United StatesDepartment ofAgriculture

NaturalResourcesConservationService

Soil Survey ofAdams County,Illinois

Part I

In cooperation withIllinois AgriculturalExperiment Station

The Natural Resources Conservation Service (NRCS) is committed to making itsinformation accessible to all of its customers and employees. If you are experiencingaccessibility issues and need assistance, please contact our Helpdesk by phone at1-800-457-3642 or by e-mail at helpdesk@helpdesk.itc.nrcs.usda.gov. For assistancewith publications that include maps, graphs, or similar forms of information, you mayalso wish to contact our State or local office. You can locate the correct office andphone number at http://offices.sc.egov.usda.gov/locator/app.

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Detailed Soil Maps

The detailed soil maps can be useful in planning the use and management of small areas.

To find information about your area of interest, locate that area on the Index to Map Sheets. Note the number ofthe map sheet, and turn to that sheet.

Locate your area of interest on the map sheet. Note the map unit symbols that are in that area. Turn to theContents in Part I, which lists the map units by symbol and name and shows the page where each map unit isdescribed.

The Contents in Part II shows which table has data on a specific land use for each detailed soil map unit. Also seethe Contents in Part I and Part II for sections of this publication that may address your specific needs.

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How To Use This Soil Survey

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Additional information about the Nation’s natural resources is available on theNatural Resources Conservation Service homepage on the World Wide Web. Theaddress is http://www.nrcs.usda.gov.

This soil survey is a publication of the National Cooperative Soil Survey, a joint effortof the United States Department of Agriculture and other Federal agencies, Stateagencies including the Agricultural Experiment Stations, and local agencies. TheNatural Resources Conservation Service (formerly the Soil Conservation Service) hasleadership for the Federal part of the National Cooperative Soil Survey.

Major fieldwork for this soil survey was completed in 1996. Soil names anddescriptions were approved in 1997. Unless otherwise indicated, statements in thispublication refer to conditions in the survey area in 1997. This survey was madecooperatively by the Natural Resources Conservation Service and the IllinoisAgricultural Experiment Station. It is part of the technical assistance furnished to theAdams County Soil and Water Conservation District. Financial assistance was providedby the Adams County Board and the Illinois Department of Agriculture.

Soil maps in this survey may be copied without permission. Enlargement of thesemaps, however, could cause misunderstanding of the detail of mapping. If enlarged,maps do not show the small areas of contrasting soils that could have been shown at alarger scale.

The United States Department of Agriculture (USDA) prohibits discrimination in all ofits programs on the basis of race, color, national origin, gender, religion, age, disability,political beliefs, sexual orientation, and marital or family status. (Not all prohibited basesapply to all programs.) Persons with disabilities who require alternative means forcommunication of program information (Braille, large print, audiotape, etc.) shouldcontact the USDA’s TARGET Center at 202-720-2600 (voice or TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights,Room 326W, Whitten Building, 14th and Independence Avenue SW, Washington, DC20250-9410, or call 202-720-5964 (voice or TDD). USDA is an equal opportunityprovider and employer.

Cover: An area of cropland in Adams County. Creal soils are in the foreground, and Lacrescentsoils are on the wooded side slopes.

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Contents

How To Use This Soil Survey ................................. 3Numerical Index to Map Units ............................. 10Foreword ............................................................... 13How This Survey Was Made ................................... 15General Nature of the County ................................. 16

History and Settlement ....................................... 17Agriculture .......................................................... 17Physiography, Relief, and Drainage .................... 17Climate ............................................................... 18

Formation and Classification of the Soils .......... 19Factors of Soil Formation ................................... 19

Parent Material ............................................... 19Climate ........................................................... 21Living Organisms ........................................... 22Relief and Drainage ....................................... 22Time ............................................................... 23

Classification of the Soils .................................... 23Soil Series and Detailed Soil Map Units .............. 25

Atlas Series ........................................................ 267C2—Atlas silt loam, 5 to 10 percent slopes,

eroded ......................................................... 277C3—Atlas silty clay loam, 5 to 10 percent

slopes, severely eroded ............................... 27Baylis Series ...................................................... 28472C2—Baylis silt loam, 5 to 10 percent

slopes, eroded ............................................. 29472D2—Baylis silt loam, 10 to 18 percent

slopes, eroded ............................................. 29472E2—Baylis silt loam, 18 to 25 percent

slopes, eroded ............................................. 30Beaucoup Series ................................................ 301070L—Beaucoup silty clay loam, 0 to 2

percent slopes, undrained, occasionallyflooded, long duration................................... 31

8070A—Beaucoup silty clay loam, 0 to 2percent slopes, occasionally flooded............ 32

