyiftheprairiedoesnothaveothertypesofdisturbance,suchasmowingorgrazing.Withoutregulardisturbance,woodyvegetationwillbegintoinvadetheprairie.

Prairie Seeding and Early Management11

How Will the Prairie Affect My Crops?

No,mostprairieplantswillnotbecomeweedsincropfieldswhereannualcropsaregrown.Prairieplantscanbecompetitiveoncetheybecomeestablished,butasdiscussedonpage11,mostprairieplantsgenerallytakemultipleyearstobecomeestablished.Thereforeonlandthatisregularlytilledorwhereherbicideisappliedatleastannually,itisunlikelythattheprairieplantswillbecomeestablished.Prairieplantshavethepotential,however,tobecomeestablishedinno-tillfieldsifherbicidesarenotused.Prairieplantsgenerallyneedfullsun,andareunlikelytobecomeestab-lishedunderaclosedcropcanopy.

Will the Prairie Plants Become Weeds?

Prairiesmayharborsomeproblematicweeds.Duringtheestablishmentyearsofaprairie,theprairieislikelytocontainmanyannualweeds,suchasfoxtail,lambsquar-ters,horseweed,velvetleaf,andragweed(giantandcommon),allofwhichareweedsinannualcroppingsystems.Iftheprairieismowedfrequentlyduringtheestablish-mentyears,theamountofannualweedseedthatisproducedandspreadtotheneighboringcroplandcanbeminimized.Iftheweedseedbankislowonthesitewheretheprairieisestablished,thepotentialforweedseedspreadisevenlower.Astheprairiebecomesestablished–afterthefirstorsecondyeardependingontheex-istingseedbank–thenumberofannualweedswillgreatlydecrease,andtheprairieshouldnolongerbeasourceofannualweedsforneighboringcropland.

Duringtheestablishmentyearsandbeyond,theprairiemaybesusceptibletoinva-sionbyperennialweeds,whichcouldthenspreadintoneighboringcropland,butperennialweedsaregenerallywellcontrolledinannualrowcropsthroughherbicideapplicationsandtillage.OneofthemostproblematicperennialweedsinprairiesisCanadathistle,whichisanoxiousweedthroughoutalmostalloftheUnitedStates.Canadathistleisahighlycompetitiveplantthatcantolerateawiderangeofcondi-tions,andbecauseitisaperennial,Canadathistlecancompetewithprairieplants.ThebestmanagementstrategytocontrolCanadathistleistoeliminateallestab-lishedplantsbeforeplantingtheprairie.Thismayincluderepeatedherbicidespraysortillage(seepage9).MowingduringtheestablishmentyearsofaprairieisalsoaneffectivewaytocontrolCanadathistle.Afteraprairieisestablished,spotsprayingwithherbicidesisaneffectivestrategyforsuppressingCanadathistle.

Thesizeandshapeoftheprairiewillalsoaffecttheweedinessoftheprairie(seepage7fordescriptionsofdifferentprairieconfigurations).Prairieedgesareweedierthantheinteriorsofprairies.Thereforelongandnarrowstripsofprairieswillbemostlyedgeandwilltendtohavemoreweedsbecausethetransitionzonebetweenlandmanagedforannualrow-cropproductionandtheprairiewilllikelybefrequentlydisturbedthroughtillageandherbicidespraying.

Will the Prairie Harbor Problematic Weeds?

12

How Will the Prairie Affect My Crops?

13

Plantingprairiesaroundrowcropswillgenerallybebeneficialtothecropbyincreas-ingthenumberofnaturalenemies(seepage5).Itisunlikelythattheprairiewouldbeasourceofcropdiseases(bacteria,viruses,orfungi).Manybacteriaandvirusesareveryhostspecificandareunlikelytobeabletoinfectboththeprairieplantsandrowcrops.Thechangeinplantstructurebetweenacropfieldandprairiewouldlikelybebeneficialforreducingthehumiditythatoftenleadstofungaldiseasesinrowcrops.Theprairiecouldpotentiallyprovidehabitatforcroppests,particularlystalkborersandgrasshoppers,buttheeffectofthepestsonthecropwouldlikelybelimitedtothefirstfewrowsadjacenttotheprairie(R.Popepersonalcommunication).

Will the Prairie Be a Source of Diseases or Pests?

Establishedprairiesrequirelittlemanagement,butdependingonthedesiredusefortheprairie,somemanagementmaybeneeded(seepages14-21foradiscus-sionofprofit-gainingusesofprairies).Duringtheestablishmentyear(s)oftheprairie,however,thesitewillneedtobepreparedandtheprairiewillneedtobeseededandmanaged(seepages8-11).Thereis,however,agreatdealofflexibilityinthetimingoftheseactivities.

