Soil Classification, Identification, And Survey

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Soil Classification, Identification, And Survey
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Brown, R.B.
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SoilClassification,Identification,andSurvey1 TheInstituteofFoodandAgriculturalSciencesisanEqualOpportunity/AffirmativeActionEmployerauthorizedtoprovideresearch,educational informationandotherservicesonlytoindividualsandinstitutionsthatfunctionwithoutregardtorace,color,sex,ornationalorigin. FloridaCooperativeExtensionService/InstituteofFoodandAgriculturalSciences/UniversityofFlorida/JohnT.Woeste,DeanR.B.Brown2SOILDEFINEDSoilisanaturalbodycomposedofminerals, organicmatter,water,andairwhichcoverstheearth's surfaceandiscapableofsupportingplantgrowth.A typicalmineralsoilcontainsapproximately45% mineralmaterials,5%organicmatter,25%soilwater, and25%soilair(byvolume).Othersoils,ofcourse, mayvarywidelyfromtheseproportionsdependingon theirnatureandmodeofformation.Theorganic mattercontentofFloridasoils,forexample,ranges frompracticallyzeroinsomeofoursanddunesto almostl00%ofthesolidportionofsomesoilsinthe FloridaEverglades,with1to5%beingmore commonlyfoundinthesurfacelayersofmostsoils. Therearemanydifferentkindsofsoil.Eachand everysoilhasaprofilewhichconsistsofasuccession oflayersextendingdowntobedrock.Thenatureof thesoilprofilehasconsiderableinfluenceonthe growthofplants.Itinfluencesrootgrowth,moisture storage,andthesupplyofplantnutrients.The scientificstudyoftheprofileisfundamentaltothe understandingofasoil'snatureanddevelopment,for itcarrieswithinitselfarecordofitshistoryforthose whowoulddesiretoreadit.THESOILPROFILEAsoilprofileisaverticalsectionofthesoil extendingfromthesurfacedownthroughallofits horizons-"A,"orsurfacesoil;"E"and"B,"orsubsoil; and"C,"orunconsolidatedmaterials;abovethesolid bedrock,"R."Fordetailedinformationonhorizon designationsandsoilprofiledescriptions,seeSoil ScienceFactSheetSL-41,newSoilProfileand HorizonDesignations(l984)byM.E.CollinsandV. W.Carlisle.SOILTEXTURE"SoilTexture"isatermcommonlyusedto designatetheproportionatedistributionofthe differentsizedmineralparticlesinasoil.Itdoesnot includeorganicmatter.Thesemineralparticlesvary insizefromthoseeasilyseenwiththeunaidedeyeto thosebelowtherangeofahigh-poweredmicroscope. Accordingtotheirsize,thesemineralparticlesare groupedinto"separates."Asoilseparate,then,isa termusedtodesignateagroupingofthesemineral particles,suchgroupingtobebasedondefinite diameterlimitsusuallyexpressedinmillimeters(mm). Theclassificationofmineralsoilparticlesbythe U.S.D.A.isasshowninTable1. 1.ThisdocumentwaspublishedDecember1992asRF-AA001,FloridaCooperativeExtensionService.Formoreinformation,contactyour countyCooperativeExtensionServiceoffice. 2.ExtensionSoilScientist,CooperativeExtensionService,InstituteofFoodandAgriculturalSciences,UniversityofFlorida,Gainesville.