Bethalto Series ................................................... 3290A—Bethalto silt loam, 0 to 2 percent

slopes .......................................................... 3390B—Bethalto silt loam, 2 to 5 percent

slopes .......................................................... 34Biggsville Series ................................................. 34671A—Biggsville silt loam, 0 to 2 percent

slopes .......................................................... 35

671B—Biggsville silt loam, 2 to 5 percentslopes .......................................................... 35

829B—Biggsville-Mannon silt loams, 1 to 7percent slopes ............................................. 36

Blake Series ....................................................... 363877L—Blake-Slacwater silt loams, 0 to 2

percent slopes, frequently flooded, longduration ........................................................ 37

Blyton Series ...................................................... 373634A—Blyton silt loam, 0 to 2 percent

slopes, frequently flooded ............................ 388634A—Blyton silt loam, 0 to 2 percent

slopes, occasionally flooded ........................ 38Bunkum Series ................................................... 39515B2—Bunkum silt loam, 2 to 5 percent

slopes, eroded ............................................. 40515C2—Bunkum silt loam, 5 to 10 percent

slopes, eroded ............................................. 41515C3—Bunkum silty clay loam, 5 to 10

percent slopes, severely eroded .................. 41515D2—Bunkum silt loam, 10 to 18 percent

slopes, eroded ............................................. 42515D3—Bunkum silty clay loam, 10 to 18

percent slopes, severely eroded .................. 42Caseyville Series ................................................ 43267A—Caseyville silt loam, 0 to 2 percent

slopes .......................................................... 44267B—Caseyville silt loam, 2 to 5 percent

slopes .......................................................... 44Clarksdale Series ............................................... 44257A—Clarksdale silt loam, 0 to 2 percent

slopes .......................................................... 46257B—Clarksdale silt loam, 2 to 5 percent

slopes .......................................................... 46Coatsburg Series ............................................... 47660C2—Coatsburg silt loam, 5 to 10

percent slopes, eroded ................................ 48Creal Series ....................................................... 48337A—Creal silt loam, 0 to 2 percent slopes ...... 50Crider Series ...................................................... 50629C2—Crider silt loam, 5 to 10 percent

slopes, eroded ............................................. 51629D2—Crider silt loam, 10 to 18 percent

slopes, eroded ............................................. 51

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Downsouth Series .............................................. 51283B—Downsouth silt loam, 2 to 5 percent

slopes .......................................................... 53283C2—Downsouth silt loam, 5 to 10 percent

slopes, eroded ............................................. 53Drury Series ....................................................... 5475A—Drury silt loam, 0 to 2 percent slopes ....... 5475B—Drury silt loam, 2 to 5 percent slopes ....... 5575C2—Drury silt loam, 5 to 10 percent

slopes, eroded ............................................. 55Dupo Series ....................................................... 568180A—Dupo silt loam, 0 to 2 percent

slopes, occasionally flooded ........................ 57Edwardsville Series ............................................ 57384A—Edwardsville silt loam, 0 to 2 percent

slopes .......................................................... 58384B—Edwardsville silt loam, 2 to 5 percent

slopes .......................................................... 59El Dara Series .................................................... 59264C2—El Dara silt loam, 5 to 10 percent

slopes, eroded ............................................. 61264D2—El Dara silt loam, 10 to 18 percent

slopes, eroded ............................................. 61264D3—El Dara sandy loam, 10 to 18

percent slopes, severely eroded .................. 62264E2—El Dara sandy loam, 18 to 25

percent slopes, eroded ................................ 62264G—El Dara fine sandy loam, 35 to 60

percent slopes ............................................. 63Elsah Series ....................................................... 633475A—Elsah gravelly loam, 0 to 2 percent

slopes, frequently flooded ............................ 64Emery Series ..................................................... 64538B2—Emery silt loam, 2 to 5 percent

slopes, eroded ............................................. 65538C2—Emery silt loam, 5 to 10 percent

slopes, eroded ............................................. 66Fishhook Series ................................................. 666B2—Fishhook silt loam, 2 to 5 percent

slopes, eroded ............................................. 676C2—Fishhook silt loam, 5 to 10 percent

slopes, eroded ............................................. 686C3—Fishhook silty clay loam, 5 to 10

percent slopes, severely eroded .................. 68

6D2—Fishhook silt loam, 10 to 18 percentslopes, eroded ............................................. 69

6D3—Fishhook silty clay loam, 10 to 18percent slopes, severely eroded .................. 69

