PU RPOSE This exercise is intended to relate the preceding exercise on soil profile descriptions to the areal expression of landscape segment differ­ences on soil maps. Making soil maps involves a great deal of work and requires considerable experience of soil scientists, but anyone can learn about soil maps in accord with the relative invest­ment of time and effort. This exercise can involve several half-days or full days in mapping the soils of the same study area in which the pits for the previous exercise were located. All the information on pages 1-40 of the textbook is used in making and evaluating soil maps.

PROCEDU RE View aerial photographs of the study area stereoscopically (Soil Survey Staff, 1962) and delineate (in pencil) the major land­forms (hills, valleys, plains, swamps, mountains, etc.). Locate on the aerial photos the pits from the preceding exercise. Then go into the field with spade and auger and investigate the variability of soils within each landscape segment. Observe vege­tation and other land-use patterns. Walk along transects and tabulate statistical data on the soils. For example, in several 100-meter transects (perpendicular to contour lines), take borings at 10-meter intervals to get a percentage estimate of soil variability. Identify areas different in soil color, texture, structure, consistence, pH, stoni­ness, depth to rock, relief, drainage, and so on. Do not attempt to show areas too small to plot con­veniently on the map at the scale designated. Use symbols for wet spots, eroded knobs, rock out­crops, gumbo or scabby spots, and so on. Make soil separations that are significant to use and management for present or intended use. Then ink the map and put symbols within each soil boun­dary for each soil map unit. Write soil map unit descriptions for each soil, slope, and other delinea­tion. Profile descriptions must be made from pits to represent the "modal" (central) concept of each soil. All the information should be organized into a soil survey report, including narrative, soil profile descriptions, map unit descriptions, and soil map of the area. In summary:

10

1. Delineate landform boundaries on air photo viewed stereoscopically.

Soil maps

2. Investigate soil variability within landforms by digging at regular intervals along transects.

3. Refine map legend and soil boundaries from soil profile descriptions and variability observations.

4. Make detailed soil map unit delineations with­in landforms by digging in the soils in accord with detail and scale of mapping.

5. Ink the map boundaries and symbols on air photos or base map.

6. Write soil map unit descriptions. 7. Integrate all the information into a soil survey

report for the area.

EXAMPLES Figure 2 is an example of a de­tailed soil map made on an aerial photographic base. Only about 300 acres can be mapped in a day of hard fieldwork in this complex soils landscape. The original scale of publication was 1 :20,000, so that areas of different soils as small as 1 hectare or several acres could be delineated. The soil legend for Tompkins County, for which Figure 2 is a part, is given in Table 6. The detailed legend for the detailed soil map identifies the specific soil name, texture, slope, erosion class, and depth to bedrock. Other soil characteristics are described in the text of the soil survey report (Neeley et aI., 1965). Figure 3 is a reproduction of the soil map without the air photo base, which is particularly valuable for coloring or shading with different patterns and for making interpretations about uses of the various areas.

The same principles of soil mapping, of course, can be applied at any scale to any base map. Figure 4 is the central portion of the soil map of New York State, with the geologic and Soil Taxonomy (Soil Survey Staff, 1975) legend and a "limitation legend" (Cline and Marshall, 1977). The origi nal scale of this map was 1 :750,000, and each general soil map unit contains a variety of different soils­but in a predictable pattern in the landscapes. The general legend indicates the dominant glacial materials in which the soils have formed, and the dominant soils and general Soil Taxonomy cate­gories. The limitation legend indicates that the primary problems are droughtiness, steep slopes, shallowness to bedrock, stoniness, and wetness.

G. W. Olson, Field Guide to Soils and the Environment Applications of Soil Surveys© Dowden & Culver, Inc. 1984

Figure 5 illustrates another general soil map, for part of Thailand. The alluvial plain (delta) in which Bangkok is located stands out in the south­west (lower left) part of the map, and the uplands can be identified from the legend in Table 7. Al­though the map in Figure 5 is general and at small scale, the soil and geomorphic differences shown on the map are very great and of extreme signifi­cance for national and regional planning. Figure 6 illustrates the situation in the alluvial plain north of Bangkok, where vast areas are flooded during the monsoon season. Figu re 7, in contrast, shows the soil condition typical of many of the uplands, where deforestation has recently taken place and where erosion is severe. Soil classification units in Table 7 can be roughly converted (updated) into Soil Taxonomy units accordingly to the following correlations (Soil Survey Staff, 1975):

Classification Units Soil Taxonomy (Moormann and Rojanasoonthon, 1972) (Soil Survey Staff, 1975)