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SoilClassification,Identification,andSurvey Page2 Table1. ParticleSizeDistributionofTwoFloridaSoils NAMEOFSEPARATE DIAMETERLIMITS(inmm) NORFOLK LEON Al B2t Al B2h Verycoarsesand 2.00-1.00 2 1 0 1 Coarsesand 1.00-0.50 11 7 12 11 Mediumsand 0.50-0.25 18 12 40 33 Finesand 0.25-0.10 31 21 37 38 Veryfinesand 0.10-0.05 20 14 7 7 Silt 0.05-0.002 11 7 4 6 Clay lessthan0.002 7 38 0 4 100% 100% 100% 100% Sincethesevarioussizedparticleshavequite differentphysicalcharacteristics,thenatureof mineralsoilsisdeterminedtoaremarkabledegreeby theparticulargroupsthatarepresentinlarger amounts.Thus,asoilpossessinglargeamountsofclay hasquitedifferentphysicalpropertiesfromonemade upmostlyofsandsandsilts.Theanalyticalprocedure bywhichthepercentagesofthevarioussoilseparates areobtainediscalleda"mechanicalanalysis"ora "particlesizedetermination".Itshouldnowbe obviousthatanyandallmineralsoilsaremadeupof amixtureofsoilseparates,anditisonthebasisof theproportionofthesevariousseparatesthatthe texturalclassnamesofsoilsarerecognized.There aretwelvemajorclassesofsoils.Theircompositionis shownbyadiagramcalledthe"soiltexturaltriangle" (See"SoilTexture"--SoilScienceFactSheetSL-29.)SOILCLASSIFICATIONAND IDENTIFICATIONThesetwoterms,"classification"and "identification,"areoftenconfusedasbeing synonymous.Suchconfusionisperhapscausedby theircloserelationship. SoilClassificationisthelogicalgroupingof individualsoilsintocertaintaxonomicgroupsor categoriesaccordingtotheirsimilaritiestoone another.Suchagroupingwillincludemany individualsoilsthathavebeenrecognizedaswellas thosethathavenot. SoilIdentificationistherecognitionofan individualsoilaccordingtoitslocationandprofile characteristicsanditssubsequentplacementintoan alreadypredeterminedschemeofclassification.For example,anagriculturalworkercanidentifyasoilif sufficientinformationisknownaboutthatparticular soil. Both"classification"and"identification"ofsoils areimportant.Ofthetwo,however,soilidentification ismoreimportanttothefarmerandtothe agriculturalworkerthanisclassification.These peopleareprimarilyinterestedinbeingableto identifyaparticularsoil;bydoingsotheywillknow manyofthatsoil'scharacteristicsbyreferringto researchdatathathavebeencollectedonthatsame kindofsoilinotherlocalities.Suchidentificationwill alsogreatlyaidotheragriculturalscientistsin assessingtheproductivityofthatsoilandenabling themtomakegoodrecommendationsastoitsbest useandmanagement.SOILCLASSIFICATION(TAXONOMY)Soilshavebeenclassifiedinsomemanneror anotherforhundredsofyears.Theyhavebeen groupedaccordingtotheir(1)agronomicuse-good wheatsoil,poorcornsoil,etc.;(2)color-blacksoil, redsoil,etc,;(3)organicmattercontent-mineral soil,mucksoil,peatsoil,etc.;(4)texture-sand,sandy loam,loam,etc.;(5)moisturecondition-wetsoil,dry soil,etc,;andmanyothersoilcharacteristics.Eachof thesegroupingsservesaparticularpurpose;however, theyarenotveryscientificorup-to-dateaccordingto ourpresentknowledgeofsoilgenesis,morphology, andclassification.Infact,anewsystemofsoil classificationwasadoptedforuseintheUnitedStates onJanuary1,1965.Thedevelopmentofthis classificationbeganin1951andunderwentaseriesof