Gorham Series ................................................... 708162A—Gorham silty clay loam, 0 to 2

percent slopes, occasionally flooded............ 71Goss Series ....................................................... 71606F—Goss gravelly silt loam, 18 to 35

percent slopes ............................................. 72606G—Goss gravelly silt loam, 35 to 60

percent slopes ............................................. 72Greenbush Series .............................................. 72675B—Greenbush silt loam, 2 to 5 percent

slopes .......................................................... 73675C2—Greenbush silt loam, 5 to 10

percent slopes, eroded ................................ 74Haymond Series ................................................. 743331A—Haymond silt loam, 0 to 2 percent

slopes, frequently flooded ............................ 75Hickory Series .................................................... 758E2—Hickory loam, 18 to 25 percent

slopes, eroded ............................................. 778F—Hickory silt loam, 18 to 35 percent

slopes .......................................................... 778G—Hickory silt loam, 35 to 60 percent

slopes .......................................................... 77Huntsville Series ................................................ 788077A—Huntsville silt loam, 0 to 2 percent

slopes, occasionally flooded ........................ 78Ipava Series ....................................................... 79855A—Timewell and Ipava soils, 0 to 2

percent slopes ............................................. 80855B—Timewell and Ipava soils, 2 to 5

percent slopes ............................................. 81Keller Series ....................................................... 81470B2—Keller silt loam, 2 to 5 percent

slopes, eroded ............................................. 82470C—Keller silt loam, 5 to 10 percent

slopes .......................................................... 83470C2—Keller silt loam, 5 to 10 percent

slopes, eroded ............................................. 83Keomah Series ................................................... 8417A—Keomah silt loam, 0 to 2 percent slopes ... 85

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17B—Keomah silt loam, 2 to 5 percentslopes .......................................................... 85

Keswick Series ................................................... 86651C2—Keswick loam, 5 to 10 percent

slopes, eroded ............................................. 87651C3—Keswick clay loam, 5 to 10 percent

slopes, severely eroded ............................... 87651D2—Keswick loam, 10 to 18 percent

slopes, eroded ............................................. 88651D3—Keswick clay loam, 10 to 18 percent

slopes, severely eroded ............................... 88651E2—Keswick loam, 18 to 25 percent

slopes, eroded ............................................. 89Lacrescent Series .............................................. 89785G—Lacrescent channery silt loam, 35 to

60 percent slopes ........................................ 90Lamont Series .................................................... 91175F—Lamont sandy loam, 18 to 35 percent

slopes .......................................................... 92175G—Lamont sandy loam, 35 to 60 percent

slopes .......................................................... 92Lawson Series .................................................... 933451A—Lawson silt loam, 0 to 2 percent

slopes, frequently flooded ............................ 938451A—Lawson silt loam, 0 to 2 percent

slopes, occasionally flooded ........................ 94Lenzburg Series ................................................. 94871G—Lenzburg silty clay loam, 20 to 60

percent slopes ............................................. 95Lindley Series ..................................................... 95559F—Lindley loam, 18 to 35 percent

slopes .......................................................... 96559G—Lindley loam, 35 to 60 percent

slopes .......................................................... 97Littleton Series ................................................... 9781A—Littleton silt loam, 0 to 2 percent

slopes .......................................................... 98Mannon Series ................................................... 98678A—Mannon silt loam, 0 to 2 percent

slopes .......................................................... 99678B—Mannon silt loam, 2 to 5 percent

slopes ........................................................ 100829B—Biggsville-Mannon silt loams, 1 to 7

percent slopes ........................................... 100

Marseilles Series .............................................. 100549D2—Marseilles silt loam, 10 to 18

percent slopes, eroded .............................. 101549D3—Marseilles silty clay loam, 10 to

18 percent slopes, severely eroded ........... 102549F—Marseilles silt loam, 18 to 35

percent slopes ........................................... 102549G—Marseilles silt loam, 35 to 60

percent slopes ........................................... 102Menfro Series ................................................... 10379B—Menfro silt loam, 2 to 5 percent

slopes ........................................................ 10479C2—Menfro silt loam, 5 to 10 percent

slopes, eroded ........................................... 10479C3—Menfro silty clay loam, 5 to 10

percent slopes, severely eroded ................ 10579D2—Menfro silt loam, 10 to 18 percent

slopes, eroded ........................................... 10579D3—Menfro silty clay loam, 10 to 18

percent slopes, severely eroded ................ 106801B—Orthents, silty, undulating ..................... 106Osco Series ..................................................... 10786B—Osco silt loam, 2 to 5 percent slopes ...... 108Passport Series ................................................ 108652C2—Passport silt loam, 5 to 10 percent

slopes, eroded ........................................... 109652C3—Passport silty clay loam, 5 to 10

percent slopes, severely eroded ................ 110864—Pits, quarries ........................................... 110Raveenwash Series ......................................... 1113368L—Raveenwash silt loam, 0 to 2

percent slopes, frequently flooded,long duration .............................................. 111