Regosols Entisols Alluvial soils Inceptisols Peat and Muck soils Histosols Low-Humic Gley soils Alfisols Non-Calcic Brown soils Gray Podzolic soils Red-Yellow Podzolic soils Grumusols Rendzinas Brown Forest soils Red-Brown Earths Reddish-Brown Lateritic Reddish-Brown Latosols Red-Yellow Latosols

Alfisols Alfisols Ultisols Vertisols Mollisols I nceptisols Alfisols Oxisols Oxisols Oxisols

REFERENCES

Cline, M. G. and R. L. Marshall. 1977. Soils of New York landscapes. Information Bulletin 119, New York State College of Agriculture and Life Sciences, Cornell University, Ithaca, NY. 62 pages and map.

Moormann, F. R. and S. Rojanasoonthon. 1972. The soils of the Kingdom of Thailand. Report SSR-72A, Minis­try of Agriculture and Cooperatives, Dept. of Land Development, and Food and Agriculture Organization of the United Nations. 64 pages and maps.

Neeley, J. A., E. B. Giddings, and C. S. Pearson. 1965. Soil survey of Tompkins County, New York. U.s. Dept. of Agriculture, Soil Conservation Service, in cooperation with Cornell University Agricultural Experiment Sta­tion. U.s. Government Printing Office, Washington, DC. 241 pages and 38 soil map sheets.

Soil Survey Staff. 1962 (under revision). Soil survey man­ual. Agricultural Handbook 18, U.s. Dept. of Agricul­ture, U.S. Government Printing Office, Washington, DC. 503 pages.

Soil Survey Staff. 1975. Soil Taxonomy: A basic system of soil classification for making and interpreting soil sur­veys. Agriculture Handbook 436, U.S. Dept. of Agricul­ture, U.S. Government Printing Office, Washington, DC. 754 pages.

Soil Maps / 11

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GENERAL SOil MAP OF NEW YORK STATE

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FIGURE 4/Portion of the general soil map of New York State. Scale of original map 7,' 750,000 (Cline and Marshall, 7977).

14 / Field Guide to Soils and the Environment

FIGURE 5/General soil map of Thailand for area north-northeast of Bangkok. The Gulf of Thailand is in the lower left of the map, and the Laos border is at the top of the map to the north. Scale of original map 1: 1,250,000 (Moormann and Rojanasoonthon, 1972).

Soil Maps / 15

FIGURE 6/View of alluvial plain north of Bangkok. During the monsoon season most of the plain is flooded with one to several meters of water, up to the bottom of the house built on stilts. A common crop of the area is "floating rice, " which grows upward as the floodwaters rise, with the heads floating on the surface of the water. Often, the rice is harvested in boats.

FIGURE 7/Deforested and eroded hills northeast of Bangkok. Large areas have recently been cleared of forest in Thailand, and soil erosion is severe in many places. Soil maps could help a great deal to plan revegetation programs, and to manage watersheds so that environmental damage is minimized.

TABLE 6/Soil map unit legend for Tompkins County, New York.

SYMBO L

Ab A,8 A,C

8.8 8.e Ba C) 8.0 8.e BIIC3 8,0 80E 81f 8 . A

C. CdA CdC CdD CtA Cf8 CIS3 C0 8

0,8

£b8 EbB3 Ebe EbC3 EoA Em E,A

Fd8 Fm

Go

H. H< HdA HdC HdCK HdD

Hm8 Hme HmC3 H,E Ho' H,C H,D H, 8 HsC3 H sD3 H,8 HuB3 HuC3 H, D H.8 H,E

I,A ,,8

NAME

A ll u ~ l d l I ~nd

A, koo .t t In e Sandy loam '2 to 6 percent s lopes Arkpo rt f ,ne sandy 'oam , 6 t o 11 percent slopes

Bal h c ha n n e,y s ilt loarT', '2 to s lopes

Bath channe'y ~'It lo am, 5 to oercent slopes

Balh channery s d l loam, 5 1 0 15 percent slooe s, eroded Bath ch annery 5,11 loam, 15 to 2 5 pe rcent ~loDe5 B at h and Val o . ~ gravp lly S oi l loams, 5 to 15 percent s lopes B<lth anC Val o 's gra ve ll y ~l lt loam s, ~ to 15 perce'H Sl opes, erOded Bat h and Va lo,s grav(' lly ~ ,I ! l oams 15 to <'!:l PerC",n ! SlOpeS

Bath and Val o '~ 50 0l ~ 25 10 35 per( en l 51001'5 8al h, Va lo ,s a nd LanS ing SOliS , 15 to 60 Pf"cen! s lopes B rM e • • ile g rave lly ~ I" loam, 0 to 5 pe rc ('nt ~ l ope 5

