Soil Profile Description Manual - Virginia Department of ...

1 SoilProfileDescriptionManualCSES4124- :ksburg,Virginia24061-0404 PREFACET hismanualwasproducedbyrearrangingthecont entsofadraftofSoilSurveyManual(1991) ,NationalLeader,SoilClassification, (1991)hasbeenrearranged, , ..LANDSCAPEPOSITION(HILLSLOPES) ..SOILMOISTURE(INTERNALCLASSES) .ROCKFRAGMENTSDEFINEDROCKFRAGMENTSONTHES OILSURFACEBEDROCKOUTCROPS(ROCKINESS).. (SoilSurveyManual,1951)SoilConsistence(S oilSurveyManual,1991) (pH)BOUNDARIESOFHORIZONSANDLAYERS7677808 181889096 ..96 ..100 .. 12a . : observedexternalattributesofthepolypedon ,suchaslandformandcharacteristicsofslope ; inferredattributesofthepolypedon,suchaso riginofsoilparentmaterialandtheannualseq uenceofsoil-waterstates; observedinternalpropertiesofthepedon,suc hashorizonthickness,color,texture,struct ure,andconsistence; inferredgeneticattributesofthepedon,such ashorizondesignationsandparentmaterial; inferredsoildrainageclass; classificationofthepedoninthelowestfeasi blecategory; locationofthesiterelativetogeographicmar kersandintermsoflandscapeposition; plantcoveroruseofthesite; date,timeofday,andweatherconditions.

2 And ,describingtheirinternalproperties, , ,alongwithsomeadditionalinformation, , , ,Form1(6-24-91) (8-20-91) (orcrop) ,complexity, (degrees) (feet) (feet) (inches) (percent) (percent) :SOILDESCRIPTIONDateStop_SoiIWpe~~r~~aTe ch1 _Page2(8-20-91) ss'k'RF(%)pH(inches)MatrixMottlesDMWP orest'c'Micax' , , ,however, ,suchasthosemadewhensoilsaresampledforsp ecialstudiesorthoseofthetypicalpedonsofs oilseries, ; (1)bydefiningtheindividual'sownnotations or(2)byreferencingastandarddocument, ,5texture,mottling,structure,consistence ,roots,pores,additionalfeatures,reaction , (Thesecodesorsymbols,givenparentheticall yoridentifiedbySYMandmodifiedfromthe1951 SoilSurveyManual,areusedwithSoilDescript ionForm1tosavetimeinwritingsoilprofilede scriptions.) :IninchesorcentimetersfromthetopofA,orsu rfacemineralhorizon, :Horizonboundariesaredescribedastodistin ctnessandtopography.

3 Distinctness: abrupt(a) clear(c) gradual(g) diffuse(d) Topography: smooth(s) wavy(w) irregular(i) broken(b)Anabrupt, :Soilcolorsareindicatedbyusingtheappropr iateMunsellnotation,suchas5YR5 , , ,orcolors, , :6 Abundance: few(f) common(c) many(m) Size: fine(1) medium(2) coarse(3) Contrast: faint(f) distinct(d) prominent(p)Thusamedium-graysoilhorizonm ottledwithyellowandreddishbrowncouldbeno tedas:10YR5/1,c3d,10YR7/6and5YR4/4(or)10 YR5/1,c3d, OFMOTTLESANDCOARSEFRAGMENTS -I1%50;0 '.. I 20;0 3% 870; '.-I . ;030%,I.'" .:..-/5%I' .-. I ..,-,..20% -II ~.40% :.."..25%II50%Eachfourthofanyonesquareha sthesameamountofblack9 Texture:Thefollowingcodesfortexturemodif iersaresuggested: ,ifthetexturalclassisfinesandyloam(fsl)g ivenbelowandthehorizoncontains15to35perc entcobblesandgravel.