Riley Series ...................................................... 1128452A—Riley silty clay loam, 0 to 2 percent

slopes, occasionally flooded ...................... 113Ross Series ...................................................... 1138073A—Ross silt loam, 0 to 2 percent

slopes, occasionally flooded ...................... 114Rozetta Series .................................................. 114279B—Rozetta silt loam, 2 to 5 percent

slopes ........................................................ 115279C2—Rozetta silt loam, 5 to 10 percent

slopes, eroded ........................................... 116

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279C3—Rozetta silty clay loam, 5 to 10percent slopes, severely eroded ................ 116

Rubio Series..................................................... 117111A—Rubio silt loam, 0 to 2 percent

slopes ........................................................ 117Rushville Series ............................................... 11816A—Rushville silt loam, 0 to 2 percent

slopes ........................................................ 119Sarpy Series .................................................... 1198092A—Sarpy sand, 0 to 2 percent slopes,

occasionally flooded................................... 120Slacwater Series .............................................. 1213877L—Blake-Slacwater silt loams, 0 to 2

percent slopes, frequently flooded, longduration ...................................................... 121

Sparta Series ................................................... 12288B—Sparta loamy sand, 1 to 6 percent

slopes ........................................................ 122Stookey Series ................................................. 123216B—Stookey silt loam, 2 to 5 percent

slopes ........................................................ 124216C2—Stookey silt loam, 5 to 10 percent

slopes, eroded ........................................... 124216C3—Stookey silt loam, 5 to 10 percent

slopes, severely eroded ............................. 125216D2—Stookey silt loam, 10 to 18 percent

slopes, eroded ........................................... 125216D3—Stookey silt loam, 10 to 18 percent

slopes, severely eroded ............................. 126816B—Stookey-Timula-Orthents complex,

1 to 7 percent slopes.................................. 126816D—Stookey-Timula-Orthents complex,

7 to 15 percent slopes................................ 126856F—Stookey and Timula soils, 18 to 35

percent slopes ........................................... 127856G—Stookey and Timula soils, 35 to 60

percent slopes ........................................... 127Tice Series ....................................................... 1288284A—Tice silty clay loam, 0 to 2 percent

slopes, occasionally flooded ...................... 129Timewell Series ................................................ 129855A—Timewell and Ipava soils, 0 to 2

percent slopes ........................................... 131

855B—Timewell and Ipava soils, 2 to 5percent slopes ........................................... 131

Timula Series ................................................... 132271C2—Timula silt loam, 5 to 10 percent

slopes, eroded ........................................... 133271D2—Timula silt loam, 10 to 18 percent

slopes, eroded ........................................... 133816B—Stookey-Timula-Orthents complex,

1 to 7 percent slopes.................................. 134816D—Stookey-Timula-Orthents complex,

7 to 15 percent slopes................................ 134856F—Stookey and Timula soils, 18 to 35

percent slopes ........................................... 134856G—Stookey and Timula soils, 35 to 60

percent slopes ........................................... 135Titus Series ...................................................... 1358404A—Titus silty clay loam, 0 to 2 percent

slopes, occasionally flooded ...................... 136Twomile Series ................................................. 1378217A—Twomile silt loam, 0 to 2 percent

slopes, occasionally flooded ...................... 138Ursa Series ...................................................... 138655C2—Ursa silt loam, moderately wet,

5 to 10 percent slopes, eroded ................... 140655C3—Ursa silty clay loam, moderately

wet, 5 to 10 percent slopes, severelyeroded ....................................................... 140

655D2—Ursa silt loam, moderately wet,10 to 18 percent slopes, eroded ................. 140

655D3—Ursa silty clay loam, moderatelywet, 10 to 18 percent slopes, severelyeroded ....................................................... 141

Vesser Series ................................................... 1413396A—Vesser silt loam, 0 to 2 percent

slopes, frequently flooded .......................... 1428396A—Vesser silt loam, 0 to 2 percent

slopes, occasionally flooded ...................... 143Virden Series .................................................... 14350A—Virden silty clay loam, 0 to 2 percent

slopes ........................................................ 144Wakeland Series .............................................. 1443333A—Wakeland silt loam, 0 to 2 percent

slopes, frequently flooded .......................... 145

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8333A—Wakeland silt loam, 0 to 2 percentslopes, occasionally flooded ...................... 145

Wakenda Series ............................................... 146441B—Wakenda silt loam, 2 to 5 percent

slopes ........................................................ 147Winfield Series ................................................. 147477B—Winfield silt loam, 2 to 5 percent

slopes ........................................................ 148477C2—Winfield silt loam, 5 to 10 percent

slopes, eroded ........................................... 149477C3—Winfield silty clay loam, 5 to 10

percent slopes, severely eroded ................ 149Wirt Series ....................................................... 1503226A—Wirt silt loam, 0 to 2 percent

slopes, frequently flooded .......................... 150Worthen Series ................................................ 151