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SoilClassification,Identification,andSurvey Page3 sevenmajorrevisionsorapproximations.Gradually, aworkablesystemevolvedwhichcanbeusedto classifysoilsanywhereintheworld,anditishoped thatothercountrieswillalsoadoptanduseit. Basically,thisnewsystemtreatssoilsasindividual three-dimensionalentitieswhichcanbegrouped togetheraccordingtotheirsimilarphysical,chemical, andmineralogicalproperties.Categoriesofthis systemofclassificationandpropertiesofsoilusedto subdividedifferentgroupsofsoilswithineach categoryarediscussedinthefollowingparagraphs. Sincethisisanewsystemofsoilclassification,itis beingtestedcontinuouslyandslightmodifications maybeanticipated.CategoryI--OrdersThesedivisionsarebasedonbroaddifferencesin measurableandvisiblecharacteristicsofcertainkinds ofsoilhorizons.Thepresenceorabsenceofthese definitekindsoflayersindicateseitherthedominant activesoil-formingprocesswhichhascausedthatsoil todevelopasithas,orthelackofsuchdevelopment. Therearetensoilorders,manyofwhichfallinto definitegeographicrangeswhichareindicativeofthe importanceofclimate.Nineoftheseordersareused toclassifythemineralsoils,andoneorderincludesall oftheorganicsoils.Thesoilordersare:Entisols, Mollisols,Vertisols,Inceptisols,Aridisols,Spodosols, Alfisols,Ultisols,Oxisols,andHistosols.These ordersandtheiroriginsareshowninTable2. Table2. OriginsofSoilOrders Soil Order WordOrigin Entisol Entfrom"recent",anonsense syllable Vertisol L.verto,meaning"turn"or "invert" Inceptisol L.inceptum,meaning"beginning" Aridisol L.aridus,meaning"arid"or"dry" Mollisol L.mollis,meaning"soft" Spodosol Gk.spodos,meaning"woodash" Alfisol Alfifrom"pedalfer",anonsense syllable Ultisol L.ultimus,meaning"last"or "ultimate" Oxisol F.oxide,meaning"oxide" Histosol Gk.histos,meaning"tissue"CategoryII--SubordersEachoftheordersisdividedintoseveral suborders,eachofwhichinturnconsistsofsoils groupedtogetherwhichhavesomewhatsimilar developmentalcharacteristics.Thecharacteristicsused togroupsoilswithinthesamesuborderincludesuch propertiesasaccumulationofsolublematerialswithin theprofile,degreeofmottlingasreflectedby moistureconditions,presenceorabsenceofB horizons,andbroaddifferencesinmineralogyand chemistry.Ofcourse,thesamecriteriaarenotalways usedtoclassifysoilsintosuborderswithineachand everyorder.CategoryIII--GreatGroupsThesubordersarefurthersubdividedintogreat groupseachofwhichconsistsofsoilsgrouped togetherbasedlargelyonthepresenceorabsenceof certainkindsofimportanthorizonsthathavenot alreadybeenusedinthebroadercategoriesabove. Therelativethicknessofthesesoillayersisalso important.Othersoilpropertieswhichareoftenused includecolor,degreeofbasesaturation,tonguingof onesoilhorizonintoanother,irreversiblehardening, andthepresenceorabsenceofself-mulchingclays.CategoryIV--SubgroupsEachofthegreatgroupsisfurthersubdivided intoseveralsubgroups,withthetypicalorcentral conceptofagreatgroupmakinguponeofthe subgroups.Thissubgrouphasthesamenameasthe greatgroup,prefixedwiththeword"typic."Other subgroupshavesoilcharacteristicsthataresomewhat similartoboththoseofthecentralconceptandto thoseofanotherclassificationunit.Theyaresaidthen tobe"intergrades"andcarrythenamesofboth classificationunits,thelasttermindicatingthe dominatingpropertiesofthatparticularsoil.