Will Management of the Prairie Conflict with Management of Crops?

Convertingaprairiebacktorowcropsisrelativelyeasy.Herbicides,suchasglypho-sate,willkilltheprairieplants,andthelandcouldthenbeeithertilledorusedforno-tillcropproduction.Someprairieseedsmaygerminateinsubsequentyears,butasdescribedpreviously,theseedlingscanbeeasilykilledwithtillageorherbicides.Prairieplantsproduceextensiverootsystems,however,andhavealargeamountofinternalnutrient(especiallynitrogen)cycling.Thereforeadditionalfertilizermayneedtobeappliedtheyearaftertheprairieiseliminateduntiltheprairierootsbegintodecomposeandthenutrientsbecomeavailableforthecrop.

Althoughitiseasytogetridofaprairie,almostallofthecostinhavingaprairieisincurredduringtheestablishmentyear(s)(seepage8).Manyofthegovernmentprogramsthatprovidecostsharingforprairieestablishmentrequirethelandownertocommittoleavingthelandinprairieforaspecifiednumberofyears(rangingfrom10yearstoapermanenteasement).Iftheprairieisremovedbeforethattime,thelandownermustrepayallorpartofthecost-sharingallotment.

Itisimportanttorememberthattheprairiewilllookweedyduringtheestablishmentyear(s).Decisionstoremovetheprairieshouldbedelayeduntilafterthethirdgrow-ingseason.

What If I Decide I Don’t Want the Prairie? Can I Get Rid of the Prairie?

Therearelikelytobesignificantchangesinagricultureinthenearfutureduetochangesinfossil-fuelpricesandavailability,pollutionregulation,andclimaticfactors.Annualrow-cropagricultureisheavilydependentoninexpensivefossil-fuelenergyforfuelformachineryandgraindryingandfertilizerandpesticideproduction.Asfossilfuelsbecomemorelimiting,different–andlikelymoreex-pensive–energysourceswillhavetobeused,whichwilldecreasetheprofit-abilityofrowcrops.Ifgreenhousegasemissionsandnitrogenandphosphoruspollutionbecomeincreasinglyregulated,theproductionandleakageofthesecompoundsintotheenvironmentfromannualrowcropswillintroducenewcostsforfarmers.Globalclimatechangewillalsoaffectagriculturalpracticesbyalteringtheclimate,butpotentiallymoreimportantlybyincreasingthefrequen-cyofextremeweatherevents,suchasflooding,drought,anduntimelyfrosts.

Diverseprairiesaremoreresilientsystemsthanmonoculturesofannualrowcrops.Resiliencereferstotheabilityofasystemtoresistdamagefromad-verseconditionsandreboundrapidlyifthesystemisdamaged.Diverseprairiesareabletoresistdamagefrompotentiallyadverseconditionsbecausemultiplespeciesarepresentatalltimes.Thereforeifoneparticularspeciesisdamaged–bydiseaseforexample–otherspeciesarepresenttobecomemoreabun-dantastheaffectedspeciesdeclines.Monocultureslackthisfeaturebecauseitislikelythatallplantswillbeaffectedbytheadverseconditionsimilarlyasallplantsarethesamespecies.Prairiesalsoreboundrapidlyfromdamage.Forexample,iftheabovegroundpartsoftheplantsaredamaged,therootscontainlargestoresofenergyfromwhichnewabovegroundbiomasscanbeproduced.Mostprairieplantsaremuchmoreconservativethanannualrowcrops;theyhaveextensivestoresofresourcesbelowgroundratherthaninvestingmostoftheirenergyintoabovegroundbiomassproduction.

Why Prairies? Why Now?

Soilunderrow-cropproduction(left)andremnantprairie(right).

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Can Prairies Be Used as Part of Multifunctional Landscapes?Thedeep,richsoilsproducedbytheprairiehavebeenthecauseofthenearextinctionoftheprairie;mostofthetallgrassprairiehasbeenconvertedintoagriculture.Insomedrierpartsofthecountrythathavemixed-andshortgrassprairies,however,theprairieshaveremainedbecausethelandismoreconducivetograzingthanrow-cropproduction.Thereforethereisalonghistoryofusingprairiesforlarge-scale,profit-gainingpurposes,butusingtallgrassprairiesforprofit-gaininguseshasnotbeenadoptedonalargescalebecausehigherproductivitycanbeobtainedwithannualrowcropsusingintensivemanagementandlargeinputsoffertilizerandpesticides.