4 SYMT exturetermSYMT exturetermCOSC oarsesandFSLF inesandyloamSSandVFSLV eryfinesandyloamFSFinesandLLoamVFSV eryfinesandSILsiltloamLCOSL oamycoarsesandSISiltLSLoamysandSCLS andyclayloamLFSL oamyfinesandCLClayloamLVFSL oamyveryfinesandSICLS iltyclayloamCOSLC oarsesandyloamSCSandyclaySLSandyloamSICS iltyclayCClay10 Termsusedin-lieuoftextureSYMCECEMCINDDEF BFRAGGGYPHMICETermCoprogenousearthCement edCindersDiotomaceousearthFibricmaterial FragmentalmaterialGravelGypsiferousmater ialHemicmaterialIceorfrozensoilSYMINDMAR LMPTMUCKPEATSGSPUWBVARWBTermInduratedmar lMucky-peatMuckPeatSandandgravelSapricma terialUnweatheredbedrockVariableWeathere dbedrockStructure:Soilstructureisdescrib edbygrade,size,andshape. Grade: structureless(0) weak(1) moderate(2) strong(3) Size: veryfineorverythin(vf) fineorthin(f) medium(m) coarseorthick(c) verycoarseorverythick(vc)Usethinandthick forplatyinsteadoffineandcoarse.

5 Shape: platy(pI) prismatic(pr) columnar(cpr) blocky(bk) angularblocky(abk) subangularblocky(sbk) granular(gr) :SYMW etsoil:SYMloosedlnonstickywsosoftdssligh tlystickywssslightlyharddshstickywshardd hverystickywvsveryharddvhnonplasticwpoex tremelyharddehslightlyplasticwpsMoistsoi l:SYMplasticwploosemlveryplasticwvpveryf riablemvfrCementation: :IndicateeffervescencewithHclas: slight(e) strong(es) violent(ev)Specialfeatures:forexamplecon cretionsareindicateas: lime(conca) iron(conir) siliceous(consi) krotovina(wormholes)(k)12 STRUCTURESHAPEANDSIZECHARTSPLATYSTRUCTIJ RESVeryFineQeslIthan1mID.)Fine( )Medium( )Coarse( )VeryCoarse( )''''' '''-MUTTIYILLI..11710<>13 PRISMATICANDCOLUMNARSTRUcruRE~VeryFine( )III""'Medium(20-50mm.) (50-100mm.)14/0 ANGULARANDSUBANGULARBLOCKYSTRUCTURESVery Fine( )Fine(5 ) Medium( )Coarse( ) 15 SizesofGranularStructureVeryFine( )Fine( )Medium( )Coarse( )VeryCoarse( )16 : ee ee , ,thepatternsofsoiltemperatureandmoisture ,andthevariationsinsize,shape, , (samplingunit).

6 , , , , , ;consequently, , ,however,importantpropertiesofapedonaren otobservableinthesmallersample, ; , , Asoilhorizonisalayer,approximatelyparall eltothesurfaceofthesoil, ,ratherthanhorizon,isusedifalloftheprope rtiesarebelievedtobeinheritedfromthepare ntmaterialornojudgmentismadeastowhethert helayerisgenetic. Thesolum(plural,sola) ,forexample, (tobediscussed). ,asolumconsistsofA,E, ,orcontiguous, (SoilTaxonomy). (SoilTaxonomy) ,inageneralsense,inmanysoilsshouldbe18-- -------~~------------~--~-~~~-~--~~----- ---~ , , , ,forexample, Asequum(plural,sequa)isa , ,forexample,canformintheupperpartofanAlf isol, ,oneabovetheotherinthesamedeposit, , , , , ,too,thesoilsarenotconsideredbisequal; , , (Takenfrom:Schelling,J., , :169-193) ; (1965)formulatedanexcellentseriesofconce pts,laterelaboratedbyVanWambeke(1966), , : Individual:"thesmallestnaturalbodythatca nbedefinedasathingcompleteinitself".

7 Individualsthatareofinterestinclassifica tionaremembersofaclass. Class:anabstractfield, (singularormorecomplex), , ,onemustbeabletodistinguishindividualmem bers,andthesetogetherthenformtheclass. ,forinstance,acertainareaforwhichaclassi ficationisdrawnup,butitmayalsobeacertain abstraction, ,asoildevelopmentcycle. Particulateuniverse:Aparticulateuniverse containsdiscreteobjectsthatcanbecounted. , , , , ,mustbemeasurablewithinthemember-body. ,itisamember-bodywithinaparticulateunive rse. , : Classesareabstractconceptoftheclass, Inparticulateuniverses, ,exceptthearbitrarilyformedartificialind ividuals. Artificialindividualsaremember-bodiesofm inimumsize(determinedoperationally). soil bodiesAnumberofsoilbodies,significantfor ourproblem,willbeexaminedhere. ,becauseforthis, , Soillandscapeunit:Asoillandscapeunitisan objective,notarbitrary, , ,anarbitrarychoiceoftheboundarycriteriac anbemadebeforehand,butwithreferencetothe criterionchosen, , ,wemakeafurtherdistinctionbetweensoillan dscapebodies,polypedonsandlandscapebodie s.