Che nango gra el ,y loam, 0 to ~ oercent slopes

Ch en ango &'av(',,, loam, 5 t o 15 pe'cent slope s Chenani/O grHelly loam 15 to 25 perc>:"t ~IOD es

Conesus gra"elly 511 1 loam, 0 10 J p"'cent SiOPe~ Con esus &rav e l:" 501t l oam, 3 10 8 perc-ent slopes Conesus &ravelly 5 ' 11 l oam, 3 to 8 pf' rcent s lope s, erod ed

Chenango gr ave ! l" loam, l an, 0 to 8 pe rcent s lopes

Da ro en g.avelly sll l loam, 2 to 8 pe rCt' n t slopes

Eroe ch ann er.,. s ilt loam , 3 to 8 perct'n: ~ l ooe5

Ero e lhannery 5" t loam, 3 10 8 Pe rct'n t s lopps eroded E"e ch an nery s li t 'oam 8 (0 l !:l Ot'rcent s l o pe~

El iI' Ch J f1fH:, ry Silt lo am , 8 10 15 "t'rct'rll slopes, ('roded EI; l' r~ ChlPoewa, ~n d Ald en SO il s , 0 to 8 percen t s lopes Ee l Silt loam

F'edon sd l loam, 0 to 5 pe rcent ~ I opes

Ffe sh water mafsh

Genesee solt loam

Ha lSey s,l t loam

Halsey muck~ 5 01 1 :oam Howard gra ', elly loam , 0 to 5 percent slopp s

Howa, d iravell y lo"m, 5 to 15 Pt' rcen i Simple slopes Howard gra .. e lly ! o"m 5 10 I:' percent comple. slopes Howard i/fave,ly loam , 1510 25 pefcenl slopes

Honeo"e gravelly 5111 l oam, 2 to 8 percent slopes Ho neo"e gra .. ell " s.lt loam, 8 10 15 percent slopes Honeo~e IiiIra .e ll y s, ll loam, 8 to 15 percent s'opes , eroded Howa rd and Pa lmyra SOol $, 25 to 35 percenl slopes H oward and Pa lmy ra sods , 35 to 60 percent s lopes Howard Val o ,s g r ~velly l oams, 5 to 15 Ol'''ent slopes Howard Vd lo l s l/ ,a~<:,lIy l oam~ !5 10 25 perce flt s lope ~

Hudson Sil t y c lay \iam , 2 !O 6 percent s lopes

H udson s ll~ y c lay loam, 6 to 12 percent slopes, eroded Hudson s"ty ( l ay lo am, i2 to 20 percenl sl opp- s, erOded Hudson Cayuga 5 ' I l oam~, 2 t o 6 perC,"nl slopes

Hudson Ca"ul/J ~ ,,! loam s, 2 to 6 pefcent sloDe~, eroded Hud~on CJYUl/3 ~ llt loam s, 6 :0 12 percent eroded Hu dson C~yuia ~ . II l oam~ , 12 to 20 percent Hud ~o n anC Colian'e r s ,1I 10amS, 2 1 0 6 perc,"nl s looes Hudson ana Ou nk " k so. l s, 20 10 45 pefcent slopes

l loon ~ ,ll y c lay 10<lm, 0 !O 2 pe rcent slopes

Il ion ~dly cJay loam, 2 10 6 percenl ~ I opes

16 / Field Guide to Soils and the Environment

rhe !" st cap Ita l le t ter ,~ the ,n.t,a l o ne of ,I'1e 50 01 na m e A second cap ,ta l letter . A" B. C 0, E. 0' F shows th e s lope A fourt~ l ette r, (a p ,la t K In a

symbol shows tha t th e s looe IS como l e~ Some s~m bols

With out a s lope le tt e r are for nea r l ~ ;eve l SO,IS 0' IMHJ

types, but othe· s art' for so"s or 'and tyoes tha t have a cons Iderabl e .ange In s lope A flnai number. 3 In th e

symb ol shows that the so, 1 IS erOded

SYMBOL

K.8 KoA

L.8 LaB3 L.C LaC3 LbA Lb 8 LbB3

LbC LbC3 LmA Lm 8 LmB3

LoC LnC3 LoD lo E

lo' "8 uc l,

M.8 M.C MaC3 M o MID

Mo M o M,

N.8

D.A DcC ) D ,A 0 ,8 O' C

P.A P.C PaCK P.D Po. Ph8

00. OkA Ok8 R ... C3 00

T,A

Vb8 VbB3 Vbe IIbC3 VoA VoD

W, W,8

NAME

Kenda 'a sli t loam , 3 to 8 per l en! s lopes

Kend a,a and Lyon~ Silt loams , 0 to 3 pe rcen t slopes

{h an nery Sill loam, 2 to 8 perc!:'nt slo pes (l'1annpry stlt loam 3 to 8 pe' cent Slopes, eroden