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SoilClassification,Identification,andSurvey Page4CategoryV--FamiliesEachsubgroupisdividedagainintoseveral families,eachofwhichconsistsofsoilsgrouped togetheraccordingtotheirtexturalclasses, mineralogy,reaction(acidornonacid),andsoil temperature.Suchcharacteristicsgenerallyare indicativeofplantresponse,sothatsoilsgrouped togetherinthesamefamilyarethoughttoreactina similarmannertothesamecropsgrownunderthe samesystemofmanagement.CategoryVI--SeriesThedefinitionofsoilserieshasnotbeenchanged. Itstillconsistsofagroupofsoilssimilartoeach otherinalltheirprofilecharacteristicsexceptfor textureofthesurfacesoil.Severalcloselysimilarsoil series,ofcourse,areusuallygroupedtogetherinthe samefamily.SoilTypesandPhasesSoiltypesandsoilphasesarealsotermsusedin classifyingsoilsbutarenolongerrecognizedas categorieswithinthesystem.Asoiltypeconsistsof agroupofsoilssimilartooneanotherinalltheir profilecharacteristicsincludingthesurfacetexture.A soilphaseisusuallyusedtoexplainsomeminor variationwithinasoilseriesorsoiltypethatisnot significanttotheclassificationofthesoilinitsnatural landscapebutmaybeimportanttotheuseand managementofthesoil.Example:Lakelandfinesand, slopingphaseisasoilbelongingtotheLakelandfine sand;anditoccursonslopingtopographyratherthan onlevel,gentlysloping,orsteepslopes. Thenamesofthesuborders,greatgroups,and subordersautomaticallyidentifytheordertowhich theybelong,becauseeachtermincludesaportionof thesoilordername.Forexample,soilsofthe suborderAquodsarethewettersoils(L.aquafor "water")oftheSpodosolorderandincludetheletters "od"inbothorderandsubordernames.Likewise,the nameofthegreatgroupidentifiesthesuborderand orderofwhichitisapart.Haplaquodsareaquods withacertainkind(Gr.haplous,meaning"simple")of horizonwithintheprofile.Ifthesoilisconsideredto benearthemiddleconceptofallHaploquods,the subgroupdesignationisobtainedbyplacingtheterm "typic"infrontofthegreatgroupname.Thiscanbe illustratedinTable3. Thus,itcanbeseenthat,ifonlythesubgroupof Table3. SampleClassificationTerms Order Spodosol Suborder Aquod GreatGroup Haplaquod Subgroup TypicHaplaquod anysoilisknown,apersonfamiliarwiththis classificationsystemwouldalsoknowthegreatgroup, suborder,andordertowhichthatsoilbelonged.Ifa soilisnotconsideredtobetypicalofthecentral conceptofthegreatgroup,oneormoreotherterms areprefixedtothegreatgroupnametoexplainin whatmannerthesoilvariesfromthemodalconcept. Thiscanbeillustratedinadiagramwhichalsoshows certainfamilycriteriaandselectedsoilseries(See "SoilsofFlorida"sectionoflatestFloridaSoil IdentificationHandbookforsuchadiagram).LANDCLASSIFICATIONTheterms"land"and"soil"areoftenused interchangeably;however,theterm"land"hasamuch broadermeaning.Theterm"land"usuallyconnotes "use";forexample,forestland,cropland,wasteland, etc.Assuch,theselandsaremadeupofmany differentkindsofsoils.Thereare,ofcourse,many differentwaysinwhichwecanclassifyourlandsinto typesorclasses.Thekindofsoilsisoneofthe determiningfactorsinanylandtypeorclass.Ina landclassificationsystem,soilsaregroupedaccording totheirsuitabilityforcertainuses.Itisbasedon land-surfacefeaturesandsoilpropertiesthatcanbe evaluated.Suchanappraisalincludescertainbasic factorsrelatingtoboththetopsoilandsubsoil-soil type,slope,degreeoferosion,etc. Whileseveralsystemsareusedinclassifyingland, somearerathersimple,whileothersaremore technicalandscientific.SimpleClassificationofLandSimpleclassificationsareoftenusefultopeople whoarebuyingorsellingland;however,theyarenot asscientificasthepresent-daypracticalsystemswhich arediscussedbelow.

