An Introduction to SOILS OF PENNSYLVANIA

1 AnIntroductiontoSOILSOFPENNSYLVANIA .*.. Sn ..i~-:~z:/4.~ ~TeacherEducationSeriesVolume23,Number4 AGDEX512 Copiesof thisandotherspecialpublicationsoftheDepa rtmentofAgriculturalandExtensionEducatio nmaybeobtainedbywritingto:CollegeofAgric ulturalSciencesPublicationsDistributionC enterThePennsylvaniaStateUniversity112 AgriculturalAdministrationBuildingIUnive rsityPark, ,PA16802 ThePennsylvaniaStateUniversity,1982 ContentsINTRODUCTION3 SOILDEVELOPMENT4 TheGeologicCycle4 Weathering6 Vegetation8 ClimateandTime8 FORMATIONOFPENNSYLVANIASOILS10 BedrockandTopography10 ParentMaterial12 SOILPROPERTIES15 SoilTexture15 ActiveFractions17 SoilWater18 SoilpH19 CLASSIFYINGSOILS20 SoilSeries20 CountySoilSurveys20 GLOSSARY23 INTRODUCTIONA nunderstandingofsoils,theirdevelopment,p roperties,andusepotential,is ,whichfocusesonthesoilsofPennsylvania, recordofthegeologicalandclimatichistoryo ftheregionwhereit ,orrivers, haswithstoodandthekindofvegetationit weather,lifeforms,minerals areclearlyinterrelatedwhenwestudytheirre cordinthesoil.

2 He,too, , , ,it wasnotatrandomthatPennsylvania ,animportantindustryinPennsylvania,isdep endableherebecauseofplentifulwaterresour ces, sactivi-tiesdependentonthephysicallandsc ape, buildingiserected,wastematerialsde-posit ed,orthelandscapeotherwisedisturbed, ,toseehowtheyarerelatedto landscapefeaturesandtothesoil shistory,andto todayrepresentsonlyamomentinthevastageso fgeologictimeduringwhichcy-desoflandscap ebuildingandlandscapeerosionareslowly,bu tsurely, ,al-thoughit formsatdifferentratesinthethreekindsofro ck:igne-ous,sedimentaryandmetamorphic*. , ,beingloose,unconsolidatedmaterial,repre sentsthephaseinthegeologiccycleinwhichth eearth smineralmatteris interactingmostcloselywithlifeforms.* ~ ~. silt , , ,moltenrockstillsurfacesasvolcanoes, ,hardenedmoltenrock,knownasigneousrock, , , ,it is ,separatingsand,silt,andclay( ).

3 Thewater-borneandsorteddepositsaccu-mula te,arecompressed, ,substanceswhicharecompletelydissolvedin water,ultimatelyprecipitateoutassolids, ,siltbecomessiltstone,andsandbecomes-lak esurfacet~ ssurface, liesdeepwithintheearth,greatheatandpress urefurtherhardenandchangeit ,ittoowillslowlyweather,formsoilmaterial s,erodeaway,andeventuallyformrockagain, , , ,wind, , ,inthetransformationofrocktosoil,mineral sundergosomanychangesthatthesoilminerals ,althoughremainingrepresentativeoftheori ginalrockminerals, ,bythetimelimestonerockbecomessoil,it containsnocalcite(CaCO,), highlysoluble,it dissolvesinhumidclimates,leavingjustinso lubleim-purities, ,however,is , ,butinbogsandmarshesitis ,gravel,forexample, , ( ), ,whichhasthemostorganicmatterandis therootzone,is ,thesubsoilorBhorizon, horizonistheparentmaterial thelastlayer,theR staysinplaceforalongtime,vegetationbegin stogrowonthesurface,providingor-ganicmat terfromlitteranddeadroots, , , ,grassesgivetopsoilawell-aerated,crumbly structureandhighlevelsoforganicmatter( ).

4 ThesoilsoftheMidwestarehighlyproductive, , ,mattedorganicresidueoverthesurface,with arela-tivelylowleveloforganicmatterwithi nthesoil( ).Notonlydoesvegetationcontributetosoild evelopment, ,manyspeciesrequireparticularrangesofsoi lmoisture,texture,andacidity(pH).Forexam ple, acid, , , calcium,magne-sium,andpotassium arecarriedofftothegroundwater,soilfertil itydirr~ , ,makingit finer-textured(moreclayey) , spreadoveryourpalm,youwillnoticethatit ,orpeds, ,aswellasrainfall, ,withseasonalfluctuationsandannualfreezi ngandthawing,thesurfaceis pedologicage , (plow~ (surfacelitter) ,vegetation,climate, , shows, ,soilsarenotderivedfrommassiverock, , , schist,gneiss,andquartzite ,it is ,it , shale,sandstone,andlimestone ,sandstone, ,wrinkled, , ,thehardestandmostchemicallyresistantsed imentaryrock, ,theleastresistant, ,ofintermediateresistance,underliesthesl opes( ).)