37A—Worthen silt loam, 0 to 2 percentslopes ........................................................ 151

37B—Worthen silt loam, 2 to 5 percentslopes ........................................................ 152

Zumbro Series.................................................. 1528349B—Zumbro sandy loam, 1 to 6 percent

slopes, occasionally flooded ...................... 153References .......................................................... 155Glossary .............................................................. 157Tables .................................................................. 169

Table 1.—Temperature and Precipitation .......... 170Table 2.—Freeze Dates in Spring and Fall ........ 171Table 3.—Growing Season ............................... 171Table 4.—Classification of the Soils .................. 172Table 5.—Acreage and Proportionate

Extent of the Soils ...................................... 174

Issued 2003

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6B2—Fishhook silt loam, 2 to 5 percent slopes,eroded ................................................................ 67

6C2—Fishhook silt loam, 5 to 10 percent slopes,eroded ................................................................ 68

6C3—Fishhook silty clay loam, 5 to 10 percentslopes, severely eroded ...................................... 68

6D2—Fishhook silt loam, 10 to 18 percentslopes, eroded .................................................... 69

6D3—Fishhook silty clay loam, 10 to 18 percentslopes, severely eroded ...................................... 69

7C2—Atlas silt loam, 5 to 10 percent slopes,eroded ................................................................ 27

7C3—Atlas silty clay loam, 5 to 10 percentslopes, severely eroded ...................................... 27

8E2—Hickory loam, 18 to 25 percent slopes,eroded ................................................................ 77

8F—Hickory silt loam, 18 to 35 percentslopes ................................................................. 77

8G—Hickory silt loam, 35 to 60 percentslopes ................................................................. 77

16A—Rushville silt loam, 0 to 2 percentslopes ............................................................... 119

17A—Keomah silt loam, 0 to 2 percentslopes ................................................................. 85

17B—Keomah silt loam, 2 to 5 percentslopes ................................................................. 85

37A—Worthen silt loam, 0 to 2 percentslopes ............................................................... 151

37B—Worthen silt loam, 2 to 5 percentslopes ............................................................... 152

50A—Virden silty clay loam, 0 to 2 percentslopes ............................................................... 144

75A—Drury silt loam, 0 to 2 percent slopes ............ 5475B—Drury silt loam, 2 to 5 percent slopes ............ 5575C2—Drury silt loam, 5 to 10 percent slopes,

eroded ................................................................ 5579B—Menfro silt loam, 2 to 5 percent slopes ....... 10479C2—Menfro silt loam, 5 to 10 percent slopes,

eroded .............................................................. 10479C3—Menfro silty clay loam, 5 to 10 percent

slopes, severely eroded .................................... 10579D2—Menfro silt loam, 10 to 18 percent

slopes, eroded .................................................. 10579D3—Menfro silty clay loam, 10 to 18 percent

slopes, severely eroded .................................... 106

81A—Littleton silt loam, 0 to 2 percent slopes ........ 9886B—Osco silt loam, 2 to 5 percent slopes .......... 10888B—Sparta loamy sand, 1 to 6 percent slopes ... 12290A—Bethalto silt loam, 0 to 2 percent slopes........ 3390B—Bethalto silt loam, 2 to 5 percent slopes........ 34111A—Rubio silt loam, 0 to 2 percent slopes ....... 117175F—Lamont sandy loam, 18 to 35 percent

slopes ................................................................. 92175G—Lamont sandy loam, 35 to 60 percent

slopes ................................................................. 92216B—Stookey silt loam, 2 to 5 percent slopes .... 124216C2—Stookey silt loam, 5 to 10 percent

slopes, eroded .................................................. 124216C3—Stookey silt loam, 5 to 10 percent

slopes, severely eroded .................................... 125216D2—Stookey silt loam, 10 to 18 percent

slopes, eroded .................................................. 125216D3—Stookey silt loam, 10 to 18 percent

slopes, severely eroded .................................... 126257A—Clarksdale silt loam, 0 to 2 percent

slopes ................................................................. 46257B—Clarksdale silt loam, 2 to 5 percent

slopes ................................................................. 46264C2—El Dara silt loam, 5 to 10 percent

slopes, eroded .................................................... 61264D2—El Dara silt loam, 10 to 18 percent

slopes, eroded .................................................... 61264D3—El Dara sandy loam, 10 to 18 percent

slopes, severely eroded ...................................... 62264E2—El Dara sandy loam, 18 to 25 percent

slopes, eroded .................................................... 62264G—El Dara fine sandy loam, 35 to 60

percent slopes .................................................... 63267A—Caseyville silt loam, 0 to 2 percent

slopes ................................................................. 44267B—Caseyville silt loam, 2 to 5 percent

slopes ................................................................. 44271C2—Timula silt loam, 5 to 10 percent

slopes, eroded .................................................. 133271D2—Timula silt loam, 10 to 18 percent

slopes, eroded .................................................. 133279B—Rozetta silt loam, 2 to 5 percent

slopes ............................................................... 115279C2—Rozetta silt loam, 5 to 10 percent

slopes, eroded .................................................. 116

Numerical Index to Map Units

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279C3—Rozetta silty clay loam, 5 to 10 percentslopes, severely eroded .................................... 116