Silt 'oam, 8 10 15 Pt" cent SIOOeS, eroded loam, 0 to 3 percenl s lopes

Lans,ng is'a vt' lI y sd t loam . 3 to 8 pelcent sloP('S Lan s,ng 8 ra~elly ., ,11 loam 3 10 8 pe T{ ("11 s lopes e' oded Lans"'g gra" .. lIy sol t loam 8 to 15 perc!:'n! s lopes LanS ing g'ave lly sol t l oam 8 to 15 ;Je rc!:'nt Slopt'S, e roded L im a sd t loam, 0 to 3 pereen! s loPt'S L ,m a sli t loam, 3 to 8 pere .. nl s lop .. ~ LIm a srlt loam 3 to 8 Pe rr en ! L(} ,d~lowr ch dnne ry Sd \ l o~m 5 to

Lo 'dSlOwn channe'y Silt 'Oam , 5 to i5 p ~r (.' nl s 'ope, Hoded Lcrostown Channe' y s,lt lOam, : 5 to 25 p~ .( .. rt ~ IOp~S

Lordstown (harn e r~ 5111 ,0Jm }5 to 35 pt'" en t SIODes LO'd,;wwn SO il S, 35 10 70 perc en t slopes

l o rdstow n, Tu l,e r, and Ov .d so .t ~, ; ha l'cw and .. e ry ,;na ll ow, 0 to is pe rrent ,IOPf" , lo ,d stown, Tulter, and Ov ,d ~O ol 5 . ~na low and very 5nal lOw, 1510 ,:, pe rl enl ,10PP$ lyons 5.1 1 loam

Mard,n cn ~n nt'ry ~ . I t loam, 2 to 8 peru:!n t ~ I opes

Mdrd ln cha n"e'y ~ tl t loam, 8 to 15 perce nt s l ope~

M~,d , n c ~,a n n e'y ,ti l loam 8 to 15 perce nt s looes, eroded Ma1t' land M~rd,n and Langlord s o , , ~ , 15 to )') oercl'nt ~loPI? S Madalln mu cky Silly ray loam

Middlebury and T,oijj a 511t loams

Mu ck and Peat

O",d s,ll loam, 0 to 6 percen t slopes O" 'd 5,lty clay loam , 6 10 12 percen t Slopes eroded Ov,,' ~ n d Rn ,neDer k sol t loams, m od pra te ly dee p, 0 to 2 percent ~loPf!s Ov.d and Rnl nebec~ silt loams mode'a !el v deep, 2 to 6 percent slopes Ov,d ~nd Rh In ebeck solt loams, moderatel y de ep, 6 t o 12 p,"rcenl slopes

Palmyra gravell y loam, 0 to 5 p,"rcent slOpes Palmyra gravelly loam, 5 to 15 o,""enl Sim p le s lope s Palmyra gra~elly loam, 5 10 15 Ol:'rCen! comple~ s lopes Palmyra gfavell" loam , 15 to 25 percent s lopes Phelps IiiIra"e lly s ill loam, 0 10 3 perce nt slopes Phelps IiiIrave lly Si ll loam, 3 to 8 percent slopes

Rtd Hoo~ i.avelly ~ 'II loam , 0 to 5 p erce n t SIOPt'S Rh inebeck s, lt loam, 0 to 2 percent slopes Rnonebeck. s,1t loam , 2 to 6 percent SlOPl:'5

Rh"'ebeck sol ty c lay loam, 6 to 12 p,"'cent ~IOpes, erO<l1;'d Rock outcrop

Tu ll er channery sol t loam, 0 to 6 percent slopes

Volu$,a channer" s, lt loam, 3 to 8 percent s lOpes VoluSla channery Silt loa m, 3 to 8 percenl SIOpl:'S, t roded VoluSla channery Silt loam, 8 to 15 percen t slope s Vo1U5,a cha nnery silt l oam, 8 to 15 percent slopes, efod ed Volus,a-Ch 'poewa channery S oi l loa ms, 0 10 3 pe fCent ~ I opes

Volus,a ,nd Ene So ol s, 15 to 25 percent slopes

Wayland and S loan sill loams

W,Iltamso" very ''''I' sandy loam , 2 to 6 perce"t slOPt S

TABLE 7/Legend for the general soil map of Thailand (Moormann and Rojanasoonthon, 7972).