Therearemultipleprofit-gainingusesfortallgrassprairiesthatareenvironmentallybeneficialandmaybecomeeconomicallycompetitivewithannualrowcropsinlightoffuturechangesinagriculture(see“WhyPrairies?WhyNow?”).Thefollowingthreeprofit-gainingusesforprairieswillbediscussed:

• Livestockgrazingandhayproduction(pages16-17)• Biomassfeedstockproduction(pages18-19)• Carbonsequestration(pages20-21)

15

Using Prairies for Livestock Grazing and Hay Production What Is It?Tallgrassprairiesevolvedwithfireandruminant,especiallybison,grazing.Thesedisturbancespreventedtheprairiefrombecomingdominatedbywoodyvegetation.Bisongrazingalsohelpedmaintainprairiediversitybecausebisonpreferentiallyeatwarm-seasongrasses,whicharethedominantprairieplants(Collinsetal.1998).Itislikelythatthehistoricpatternsoffireandbisongrazingwerepatchyandsporadic.Grazinglivestockorhayingtheprairiecanactaseffectivesubstitutesforfireandbisongrazing,andbothcanbemanagedtobepatchyandsporadic.

Grazinglivestockonprairieinrotationalorhigh-intensitygrazingsystemscanbeaneffectivemeansofmaintainingprairiediversitywhileproducinghigh-qualitylivestockmeatordairyproducts.Inrotationalandhigh-intensitygrazing,livestockaremovedfrequently,frommultipletimesperdaytoonceperoneortwodays,throughsmallpaddocksofprairie.Thelivestockconsumemostoftheavailablestandingbiomasswhileinthepaddock,butthepaddockisthenallowedtoregrowwithoutanylive-stockdisturbanceformultipleweekstoawholeyear.Theseformsofgrazingaremanagementintensive,butcloselymimichistoricprairiedisturbances.

Producingprairiehayisanothermethodofproducingavaluableproductwhilestillmaintainingprairiediversity.Prairiehaycanreceivepricepremiumsbecausethelegumesandforbsintheprairieprovidetracenutrientsthatmaynotbefoundinotherhays.Determiningwhentoharvestaprairieforhayisacompromisebetweenmaximumforagequalityandmaximumforagequantity.PeakprairieforagequalityoccursinJune,whereasmaximumabovegroundbiomassoccursearlyAugust.Itisrecommendedforprairiehaytobeharvestedinmid-tolateJuly,andforprairiehaytoonlybeharvestedonceperyearinordertomaintainthevigoroftheprairieinsubsequentyears.

Expenses Price ($/acre)

LandrentLandcurrentlyinrowcrops $147–2011

Landcurrentlyinpasture $35–771

Calfpurchase(@$1.08/lbfor525lbcalf;1.4calves/acrestockingrate)2

$8023

FertilizationNitrogen(@$0.68/lbfrom0–150lbN/acre) $0–1024

Phosphate(@$0.90/lbfrom0–50lbphosphate/acre) $0–454

Potash(@$0.72/lbfrom0–50lbpotash/acre) $0–364

Application $2–185

InfrastructureOthernon-pasturecosts6

$93

$163

Labor(@$14/hrand1hr/calf) $203

Economics - Costs (Livestock Grazing) For haying estimates see page 18.

1Edwardsetal.2009a2Includesa1%deathlossrate3Ellisetal.20094DuffyandSmith20095Edwardsetal.2009b6Includesveterinaryandfixedandvariablemachineryandequipmentcosts

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What Would a Grazing Prairie Look Like?Althoughprairiesinthetallgrassprairieregionarenamedfortheconspicuouswarm-seasongrassesthatareoftendominant,thecompositionandproductivityofprairiescanvarygreatly.Thedesirablespeciescompositionofaprairiewilldependonthelocationofandplanneduseforthatprairie.Theeffectsofthemanagementoftheprairie,suchaslivestockgrazingorhaying,alsoneedtobeconsideredwhenplanningthespeciescompositioninordertoensurethatspeciestolerantoftheparticularmanagementregimearechosen.