5 Ccnca)0~00~I-0)00~0-oC(U00 0a)~0a)-Ca)0)12 ParentMaterialWhenbedrockbecomestheparen tmaterialforthesoilsde-velopingonit,it ,sandstonesoils,whichtendtobecoarse, ,suchastheHagerstownandDuffieldsoilsinLa ncasterCounty, withlargeadditionsoffertilizer, ,becauseshalecontainsPennsylvania ,andthenbackfillsthedepletedminewithcrus hedrock, gone,almostnothinggrowsontheminespoil,le avingabarrenwastelandwhicherodesandclogs upstreams( ). ,whichis oftenveryacid,infertile,andtoocoarseforp lantgrowth, , ,residualsoilis likelytoshalebewelldevelopedandproductiv e,asistheChestersoilofChesterCounty, ,whileresidualsoilsformedonsteepslopesar edeep, ,sandstonevastforestsrepresentthebestuse ofsteepmountainsidesbe-causetheyprovidea \,. ~,--N/1k:;~<i~ ,water,wind, ,aeolian,colluvial, ,fromboul-derstoclay,broughtinbytheicean dleftwhereit ,madeofmaterialcarriedandsortedbywaterfl owingfromthemeltingglacier, ,firmsubsoil, , ,orbess, ,foundinBucksCountyandlargelyusedforrowc rops,is , ,whichprovidesanoptimumsoiltexture,combi nedwiththeeffectsofgrowinggrassesovertim e, , s14 Becausecolluvialsoilshaveaproblematicfea turecalledfragipans, ,alsofoundinglacialtillsoils,aresubsoill ayersofexceptionallydensematerialwhichma ybeafewinchestoseveralfeetthick( ).

6 Theyarerelativelyimpermeabletowaterandim penetrabletoplantroots; ,alluvium sedimentcarriedbyflowingwater is ,whilegoodforfarming, ,periodicallythesiteofdevastatingfloods, , ,alsocalledsoiltex-ture,determineshowrea dilyairandwaterwillpassthrough,beheld, ,5 percentorganicmatter, ,halfoftheporespacesshouldbefilledwithwa ter, (seetheactivefraction,page17) ,onecantellapproximatelywhatpercentageof eachparticlesizemakesupagivensoil,andwhe reit belongsonthetexturaltriangle( ).Particleslargerthan2 ~-sizeparticles,referredtoasfineearth,ar elessthan2 mmindiameterandaredividedfurtherintosand ,silt, ,silt,andclayreferonlytosize,nottotheche micalmakeupoftheparticles, , ; ~grainswithplantrootcoatingsandgrains161 00908070 CLAY~ ~useit,locatetheappropriatepercentclayon theclayscale, ; SAND SAND-~intersectinthecompartmentwhichrepr esents00~-s~~ 50% ,acoarsesandis1,000timeslargerthanacoars eclay, , ,soilcomposedoftoomuchsandwillnotholdeno ughwateror~ < ,it ,sobesssoils(page13) , , consideredheavybecauseit ,watermay~ ,thesmallpores/collapseifanythingheavypr essesonthesurface, ~~tionsmashesthesoilaggregatesandclosest hechannelsSAND/OOSmm 2mm forairandwater, ,slippery,andmuddywhenwet, \tincompactedsoil, ~-~--- 17sandgrainclayparticleswithtightlyheldc oatingofwaterH+ , ( ).

7 Forexample, morestronglyattractedtothesitethantheion occupyingthatsite, ,orbecomeadsorbed,totheclay, calledtheexchangecapacityofthesoil( ). foundonhumus , ,butis ,forexample,is re-leasedintothesoil,claysadsorbundesira blesubstances, , ~$-~H+1~ (soilwater).j18 SoilWaterAfteraheavyrain, , ,whichisnotafreeliquid, , , poorandthesoilis saturatedforpartoftheyear(usuallyinsprin g),patchesofgrayandorangediscolorations, calledmottles, ,thepresenceofafragipan, oftenrelatedtolandscapeposition( ).Whereastheuplandandupperslopesareusual lywelldrained, , ,ormoreacidic, , ,45inchesofrainfallinPennsylvania, ,soilsrangefromacidintheeasttoneutralint hemidwesttoalkalineinthewesternstates( ).TheeffectofrainfallonsoilpHisagoodexam pleofhowsoil-formingfactorssuchasclimate ,time,parentmaterials,vege-tation, , ,vegetation,soilprofile, (100thmeridian)Pennsylvania10 rainfall20 rainfall45 rainfall(wheatbelt)(cornbelt)desertshort tallshrubsgrassesalkalinesoilspH>7neutra lsoilsacidsoilspH<720 CLASSIFYINGSOILSSoilSeriesSoilshavebeenc lassifiedintoorders,suborders,greatgroup s,subgroups, ,temperatureandwaterregimes,andspecialfe aturessuchasfragipans,aresomeofthecharac teristicsonwhichthesystemis ,suchasparentmaterial,texture,drainagech aracteristics,horizonse-quence, ( ,Duffield,Volusia,orConotton)andiscalled asoilseries( ).