283B—Downsouth silt loam, 2 to 5 percentslopes ................................................................. 53

283C2—Downsouth silt loam, 5 to 10 percentslopes, eroded .................................................... 53

337A—Creal silt loam, 0 to 2 percentslopes ................................................................. 50

384A—Edwardsville silt loam, 0 to 2 percentslopes ................................................................. 58

384B—Edwardsville silt loam, 2 to 5 percentslopes ................................................................. 59

441B—Wakenda silt loam, 2 to 5 percentslopes ............................................................... 147

470B2—Keller silt loam, 2 to 5 percent slopes,eroded ................................................................ 82

470C—Keller silt loam, 5 to 10 percentslopes ................................................................. 83

470C2—Keller silt loam, 5 to 10 percentslopes, eroded .................................................... 83

472C2—Baylis silt loam, 5 to 10 percentslopes, eroded .................................................... 29

472D2—Baylis silt loam, 10 to 18 percentslopes, eroded .................................................... 29

472E2—Baylis silt loam, 18 to 25 percentslopes, eroded .................................................... 30

477B—Winfield silt loam, 2 to 5 percentslopes ............................................................... 148

477C2—Winfield silt loam, 5 to 10 percentslopes, eroded .................................................. 149

477C3—Winfield silty clay loam, 5 to 10percent slopes, severely eroded ....................... 149

515B2—Bunkum silt loam, 2 to 5 percentslopes, eroded .................................................... 40

515C2—Bunkum silt loam, 5 to 10 percentslopes, eroded .................................................... 41

515C3—Bunkum silty clay loam, 5 to 10percent slopes, severely eroded ......................... 41

515D2—Bunkum silt loam, 10 to 18 percentslopes, eroded .................................................... 42

515D3—Bunkum silty clay loam, 10 to 18percent slopes, severely eroded ......................... 42

538B2—Emery silt loam, 2 to 5 percent slopes,eroded ................................................................ 65

538C2—Emery silt loam, 5 to 10 percentslopes, eroded .................................................... 66

549D2—Marseilles silt loam, 10 to 18 percentslopes, eroded .................................................. 101

549D3—Marseilles silty clay loam, 10 to 18percent slopes, severely eroded ....................... 102

549F—Marseilles silt loam, 18 to 35 percentslopes ............................................................... 102

549G—Marseilles silt loam, 35 to 60 percentslopes ............................................................... 102

559F—Lindley loam, 18 to 35 percentslopes ................................................................. 96

559G—Lindley loam, 35 to 60 percentslopes ................................................................. 97

606F—Goss gravelly silt loam, 18 to 35percent slopes .................................................... 72

606G—Goss gravelly silt loam, 35 to 60percent slopes .................................................... 72

629C2—Crider silt loam, 5 to 10 percentslopes, eroded .................................................... 51

629D2—Crider silt loam, 10 to 18 percentslopes, eroded .................................................... 51

651C2—Keswick loam, 5 to 10 percent slopes,eroded ................................................................ 87

651C3—Keswick clay loam, 5 to 10 percentslopes, severely eroded ...................................... 87

651D2—Keswick loam, 10 to 18 percentslopes, eroded .................................................... 88

651D3—Keswick clay loam, 10 to 18 percentslopes, severely eroded ...................................... 88

651E2—Keswick loam, 18 to 25 percent slopes,eroded ................................................................ 89

652C2—Passport silt loam, 5 to 10 percentslopes, eroded .................................................. 109

652C3—Passport silty clay loam, 5 to 10percent slopes, severely eroded ....................... 110

655C2—Ursa silt loam, moderately wet, 5 to10 percent slopes, eroded ................................ 140

655C3—Ursa silty clay loam, moderately wet,5 to 10 percent slopes, severely eroded ........... 140

655D2—Ursa silt loam, moderately wet, 10to 18 percent slopes, eroded ............................ 140

655D3—Ursa silty clay loam, moderately wet,10 to 18 percent slopes, severely eroded ......... 141

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660C2—Coatsburg silt loam, 5 to 10 percentslopes, eroded .................................................... 48

671A—Biggsville silt loam, 0 to 2 percentslopes ................................................................. 35

671B—Biggsville silt loam, 2 to 5 percentslopes ................................................................. 35