Ifaprairieisusedforrotationalorhigh-intensitygrazing,theprairieessentiallybecomesasetofmini-prairies,whicharethepaddocks,becausedifferentprairiespecieswillbedesirableindifferentpaddocks.Grasseswilllikelybedominantcomponentsofallofthepaddocksbecausegrassesarehighlyproductiveandaredesirableforagesforlivestock,buttherelativeamountsofcool-seasongrassesversuswarm-seasongrasseswilldependonthedesiredgrazingtimeforthepaddock.Nativecool-seasongrassesgenerallyhavehigherre-growthratesaftergrazingthanwarm-seasongrasses,andthegrowthofcool-seasongrassesisgreaterthanthatofwarm-seasongrassesinthespringandfall.Therefore,somepaddocksshouldbeplantedwithhigherconcentrationsofcool-seasongrassesthanmightotherwisebeusedinaprairiereconstruction,andthosepaddockscanbegrazedinthespringandfall.Theremainingpaddockscanbeplantedwithamixdominatedbywarm-seasongrass,andthosepaddockscanbegrazedinthesummer.Thepaddockgrazingordershouldbechangedyearlysothatthesamepaddockisnotbeinggrazedatthesametimeeveryyear.Paddocksshouldnotbegrazedmorethantwotimesinanyoneyearandgenerallyshouldbegrazedonlyonceperyear,especiallythosepaddocksdominatedbywarm-seasongrasses.

Inprairiesthatarehayed,thecompositionoftheprairiemaybemorevariable,andtheexpectedmarketforthehaymaybeimportantindeterminingthespeciescomposition.Forexample,bigbluestemcanbeaparticularlydesirablecomponentinhorsehay.Althoughharvestingtheprairieinmid-tolateJulyisdesirable,theexactharvestingdateoftheprairiecanalsobevariableinordertomaintainprairiediversity.TheprairieshouldnotbeharvestedafterearlyAugust,however,inordertoallowtheplantstoproducesufficientcarbohydratestoragereservesforthewinter.

Fertilization,specificallynitrogenfertilization,canbeusedtoincreasetheproductivityoftheprairieandincreasethenutrientconcentrationsintheplanttissues;althoughannualfertilizationisnotnecessaryinmanagingprairiesforgrazingorhaying.Forgrazinginparticular,manyofthenutrients,includingmostofthephosphorusandpotassiumandsomeofthenitrogenthattheanimalsremove,arerecycledbacktotheprairiethroughtheanimals’urineandmanure.Annualfertilizationmaybestrate-gicallyused,however,forspecificorshort-termobjectiveswithfewlong-term,adverseeffectsontheprairie.Highratesoffertilizationoveralongperiodoftimemayleadtoadeclineinlegumeandforbconcentrationsbecausethegrassesarelikelytooutcompetethelegumesandforbswhennutrientavailabilityishigh.

Income Price ($/acre)

Yearlingsteer

1lbdailyweightgain/calf(for150days@$0.70–1.00/lb) $662–945

2lbdailyweightgain/calf(for150days@$0.70–1.00/lb) $809–1155

Economics - Gain (Livestock Grazing) For haying estimates see page 19.

17

Using Prairies to Produce Biomass FeedstocksWhat Is It?Feedstockisageneraltermthatdescribesarawmaterialusedtocreateaproduct.Inthiscase,thefeedstockisplantbiomass.Plants,includingprairieplants,arecomposedprimarilyofenergy-densestructuralcompoundsthatarenotreadilydigestiblebyanimals,includinghumans,butcanbeusedtoproduceenergyifbrokendowncorrectly.Thesecompoundsarecellulose,hemicelluloses,andligninandgenerallyaccountformorethan75%ofprairieplantbiomass.Prairiebiomasscanbeusedasafeedstockforeitherdirectcombustionorconversionintoabiofuel.

Prairiebiomasscanbeburnedbydirectcombustionforheatand/orelectricitygeneration.Oneproposedmethodofproducingelectricityfromprairiebiomassistoburnthebiomasswithcoal(calledco-firing)inexistingcoalpowerplants.Co-firingswitchgrass,awarm-seasonprairiegrass,withcoalwasdemonstratedatapreviouslyallcoal-firedpowerplantinCharitonValley,Iowain2006.Forsmallerscaleheatgeneration,prairiebiomasscanalsobepelletizedandusedforhomeheatinginstovessimilartowood-andcorn-pelletstoves.

Aproposedfutureuseofprairiebiomassisforconversionintobiofuels.Biofuelisageneraltermusedtodescribeallfuelsproducedfromrecentlylivingplantmaterial.Differenttypesofbiofuelscanbeproducedasliquidtransportationfuelssuchascorn-grainethanol,biodiesel,cellulosicethanol,synthesisgas,andbio-oil.Approximately95%ofthebiofuelproducedintheUnitedStatesin2008wascorn-grainethanol,whichisproducedwhenmicrobesfermentthestarchcontainedincornkernelsintoethanol.TheremainderofthebiofuelproducedintheUnitedStatesin2008wasbiodiesel,whichisproducedfromoils,primarilysoybeanoilintheUnitedStates.