EXCESSIVEL Y DRAINED SANDY SOILS. LOW FERTILITY

Ir PODRL Y DRAINED CLAYEY SOILS, HIGH TO MOOERA TE FERTILITY

[:::r::::J A ........ I I on 'K..-I lrelll ... 1 .............. ; ...... 10 .,,11, undII t"'l [:::r::::J AI"'.1oOl 1011 .. (.cld ....... 1. 1OOIs) on 'Kenl'" III •• 1. aI 111m; ....

CI::J AIIuv ... 1 .0 .... on 'K"- ,.,..... ....... .. •• 1 Anu .... 1 lOll .. I .... on fK.,,1 ", ...... 1'" ..... . ..

m VERY POORLY DRAI 0 ORGANIC SOILS (SWAMPS A 0 MARSHES)

v

PUI ."., .. lOlls; "lftl

POORL Y DRAINED AND WELL DRAINED SOILS. MOSTLY LOAMY AND SANOY. MODERATE TO LOW FERTILITY

lo. HumIC G", lOlls. "" ....... _1 ..-01 old .............. vel 10 .. IId .... 1

l H\.onoe G .. y 1Od .. ."., NoncMclC Br I0Il .. on .-Ir_ ~ ...... to .-wI"Llt"' .. L H ....... C"y lOlls"'" Gt.y PodzollC 1011 .... low · Hum .. G", loil, .IId R.., · V. PodzollC 10110 w,lh Lller '0 on oId.I...... . I 10 ""dlNl

WELL ORAl 0 TO SO WHAT POORLY DRAINED LOAMY A 0 CLAYEY SOILS. " MODERATE TO HIGH IN BASES. HI~H FERTILITY

G' .. m ........ ncI , laled ..... ",*ed 1011 .. on montm .. ~Ion'lfC cJa, "0", ..,......., ....... 1 .......... It . ... 1 10 uncl"lat ....

R_z ..... and 8r n Fo,nl lOll on ",,,1 "'" I""alt_ .l1li m . .......... 1"'. ofIC.aIcfC Br sail on .. _I .1'" ..... ; .... I 10 .. ndul.tt

ed 8, II t"thl. on f ...... ", "'" col'" """ Ifom "'SIC ,oeII, (mainly I,,,,nl_) ; undINl.... 10 ,oil

VI WELL TO EXCESSIVELY DRAINED LOAMY A 0 SANOY SOILS, LOW IN WEI. THERABLE MINERALS AND BASES. LOW FERTILITY.

VB

V.BI

--IX

G,., Podzok 1Od .. on old .......... . .... 1 10 _I

WELL DRAINED CLAYEY A 0 LOAMY SOILS, LOW IN BASES, LOW FERTILITY

Red Va Podz _I on old .1 ........... undII .. I ... 10 '011",. Red V. Podzol.. 1 ... ,1 .. I .......... 1.1 .. _ I'" ... Iace OIl old aItuvtum . ........ 1

R.d · y.llow Pod.OIfC """. on "lid" .... "'" c " ...... 11_ acld,oeII .......... 1 ... 10 Itup R.., 0 V. PodIOlfC .011. on relldwm .ncI colluv,.... Ifom Kid , on l1li1 . ..... 1 '0

WELL DRAINED CLAYEY AND LOAMY SOILS, HIGH IN ALUMINUM AND 10f'. IRON OXIDES. LOW IN BASES. MODERATE TO LOW FERTILITY R.cId,.h 8,own L..I.moe _Ion, SId\a.rn "'" collu ..... Ifom iIIl_l. and ......

,oc II; _I 10 "" "'. R.dd,Sh • Brow" lllOaoi on ",1CIuIm "'" cOllu........ ,om ..... It . _I 10,01 , .

Red 0 V.I lelO.... on old ... um . "_LlI,,, 10 ,."Ily ,oil

MISCELLANEOUS SOILS A 0 LAND TYPES ON HILLS, MOUNTAINS A 0 PLATEAUS

CE:J St_ Iat1d. "'''""ldiaM 10 ...... ,oeII .. _, Red YII PodJolfC IOds "'" R_ .. lal.,IK 1011 .. IillllOw 10 ~

_ Iat1d. "'" 10 .. ....-•• foell m"",, IIIaI R.., Y

Sit., lind. mlofll It_ a .... 1OIT1' Red Br n EMthi le •• PI... "'" ¥OIunoI, mMnIy -

Soil Maps / 17