8 Soillandscapebody:Asoillandscapebodyisas oillandscapeunitforwhichthemaximumlatera lrateofchangeofsoilcharacteristicsisused astheboundarycriterion. Polypedon:Apolypedonisasoillandscapeunit ,forwhichtheboundarycriteriaofsoilclassi ficationunits( ,soilseries) ,thepolypedonunderdifferentpedonsoccur,t heso-calledconsiderationcanberegardedasa "bodywithholes". Landscapebody:Alandscapebodyisalandscape unitforwhichthemaximumlateralrateofchang eoflandscapecharacteristicsisusedasthebo undarycriterion. ,Polypedons, ,notrealsoils,buttheyarerelatedtotheirre presentativesinnature--thepedon,thepolyp edon, (SoilSurveyStaff,1975) ~-----~ ,ifthegenetichorizonsarethin,intotheuppe rpartoftheunderlyingRelationshipofthepol ypedon, , ,apracticallowerlimitofthepedonisbedrock oradepthofabout2m, mprovidesagoodsampleofmajorsoilhorizons, , , mandallhorizonsarecontinuousandnearlyuni forminthickness,thepedonhasanareaofappro ximately1m2 Wherehorizonsorotherpropertiesareintermi ttentorcyclicoveranintervalof2to7m,thepe donincludesone-halfofthecycle(1to31/2m).

9 Ifhorizonsarecyclicoveranintervalgreater than7m, ,1to10m2, , ,asoilbody,homogeneousattheserieslevel, , ,ifever, ,regardlessoftheirlimitedsize, ,flexibleviewofthepedoninhisproposalofth epointpedonwhichcombinesthefixedposition ofapedonwithconsiderationofwhateverareai sneededtoidentifyandmeasuretheproperties underconsideration(Holmgren,1988).Thisco ncept,combinedwithcriteriaforthescaleofl ateralvariabilitytobeconsideredwithinone kindofsoil,couldestablishthepedonastheba sicunitofclassificationandeliminatethene edforthepolypedonihowever,theterm"polype don" , ,stoniness,degreeoferosion, ,thickness,andarrangementofhorizonsandth eirstructure,color,texture,reaction,cons istence,contentofcarbonatesandothersalts ,contentofhumus,contentofrockfragments, ,however, , ,polypedon,andsoilseriesaredefinedbyhuma nintellectforconvenienceinsamplingandcla ssifyingobjectswithinacontinuousuniverse , ,theyareartificialindividuals, , (definedabove) ,pedon, , ,possibly, , ,asoilprofile,shouldrecordthekindsoflaye rs,theirdepthandthickness, ,externalfeaturesareobservedthroughoutth eextentofthepolypedon.

10 , ,theexposedverticalfacesareexamined,usua llystartingatthetopandworkingdownward, , ,variationsofparticlesizefromtheoutsidet otheinsideofstructuralunits, ,railways,gravelpits,andothersoildisturb ancesprovideeasyaccessforstudyingsoils;o ldexposures,however, ,25thesoilstructureinsuchexcavationsismo repronouncedthanistypical;saltsmayaccumu lateneartheedgesofexposuresorberemovedby seepage; "I"I"II'I"I"I"I"I"I"I"I"I"\"rl"I"I"I"I"\ "\"I"l"I"IIII'II"I"I'T'I"I"I"I"I"I"I"I"I "I"I"j"I"I''1"1"1"1"11'1302' +21~.."216)Q1~J'12',+1' <IItl)6JO1"I'1260'+3' +2' ' ,'aUAD4-R-39293-1OC9 Z'9' 'ZOC9 Z'9V' ' ''S,Ct,0,II11tl0(ttl'It.~Jl+iII'Itl0(Sf; ZtittCiIZ"t9 IIIIItl(l(L"1II,d"Ldlll"I"I,d"I,,,,,I,,I ,,LII,,I,i1I,I,II"1"11,1"1,,1,,,,,1,,1,, 1,,1,,Ld1,1,,1\,1"1,,L,I"1"II,LII"I"II,I "IIIL,I"I,,I,, : Todeterminethelongitude, ,counttheticksfromthe0minutetothetickatt hefeatureandaddthisvaluetothelongitudeva lueprintedbeneaththeeastlineoflongitude. ))