CellulosicethanolisnotbeingproducedonacommercialscaleintheUnitedStatesyet,butinpassingtheEnergyIndependenceandSecurityActof2007,theU.S.Congressmandatedtheproductionof16billiongallonsofcellulosicethanolby2022.Cellulosicethanolissimilartocorn-basedethanolinthatplantmaterialisultimatelyconvertedintoliquidfuel.Cellulose,however,ishardertobreakdownthanstarch

Adollarfordollargovernmentsubsidymatchingprogramhasbeenproposedforfeedstockpricesupto$45/ton(Harte2008).

Expenses Price ($/acre)

LandrentLandcurrentlyinrowcrops $147–2011

Landcurrentlyproducinggrasshay $60–1381

FertilizationNitrogen(@$0.68/lbfrom0–150lbN/acre) $0–1022

Phosphate(@$0.90/lbfrom0–50lbphosphate/acre) $0–452

Potash(@$0.72/lbfrom0–130lbpotash/acre) $0–942

Application $2–183

HarvestcostsMow/conditioning $8–173

Raking $2–103

Baling4 $59–1393

Removingfromthefield(@$3.00/bale) $18–453

Economics - Costs

1Edwardsetal.2009a2DuffyandSmith20093Edwardsetal.2009b4Assuminglargesquarebales@950lbs/bale;@$9.40/balefrom3–7ton/acre

18

What Would a Bioenergy Feedstock Producing Prairie Look Like?Threeinterrelatedcharacteristicsofprairiesmanagedforbiomassfeedstockproductionarehighwarm-seasongrassdominance,highproductivity,andlownutrientconcentrationsinharvestedbiomass.Biomassusedfordirectcombustionortoproducebiofuelsshouldbeasdryaspossiblebecauseenergyisusedtotransportandremovethewaterfromthebiomass,andwetbiomassissusceptibletodecomposition.Inprairiesystemsinwhichthegoalistoproducelargeamountsofdrybiomass,asingleharvestaftertheplantshavesenescedisideal.Warm-seasonprairiegrasses,suchasswitchgrass,Indiangrass,andbigbluestem,arethemostproductivegroupofplantsinthistypeofsystem.Thereforeaseedingmixthatcontainsmostlywarm-seasongrasses(morethan75%)willhelpestablishthedesiredprairiecomposition.Usingplantsthatcontainrelativelylowtissuenutri-entconcentrationsintheharvestedbiomassisbeneficialbecausenutrientsintheharvestedbiomassarewasteproductswhenthebiomassisbeingusedtoproduceenergy,andkeepingtheplantnutrientsinthefieldreducesfertilizerrequirements.Prairieplantstranslocatenitrogenfromabovegroundbiomasstotherootsandleachphosphorusandpotassiumintothesoilviarainfallattheendofthegrowingseason,whichmakestheharvestedbiomassrelativelynutrientpoorandthenutrientsavailablefortheplantstouseinsubsequentgrowingseasons(Samsonetal.2005).

Occasionalfertilizationmaybedesirableinprairiesgrownforbiomassproductionbecausenutrientswillberemovedfromtheprairiewitheachharvest.Fertilization,particularlynitrogenfertilization,willalsoincreasetheproductivityoftheprairie,butitcandecreasethespeciesdiversityoftheprairie.Thereisgenerallyalinearincreaseinharvestablebiomassofwarm-seasonprairiegrasseswithincreasingnitrogenfertilizationuptoapproximately100lbsN/acre(Heggenstalleretal.2009).Thecompositionoftheprairiewillaffecttheamountofnutrientsharvestedeachyear.Forexample,cool-seasongrassescancontaintwiceasmuchnitrogenintheharvestedbiomassaswarm-seasongrasses.

duetoitschemicalstructureandtherelativelysmallnumberofmicroorganismsthatcanattackanddigestit.Otherbiofuelsthataremoresimilartogasolineordieselcanbeproducedfromsynthesisgasorbio-oil,whichareproducedwhenlignin,cellulose,andhemicellulosesinplantmaterialarecombustedathightemperatures.Synthesisgasandbio-oilarealsonotyetproducedonacommercialscale,thoughsimilartechnologiesforconvertingcoaltoliquidfuelshavebeenusedinsomecountriesfordecades.

Income Price ($/acre)

Biomass

Prairieproducing3ton/acre(@$15–45/ton) $45–135

Prairieproducing7ton/acre(@$15–45/ton) $105–315

Economics - Gain

19

Using Prairies to Sequester Carbon What Is It?Carbonsequestrationisremovingcarbonfromtheatmosphere–usuallyascarbondioxide(CO2)–andstoringitforlongperiodsoftime.TheCO2canberemovedfromtheatmospherebyplantsandanimalsandstoredbelowgroundorinwater.Forexample,plantsremoveCO2fromtheatmosphereinordertoperformphotosyn-thesis(theCO2isconvertedintosugars).Someofthesugarsareusedbytheplantduringmetabolism,butsomeofthesugarsareusedtoproduceroots.Whentherootsdie,microbesdecomposesomeofthedeadrootsandreleasethecarbonasCO2again,butsomeofthecarbonisnotdecomposedandremainsbelowgroundfortenstohundredsofyears.