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SoilClassification,Identification,andSurvey Page5 Anexampleofasimpleclassificationoflandis illustratedbythewayacitrusfarmermightclassifyhis citrusland:(l)goodcitrusland,(2)faircitrusland, (3)poorcitrusland,(4)landunfitforcitrus.Another grower,mightclassifyhislandas:(l)goodcornland, (2)faircornland,and(3)poorcornland;oras(l) goodpastureland,(2)fairpastureland,and(3)poor pastureland.Asimilarclassificationissometimes madefortimberlandaswellasforlandusedinother ways. Banksandotherlendingagenciesoftenplacea monetaryclassificationonland,suchas:(l)$l,000per acreland,(2)$500peracreland,(3)$200peracre land,and(4)$50peracreland.PracticalClassificationsofLandSeveralpracticallandclassificationsystemsare presentlyinuse.Forexample,theagronomistmay classifylandontheabilityofsoilstogrowthe commonfieldcrops.Suchaclassificationmightbeas showninTable4. Theforestermayclassifylandinstillanotherway Table4. PracticalLandClassification ClassI Excellentland ClassII GoodLand ClassIII Fairland ClassIV Poorland ClassV Landunfitforfieldcrops -accordingtotherateoftreegrowth;usinggood, fair,poor,etc.,aslandclasses. Oneofthemostwidelyusedsystemsofland classificationisonethatwasdevelopedbytheSoil ConservationServiceasabasisforitswork throughoutthenation.Thissystemdividesalllands intoeightcapabilityclasses,eachbeingbasedonthe capabilityofthelandtoproduceandwithstand cultivationwithoutappreciableerosionorfertility losses(Table5).Eachclassinthissystem,aswellas othersystems,representsacombinationofsoil conditionssuchassoiltype,slopeofland,degreeof erosion,etc.Thelandcapabilityclassesareas follows:ClassILandComposedofsoilshavingfew,ifany,limitations thatrestricttheiruse.Suchlandisnearlyleveland doesnoterodereadily.Thetopsoilisdeepandeasy towork.Itholdswaterwell,butsomeareasmay needwatermanagement.Itisfairlywell-supplied withplantnutrients.Anyonewhoisfortunate enoughtohavesomeofthislandcanuseitsafelyin almostanywaythathechooses.Naturally,hewould wanttouseitforhishighestincomecropsand,of course,itshouldbewell-managedinorderto maintainbothagoodsupplyofplantnutrientsand goodphysicalconditions.ClassIILandComposedofsoilshavingsomelimitationsthat restrictthechoiceofcropsorrequiremoderate conservationpractices.Suchlandcanbecultivated safely,buthascertainphysicalconditionsthatmake itnotquiteasgoodasClassIland.Theslopemaybe juststeepenoughtomakewaterrunoffataspeed thatwillcarryawaysomesoil.SomeClassIIlandis naturallywetandrequiressomedrainage.Sinceclass IIlandhassomemoderateuselimitations,some specialtreatmentisrequiredwhichmayincludethe useofconservationpracticessuchascontouring, protectivecovercrops,simplewatermanagement, croprotations,ortheuseofmorefertilizers.ClassIIILandComposedofsoilshavingseverelimitationsthat reducethechoiceofcropsorrequirespecial conservationpracticesorboth.Suchlandcanbe cultivatedsafelyifsuchintensivetreatmentsas terracingandstripcroppingarefollowed.Usually, ClassIIIlandonflatareasneedssomekindofwater management.ThelimitationsofClassIIIlandmay bethesameingeneralasthoseofClassIIland,but arepresenttoagreaterdegree.ClassIVLandComposedofsoilsthatcanstillbeusedfor cultivation,thoughveryseverelimitationsonthe choiceofcropsandverycarefulmanagementmaybe required.Ordinarily,rowcropscannotbegrown safelyandclose-growingcropsareusedextensively. Choiceofcropsmaybelimitedbyerosionhazardsor excessmoisture.Oneormoreofthefollowing

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SoilClassification,Identification,andSurvey Page6 constitutethemostlimitingfactorsofthesesoils: steepslopes,severeerosion,shallowsoil,poor drainage,lowwater-holdingcapacity,orseverealkali and/orsalinity.ClassVLandComposedofsoilsgenerallynotsuitedto cultivationandlimitedintheirsafeusebyfactors otherthanerosionhazards.Examplesofsuch limitationsareasfollows:soilssubjecttofrequent streamoverflow,too-shortgrowingseasonforplants, stonyorrockysoils,andpondedareasnotfeasibleto drain.ClassVILandComposedofsoilshavingseverallimitationsthat restricttheiruselargelytopasture,range,woodland, orwildlife.Thelimitationsaresimilarto,butmore severethan,thoseforClassIVland.ClassVIILandComposedofsoilhavingveryseverelimitations whichrestricttheirusetograzing,woodland,or wildlife.ThelimitationsarethesameasforClassVI landexceptmoresevere.Evenpastureimprovement