8 , ,includingmaps,yieldpotentialsforeachsoi lse-ries,limitationsfordevelopment, ,yourrepresentativeinCongress, :AgronomyExtension,106 AgriculturalAdministrationBuilding,ThePe nnsylvaniaStateUniversity,UniversityPark , TheirExtent,Classification,Characteristi cs, )-C0)0-oC0Co2200U)a)~~)cnbfl~~U)ww,oW0U) 0~C0)a)CU)C0~4~-4~00 HHR~4-~0~~ROHR.~HO ~c~0IH,.~000 4~4t)I~OH -4WU)R1~OHIU)W~J~I(U~JInH>UURCl, ~00~-~U)~C~~1 TTir~F10U)U)H(U~HCio~-4c~bfltl~J0H( )OtICJICtIRd1)~<HR~0 4-4(U~Hw.~CL4-4 InIC(U0-ebflOO~H~-~oOlDC)(CO(C~tO4JH~d~- ~bC~ ~U)CCt~t(~.0I-III)(Ca)2HE IhullHI-) ~JI~jO~0)001~~a)2_IC( ,4aagdpI,4, ij iIjiJiaJifl ~.11 jII~uu~~ hi!.!iiriii1111111 IjijiijI33J3aa ~14141414l~l~I4141414aICe,433frfr 4mc,2w]~-u~pg 4U 4aUaiiVIA.~. ~ih~ 4 4~g 4 4 4 4 4 4 4 4 4U 4 frU 4 4EA~~~EOftmmmmammUUU Uq4 aPurl~g4, ,1wgoa ~aa 14jj a3,,iiII11kk~4iu?

9 UxuuuuxflPdhhurmnu;?x~uxx4;BflliflINIIIt P IUMMOBBMMdHI]GLOSSARY23activefraction componentofthesoilhavinganionexchangecap acity,specificallyclayandor-ganicmattera dsorb collectandadhererelativelylooselyona surfaceaeolian windbornealluvium river-bornedepositofrockandfineparticles bedrock solidrockmantleunderlyingsoilortransport edrockmaterialcalcareous soilorrockmaterialwithhighcalciumcarbona tecontentclay a) )soilcontainingmorethan45percentclay,les sthan40percentsilt,andlessthan45percents andcolluvium adepositofrockfragmentsandsoilmaterialac cumulatedatthebaseofsteepslopesasaresult ofgravitationalactionexchangecapacity interchangebetweenanioninsolutionandanot heriononthesurfaceofanysurface-activemat erialsuchasaclayororganiccolloidfragipan s naturalsubsurfacelayerswithhighbulkdensi tyrelativetothesoilabove,seeminglycement edwhendry,somewhatbrittlewhenmoist.

10 Lowinorganicmatter,mottled,slowlyorverys lowlypermeabletowaterandoftenshowingblea chedcracksformingpolygonsglacialtill unstratifiedglacialdriftdepositeddirectl ybytheiceandconsistingofclay,sand,gravel ,andbouldersintermingledinanyproportionh orizons(soilhorizons) layersofsoilorsoilmaterialapproximatelyp aralleltothesurface,occurringnaturally,a nddistinguishablefromadjacenthorizonsbyd ifferencesincolor,tex-ture,quantityoforg anicmatter, :0=thesurfacelit-ter,A=topsoil,rootzone, B=subsoil,containingmoreclayandlessorgan icmatterthanA,C=parentmaterial,andR=bedr ockigneousrook rockformedfromthecoolingandsolidificatio nofmoltenrock,andthathasnotbeenchangedap preciablysinceitsformationbess materialtransportedanddepositedbywindand consistingprimarilyofsilt-sizedparticles metamorphicrock rockderivedfrompre-existingrocksbutdiffe ringfromtheminphysical,chemical,andminer alogicalpropertiesasaresultofnaturalgeol ogicprocesses,principallyheatandpressure , ,sedimentary,oranotherformofmetamorphicr ockminespoil shatteredrockmaterialremovedtomakewayfor miningoperationsandreplacedatthesitewhen themineisabandoned24mottles spotsorblotchesofdifferentcolororshadeso fcolorinterspersedwiththedominantcoloror ganicmatter anyorganisms,aliveordead.