CarbonsequestrationisofgreatinterestbecauseatmosphericCO2concentrationsareincreasingandarecontributingtoglobalclimatechange(inadditiontoothergreenhousegassessuchasmethaneandnitrousoxide).Governmentsaroundtheworldhaveorarebeginningtoimplementpoliciestoreducegreenhousegasemissionsandincreasetheamountofcarbonsequestered.IntheEuropeanUnionthereisamandatorycap-and-tradegreenhousegastradingsysteminwhichcom-paniesthatemitgreenhousegassesaregivenamaximumlevelofgreenhousegasemissions.Ifthecompaniesemitmoregreenhousegassesthantheyareallowedtoemit,theymusteitherinvestintechnologiestoreducetheiremissionorbuyemissioncreditsfromanorganizationorcompanythatiseithersequesteringcarbonoremittinggreenhousegassesbelowtheirmaximumlevel.TheUnitedStateshasavoluntarycap-and-tradesystem,butlegislationiscurrentlybeingproposedthatwouldmakeparticipationinthecap-and-trademarketmandatory.

Expenses Price ($/acre)

LandrentLandcurrentlyinrowcrops $147–2011

Landcurrentlyproducinggrasshay $60–1381Landcurrentlyinpasture $35–771

Fertilization $0–1022

Nitrogen(@$0.68/lbfrom0–100lbN/acre) $0–682

Application $2–183

Wetlandscansequesterlargeamountsofcarbon.Deadplants(fallenabovegroundpartsandroots)decomposeslowlyinwetlandsbecausewetlandsareoftenanoxic(withoutoxygen)anddecom-positionisveryslowwhenoxygenisabsent.Ifafarmfieldwasconvertedtoawetland,theamountofcarbonstoredinthewetlandwouldincrease–thewetlandwouldbesequesteringcarbon.Thecarbonthatisbeingseques-teredcanthenbesoldtoacompanythatisemittingmoregreenhousegassesthenitisallowedtoemit.

An Example – Carbon Credits for Wetlands

1Edwardsetal.2009a2DuffyandSmith20093Edwardsetal.2009b

Economics - Costs

20

Economics - Gain

What Would a Carbon Sequestering Prairie Look Like?Notallprairiessequestercarbon,butmostofthemdo.Thedeep,organic-matterrichtopsoilsthatareproducedunderprairiesaretheresultofthousandsofyearsofcarbonsequestration.Atsomepoint,however,theamountofCO2releasedfromthesoilthroughdecompositionisequaltotheamountofnewrootsaddedtothesoil.Manyoftheremnantprairies(prairiesthathaveneverbeenplowed)havereachedthisstateofequilibrium,butremnantprairiesmakeuplessthan0.01%oftheprairiesinthetallgrassprairieregion,sothereisgreatpotentialforcarbonsequestrationundermostprairies.Soilthatwasproducedunderprairiesbuthasbeenconvertedtorow-cropagriculturemaycontainonly10%to70%ofthecarbonstoredbelowgroundcomparedwithsoilthathascontinuouslygrownprairie.Reconstructingprairiesontothesesoilscanresultinsignificantcarbonsequestrationfordecades.Ratesofcarbonsequestrationvarywidelyunderdifferentprairies,butaveragecarbonsequestrationratesareapproximately1ton/acre•year(Piñeiroetal.2009).

Thecompositionoftheprairiealsoaffectstheamountofcarbonthatissequesteredbelowground.Prairiesthatproduceahighyieldabovegroundoftenproducemorerootsthanloweryieldingprairies,andtheamountofrootsproducedisthedrivingfactorindeterminingtheamountofcarbonthatisavailabletopotentiallybeseques-tered.Prairiegrasses,particularlywarm-seasonprairiegrasses,producemorerootsthanmostprairieforbs.Thereforeprairiesdominatedbywarm-seasongrasseshavethepotentialtosequestermorecarbonthanthosedominatedbyforbs.Furthermore,therootsofwarm-seasongrassescontainfewernutrients(especiallynitrogen)thancool-seasongrassesorforbs,makingthemdecomposemoreslowlyandremaininthesoillonger.