675B—Greenbush silt loam, 2 to 5 percentslopes ................................................................. 73

675C2—Greenbush silt loam, 5 to 10 percentslopes, eroded .................................................... 74

678A—Mannon silt loam, 0 to 2 percentslopes ................................................................. 99

678B—Mannon silt loam, 2 to 5 percentslopes ............................................................... 100

785G—Lacrescent channery silt loam, 35 to60 percent slopes ............................................... 90

801B—Orthents, silty, undulating .......................... 106816B—Stookey-Timula-Orthents complex, 1

to 7 percent slopes ........................................... 126816D—Stookey-Timula-Orthents complex, 7

to 15 percent slopes ......................................... 126829B—Biggsville-Mannon silt loams, 1 to 7

percent slopes .................................................... 36855A—Timewell and Ipava soils, 0 to 2 percent

slopes ............................................................... 131855B—Timewell and Ipava soils, 2 to 5 percent

slopes ............................................................... 131856F—Stookey and Timula soils, 18 to 35

percent slopes .................................................. 127856G—Stookey and Timula soils, 35 to 60

percent slopes .................................................. 127864—Pits, quarries ............................................... 110871G—Lenzburg silty clay loam, 20 to 60

percent slopes .................................................... 951070L—Beaucoup silty clay loam, 0 to 2

percent slopes, undrained, occasionallyflooded, long duration ......................................... 31

3226A—Wirt silt loam, 0 to 2 percent slopes,frequently flooded ............................................. 150

3331A—Haymond silt loam, 0 to 2 percentslopes, frequently flooded................................... 75

3333A—Wakeland silt loam, 0 to 2 percentslopes, frequently flooded................................. 145

3368L—Raveenwash silt loam, 0 to 2 percentslopes, frequently flooded, long duration .......... 111

3396A—Vesser silt loam, 0 to 2 percent slopes,frequently flooded ............................................. 142

3451A—Lawson silt loam, 0 to 2 percentslopes, frequently flooded................................... 93

3475A—Elsah gravelly loam, 0 to 2 percentslopes, frequently flooded................................... 64

3634A—Blyton silt loam, 0 to 2 percent slopes,frequently flooded ............................................... 38

3877L—Blake-Slacwater silt loams, 0 to 2percent slopes, frequently flooded, longduration .............................................................. 37

8070A—Beaucoup silty clay loam, 0 to 2percent slopes, occasionally flooded .................. 32

8073A—Ross silt loam, 0 to 2 percent slopes,occasionally flooded ......................................... 114

8077A—Huntsville silt loam, 0 to 2 percentslopes, occasionally flooded ............................... 78

8092A—Sarpy sand, 0 to 2 percent slopes,occasionally flooded ......................................... 120

8162A—Gorham silty clay loam, 0 to 2 percentslopes, occasionally flooded ............................... 71

8180A—Dupo silt loam, 0 to 2 percent slopes,occasionally flooded ........................................... 57

8217A—Twomile silt loam, 0 to 2 percentslopes, occasionally flooded ............................. 138

8284A—Tice silty clay loam, 0 to 2 percentslopes, occasionally flooded ............................. 129

8333A—Wakeland silt loam, 0 to 2 percentslopes, occasionally flooded ............................. 145

8349B—Zumbro sandy loam, 1 to 6 percentslopes, occasionally flooded ............................. 153

8396A—Vesser silt loam, 0 to 2 percentslopes, occasionally flooded ............................. 143

8404A—Titus silty clay loam, 0 to 2 percentslopes, occasionally flooded ............................. 136

8451A—Lawson silt loam, 0 to 2 percentslopes, occasionally flooded ............................... 94

8452A—Riley silty clay loam, 0 to 2 percentslopes, occasionally flooded ............................. 113

8634A—Blyton silt loam, 0 to 2 percentslopes, occasionally flooded ............................... 38

13

This soil survey contains information that affects land use planning in Adams County.It contains predictions of soil behavior for selected land uses. The survey also highlightssoil limitations, improvements needed to overcome the limitations, and the impact ofselected land uses on the environment.

This soil survey is designed for many different users. Farmers, foresters, andagronomists can use it to evaluate the potential of the soil and the management neededfor maximum food and fiber production. Planners, community officials, engineers,developers, builders, and home buyers can use the survey to plan land use, select sitesfor construction, and identify special practices needed to ensure proper performance.Conservationists, teachers, students, and specialists in recreation, wildlifemanagement, waste disposal, and pollution control can use the survey to help themunderstand, protect, and enhance the environment.

Various land use regulations of Federal, State, and local governments may imposespecial restrictions on land use or land treatment. The information in this report isintended to identify soil properties that are used in making various land use or landtreatment decisions. Statements made in this report are intended to help the land usersidentify and reduce the effects of soil limitations on various land uses. The landowner oruser is responsible for identifying and complying with existing laws and regulations.