isimpractical.ClassVIIILandComposedofsoilsthatshouldnotbeusedforany kindofcommercialcropping.Thelimitationsareso difficulttoovercomethattheuseofthesesoilsshould berestrictedto"recreation,wildlife,watersupply,or aestheticpurposes".ExamplesofClassVIIIland includesandybeaches,rockoutcrops,andriver washes.SubclassesEachlandcapabilityclass(withtheexceptionof ClassI)isfurthersubdividedintosubclassesbased uponthedominantlimitationsforagriculturaluse. Theseareasfollows:erosion(e),wetness(w),root zonelimitations(s),andclimaticlimitations(c). Table5. Landclassesandsafeuses. USES LANDCLASS I II III IV V VI VII VIII Recreation&Wildlife X X X X X X X X Forestry XXXXXXX LimitedGrazing X X X X X X IntensiveGrazing XXXXX LimitedCultivation X X X X ModerateCultivation XXX Cultivation X X (NoCultivationBelowClassIV) VeryIntensiveCultivation X PrimeandUniqueFarmlandsAnotherapproachtolanddesignationthathas takenonincreasedimportanceinrecentyearsisthe identificationof"primeanduniquefarmlands"bythe U.S.SoilConservationService. Primefarmlandislandthathasthebest combinationofphysicalandchemicalcharacteristics forproducingfood,feed,forage,fiber,andoilseed crops,andisalsoavailablefortheseuses(thatis,itis notwetlandorbuilt-upurbanland).Ithasthesoil quality,growingseason,andmoisturesupplyneeded toproducesustainedhighcropyieldsundertreatment andmanagement.MostofFlorida'sprimefarmland

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SoilClassification,Identification,andSurvey Page7 islocatedinthenorthernandwesternpartsofthe state. Uniquefarmlandislandotherthanprime farmlandthatisusedforproductionofspecific high-valuefoodandfibercrops.Ithasthespecial combinationofsoilquality,location,growingseason, andmoisturesupplyneededtoproducesustained highqualityand/orhighyieldsofaspecificcropwhen treatedandmanagedappropriately.Amongthe high-valuefoodcropsthat,whencombinedwithother favorablefactors,qualifylandsasuniquefarmlands are:citrus,avocado,mangos,papayas,strawberries, vegetables,andsugarcane.MostofFlorida'sunique farmlandislocatedinthecentralandsouthernparts ofthestate. Primeanduniquefarmlandshavebeenidentified, county-by-county,acrossFlorida.Forinformationon wheretheselandsarelocated,contacttheSoil ConservationService. Foradditionalinformationonfarmlandsin FloridaandtheU.S.,andontrendsintheuseof theselands,see: NotesinSoilScience,No.5,TheNational AgriculturalLandsStudy(April6,1981). NotesinSoilScience,No.7,Agricultural LandsinFlorida--SummaryoftheLegislative StaffReporttotheHouseCommitteeon AgricultureandGeneralLegislation(May14, 1981). FloridaAgriculturalLandUse--WhatDoWe Know?pp.28-45InProceedingsofFirst AgriculturalPolicyForumonPublicor PrivatePropertyRights.AvailablefromR. Clouser,FoodandResourceEconomics Dept. SoilScienceFactSheetS1-36,LandUse PlanningandFarmlandRetention(May, 1981). FarmlandNotes.NewsletterofNASDA ResearchFoundationFarmlandProject,1616 HSt.NW,Washington,D.C.20006. NotesinSoilScience,No.8,Identificationof ImportantFarmlandinFlorida(September 20,1982). Symposium:TheFutureofAgricultureLand inFlorida.SoilandCropScienceSocietyof FloridaProceedings,Vol.41,1982.Reprints availablefromIFASSoilScienceDept.SoilidentificationInsoilidentification,soilsarerecognizedas belongingtoacertainsoilseriesbytheirsimilarities inmost,ifnotall,ofthefollowingcriteria: 1)Numberofhorizons 2)Arrangementofhorizons 3)Thicknessofhorizons 4)Colorofhorizons 5)Textureofhorizons 6)Structureofhorizons 7)Chemicalcompositionofhorizons 8)Geologyofparentmaterial Iftwosoilsaresimilartooneanotherinallofthese characteristics,theymustbeplacedintothesame seriesandbegivenonlyoneseriesname.Iftwosoils differfromoneanotherintwoormoreofthese characteristics,theycannotbelongtothesameseries and,therefore,aretwodifferentkindsofsoils. Whenattemptingtoidentifyaparticularkindof soil,oneneedstoknowasmuchaspossibleabout thatparticularsoil,itsprofilecharacteristics,its generallocationwithinthestate,andtheproperties ofothersomewhatsimilarsoilsinthesamegeneral area.SoilregionsAsoilregionisaphysiographicdivisionbasedon originofthesoilmaterial.AllofFloridaisaportion ofabroadprovinceknownas"coastalplainsoils",and consistslargelyofsandsandclaysoverlyinglimestone atvariabledepths.Inplaces,thislimestoneoutcrops atthesurface;inothers,itisseveralhundredsoffeet below.