Fertilizingprairieswithnitrogenincreasesabovegroundbiomassproduction,butwhetherfertilizationincreasesrootproductioncomparedtounfertilizedprairiesismorevariable.Furthermore,nitrogenfertilizationleadstohighernitrogenconcentra-tionsintheroots,whichmayincreasethedecompositionrateoftheroots.Althoughmoreresearchisneeded,itdoesnotappearthatfertilizingprairieswithnitrogenisaneffectivemeansofincreasingtheamountofcarbonsequesteredbyprairies.

Income Price ($/acre)

Carboncredits(@0.93tonCO2/acre) $2–281

1Edwardsetal.2009a2DuffyandSmith20093Edwardsetal.2009b

1CO2sequestrationratesfromPiñeiroetal.(2009);pricesfromCCX(2009)andNordhaus(2008)

21

Linedrawingofwarm-seasongrass,cool-seasongrass,legume,andforbrootsto8ftdepthbyJ.E.Weaver.

ConclusionsThesoilformedbytallgrassprairiesisamongthemostagriculturallyproductivesoilintheworld.Becauseofitshighinherentproductivitynearlyallofthetallgrassprairieshavebeenplowedunderandconvertedintocropland.Yetre-incorporatingprairiesbackintoland-scapesdominatedbyrow-cropagriculturecanprovidebothshort-andlong-termbenefits.

Prairiesprovidenumerousecosystemservicesthatcurrentlydonotprovidedirecteco-nomicbenefitstofarmersandlandowners.Someoftheecosystemservicesprovidedbyprairiesthatwerediscussedpreviouslyare:

• reductionsinsoilerosion• reductionsinnutrientpollution• enhancementofbeneficialinsects• enhancementofwildlifeandbirdhabitat• stabilizationofthehydrologyofwatersheds

Therearesomeproductsandservicesthatprairiesprovide,however,thatarelikelytohavedirecteconomicvalueinthenearfuturesuchas:

• providingfoodforlivestock• producingbiomassforconversionintobiofuelsorfordirectcombustion• sequesteringcarbon

Incorporatingprairiesintomultifunctionallandscapesisonemethodofpotentiallygainingincomefromtheprairieswhilereceivingthenumerous“free”ecosystemservicesthattheprairiesprovide.

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What Other Resources Are Available to Me?Prairie Restoration Handbooks

• The Tallgrass Prairie Center Guide to Prairie Restoration in the Upper Midwest(2010 UniversityofIowaPress)isoneofthelatestresources(342pages)fromtheTallgrass PrairieCenterlocatedattheUniversityofNorthernIowa.DarylSmith,DaveWilliams, GregHouseal,andKirkHendersonsharemorethan100yearsofexperienceinprairie restoration,coveringeverythingfromplanningtoimplementingtomanagingaprairie. Theyalsoincludechaptersonnativeseedproductionandrestoringprairiesinpublic spacesandalongroadsides.

• The Tallgrass Restoration Handbook for Prairies, Savannas, and Woodlandseditedby StephenPackardandCorneliaF.Mutel.Therearetwoeditionsofthisbookboth publishedbyFirstIslandPress;thefirsteditionwaspublishedin1997,thesecond editionwaspublishedin2005.Thisisacomprehensivebook(464pages)onprairie, savanna,andwoodlandrestorations.Itprovidesboththeoreticalandpracticalper spectivesonrestorations.

• A Practical Guide to Prairie ReconstructionbyCarlKurtzwaspublishedin2001bytheUniversityofIowaPress.Thisisamuchshorterbook(57pages),andfocusesonthepreparationandmanagementneededtorestoreprairies.

Plant Identification Books (for both prairie plants and weeds)• Tallgrass Prairie Wildflowers: A Field GuidebyDougLaddwithphotosbyFrank

Oberlewaspublishedin1995byFalconPublishing,Inc.Thisprairieplantidentifica-tionbookcontainscolorphotosof295specieswithafullpagedescriptionofeachspecies.

• Wildflowers: Northeastern/North-central North AmericabyRogerToryPetersonandMargaretMcKennywithillustrationsbyRogerToryPeterson.ThisbookispartofthePetersonFieldGuideSeriesandispublishedbytheHoughtonMifflinCompany.Themostrecentversionisfrom1996.Thisbookcontainsmorethan1,000specieswithsomecolorphotosandmanylinedrawings.

• Weeds of the NortheastbyRichardH.Uva,JosephC.Neal,andJosephM.DiTomasowaspublishedin1997byCornellUniversityPress.AlthoughthefocusofthisbookisweedsintheNortheasternU.S.,manyofthe299weedspeciesde-scribedinthisbookarecommoninthemidwesternU.S.andinprairierestorations.

• Wetland Plants and Plant Communities of Minnesota and WisconsinbySteveD.EggersandDonaldM.Reedwasmostrecentlypublishedin1997bytheU.S.ArmyCorpsofEngineersintheSt.PaulDistrict.Thisbookhascolorphotosandlinedraw-ingsof144wetlandplantspeciesthatarecommontomidwesternwetlands.

Useful Websites for Prairie Restorations• TheIowaNaturalResourceConservationService(NRCS)hasanonline“NativeGrass

SeedingCalculator”thatallowsuserstodesignprairieseedingmixes.Itassistsinselectingappropriatespeciesforthesitecharacteristicsandprovidesseedingcostestimates.Thecalculatorisavailableatthebottomofthe“IowaNRCSTechnicalResources”webpage:http://www.ia.nrcs.usda.gov/technical/

• TheUnitedStateDepartmentofAgriculture(USDA)NaturalResourcesConservationService(NRCS)maintainsthe“PLANTSDatabase”whichprovidesphotographsanddistributionmapsofnearlyalloftheplantsintheU.S.Thedatabaseisavailableat:http://plants.usda.gov/

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ReferencesBrye, K. R., J. M. Norman, L. G. Bundy, and S. T. Gower (2000) Water-budget evaluation of prairie and maize ecosystems. Soil Science Society of America Journal 64:715-724

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Duffy, M. (2007) Estimated costs for production, storage and transportation of switchgrass. PM 2042. Iowa State University Extension, Ames, IA

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Edwards, W., D. Smith, A. Johanns, and J. Ahrendsen (2009a) Cash rental rates for Iowa 2009 survey. Ag Deci-sion Maker. File C2-10. Iowa State University Extension, Ames, IA

Edwards, W., D. Smith, and A. Johanns (2009b) 2009 Iowa farm custom rate survey. Ag Decision Maker. File A3-10. Iowa State University Extension, Ames, IA

Ellis, S., W. Edwards, J. Lawrence, and A. Johanns (2009) Livestock enterprise budgets for Iowa – 2009. Ag Decision Maker. File B1-21. Iowa State University Extension, Ames, IA

Harte, P. (2008) Biomass crop assistance program fact sheet. Available: http://www.sustainableagriculture.net/site/PageServer?pagename=Committees_Energy_Bio-mass_Crop_Assistance_Program [10 December 2009]

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Helmers, M., H. Asbjornsen, N. Grudens-Schuck, M. Leibman, M. O’Neal, L. Schulte, J. Tyndall, M. Harris, R. Cruse, P. Drobney, R. Kolka, M. Tomer, and C. Cambardella (unpublished) Learning and teaching with experimental watersheds: Evaluation of ecosystem services in mixed annual-perennial agroecosystems.

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Losey, J. E. and M. Vaughan (2006) The economic value of ecological services provided by insects. BioScience 56:311-323

Mitsch, W. J. and J. G. Gosselink (2000) Wetlands. 3rd edition. John Wiley and Sons, Inc., New York, NY

Nordhaus, W. (2008) A question of balance: Weighing the options on global warming policies. Yale University Press, New Haven, CT

Piñeiro, G., E. G. Jobbágy, J. Baker, B. C. Murray, and R. B. Jackson (2009) Set-asides can be better climate investment than corn ethanol. Ecological Applications 19:277-282

Prairie Moon Nursery (2009) Prairie Moon Nursery 2009 Catalog and Cultural Guide. Winona, MN

Samson, F. and F. Knopf (1994) Prairie conservation in North America. BioScience 44:418-421

Samson, R., S. Mani, R. Boddey, S. Skohansanj, D. Quesada, S. Urquiaga, V. Reis, and C. Ho Lem (2005) The potential of C4 perennial grasses for developing a global BIOHEAT industry. Critical Reviews in Plant Sciences 24:461-495

Schilling, K. E., M. K. Jha, Y. K. Zhang, P. W. Gassman, and C. F. Wolter (2008) Impact of land use and land cover change on the water balance of a large agricultural watershed: Historical effects and future directions. Water Resources Research. Doi: 10.1029/2007WR006644

Steuter, A. A. and L. Hidinger (1999) Comparative ecology of bison and cattle on mixed-grass prairie. Great Plains Research 9:239-342

U.S. Department of the Interior, Fish and Wildlife Service and U.S. Department of Commerce, U.S. Census Bureau (USFWS 2006) 2006 National survey of fishing, hunting, and wildlife-associated recreation. Available: http://www.census.gov/prod/2008pubs/fhw06-nat.pdf [3 June 2010]

Weaver, J. E. (1919) The Ecological Relations of Roots. Carnegie Institution of Washington, Washington, D.C.

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