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SoilClassification,Identification,andSurvey Page8SoilareasAsoilareaisasmallergeographicdivisionthan asoilregion.ThestateofFloridahasseveralsuch divisionsbasedonlocation,topography,native vegetation,andthephysicalandchemicalnatureof thesoils(SeeSectionI-2,SoilConservation).Each soilareaisuniqueinthatitcontainsacertainkindor groupofsomewhatrelatedsoils.Asanexample,soils ofthenorthernportionofwestFloridatendtobe fine-textured,withclaycontentsthatareconsiderably higherthanthosemostofotherareas.Also,soilsof thecentralridgesectionarecomposedmostlyofthick depositsofsandswhicharewelltoexcessivelydrained andarequiteacidinreaction.SoilsoftheFlorida Evergladeshavelargeamountsoforganicmaterials andareclassifiedaspeatsandmucks.SOILSURVEYModernsoilsurveysareunderwayatarapidpace inFlorida.Statusofmappingandpublicationis showninTable6. ForcopiesofSoilSurveyReportsorforrelated informationonsoilclassificationandsurveyina county,contacttheSoilConservationService. Additionalinformationontypesofsoilsurveys andusesthatcanbemadeofthemisavailableinSoil ScienceFactSheetS1-11,TheNatureandUseofa SoilSurvey(1977)byR.E.Caldwell,andin"Guide tothePracticalUseofSoilSurveys,"published cooperativelyin1984bytheSCSandIFAS. Seealsothe1982generalizedSoilMapof Florida,byCaldwellandJohnson,availablefromthe SCSorfromtheSoilScienceDept.,andthe1981 AtlasofFlorida,editedbyE.A.Fernald,Fla.State Univ.Foundation,Inc.,Tallahassee. Table6. StatusofmodernsoilsurveysasofSeptember,1988. COUNTY INPROGRESS COMPLETED PUBLISHED Alachua ----X Baker --X --Bay ----X Bradford ----X Brevard ----X Broward ----X (partial) Calhoun --X --Charlotte ----X Citrus ----X Clay ----X Collier --X --Columbia ----X Dade --X --DeSoto ----X Dixie X ----Duval ----X Escambia ----X Flagler --X ---

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SoilClassification,Identification,andSurvey Page9 COUNTY INPROGRESS COMPLETED PUBLISHED Franklin --X --Gadsden ----X Gilchrist --X --Glades --X --Gulf --X --Hamilton --X --Hardee ----X Hendry ----X Hernando ----X Highlands ----X Hillsborough ----X Holmes ----X IndianRiver ----X Jackson ----X Jefferson ----X Lafayette X ----Lake ----X Lee ----X Leon ----X Levy --X --Liberty X ----Madison ----X Manatee ----X Marion ----X Martin ----X Monroe --X --Nassau ----X Okaloosa --X --Okeechobee ----X Orange ----X Osceola ----X PalmBeach ----X Pasco ----X Pinellas ----X Polk ----X Putnam ----X St.Johns ----X St.Lucie ----X SantaRosa ----X

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SoilClassification,Identification,andSurvey Page10 COUNTY INPROGRESS COMPLETED PUBLISHED Sarasota ----X Seminole ----X Sumter ----X Suwannee ----X Taylor X ----Union ----X Volusia ----X Wakulla ----X Walton ----X Washington ----X