Great differences in soil properties can occur within short distances. Some soils areseasonally wet or subject to flooding. Some are shallow to bedrock. Some are toounstable to be used as a foundation for buildings or roads. Clayey or wet soils arepoorly suited to use as septic tank absorption fields. A high water table makes a soilpoorly suited to basements or underground installations.

These and many other soil properties that affect land use are described in this soilsurvey. The location of each soil is shown on the detailed soil maps. Each soil in thesurvey area is described, and information on specific uses is given. Help in using thispublication and additional information are available at the local office of the NaturalResources Conservation Service or the Cooperative Extension Service.

William J. GradleState ConservationistNatural Resources Conservation Service

Foreword

15

How This Survey Was MadeThis survey was made to provide information about

the soils and miscellaneous areas in the survey area.The information includes a description of the soils andmiscellaneous areas and their location and adiscussion of their suitability, limitations, andmanagement for specified uses. Soil scientistsobserved the steepness, length, and shape of theslopes; the general pattern of drainage; the kinds ofcrops and native plants; and the kinds of bedrock.They dug many holes to study the soil profile, which isthe sequence of natural layers, or horizons, in a soil.The profile extends from the surface down into theunconsolidated material in which the soil formed. Theunconsolidated material is devoid of roots and otherliving organisms and has not been changed by otherbiological activity.

The soils and miscellaneous areas in the surveyarea are in an orderly pattern that is related to thegeology, landforms, relief, climate, and naturalvegetation of the area. Each kind of soil andmiscellaneous area is associated with a particular kindof landform or with a segment of the landform. Byobserving the soils and miscellaneous areas in thesurvey area and relating their position to specificsegments of the landform, a soil scientist develops aconcept, or model, of how they were formed. Thus,during mapping, this model enables the soil scientist

to predict with a considerable degree of accuracy thekind of soil or miscellaneous area at a specific locationon the landscape.

Commonly, individual soils on the landscape mergeinto one another as their characteristics graduallychange. To construct an accurate soil map, however,soil scientists must determine the boundaries betweenthe soils. They can observe only a limited number ofsoil profiles. Nevertheless, these observations,supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient toverify predictions of the kinds of soil in an area and todetermine the boundaries.

Fieldwork in Adams County consisted primarily ofsoil transects conducted by soil scientists. Soiltransects provide a systematic method for sampling aspecific soil type. Soil borings are taken at regularintervals. Soil scientists then record the characteristicsof the soil profiles that they studied. They note soilcolor, texture, size and shape of soil aggregates, kindand amount of rock fragments, distribution of plantroots, reaction, and other features. This informationcan then be used to run statistical analyses for specificsoil properties. The results of these analyses, alongwith other observations, enable the soil scientists toassign the soils to taxonomic classes (units).Taxonomic classes are concepts. Each taxonomicclass has a set of soil characteristics with preciselydefined limits. The classes are used as a basis for

Soil Survey of

Adams County, IllinoisBy Robert A. Tegeler, Natural Resources Conservation Service

Fieldwork by Ronald D. Collman, Charles Love, and Robert A. Tegeler,Natural Resources Conservation Service

Map compilation by Ronald D. Collman, James K. Hornickel, Paula K. Shannon,Robert A. Tegeler, William M. Teater, Tonie J. Endres, Gerald V. Berning, andKenneth A. Gotsch

United States Department of Agriculture, Natural Resources Conservation Service,in cooperation withthe Illinois Agricultural Experiment Station

16 Soil Survey of

comparison to classify soils systematically. Soiltaxonomy, the system of taxonomic classification usedin the United States, is based mainly on the kind andcharacter of soil properties and the arrangement ofhorizons within the profile. After the soil scientistsclassified and named the soils in the survey area, theycompared the individual soils with similar soils in thesame taxonomic class in other areas so that theycould confirm data and assemble additional databased on experience and research.

While a soil survey is in progress, samples of someof the soils in the area generally are collected forlaboratory analyses. Soil scientists interpret the datafrom these analyses as well as the field-observedcharacteristics and the soil properties to determine theexpected behavior of the soils under different uses.Interpretations for all of the soils are field testedthrough observation of the soils in different uses andunder different levels of management. Someinterpretations are modified to fit local conditions, andsome new interpretations are developed to meet localneeds. Data are assembled from other sources, suchas research information, production records, and fieldexperience of specialists. For example, data on cropyields under defined levels of management areassembled from farm records and from field or plotexperiments on the same kinds of soil.

Predictions about soil behavior are based not onlyon soil properties but also on such variables asclimate and biological activity. Soil conditions arepredictable over long periods of time, but they are notpredictable from year to year. For example, soilscientists can predict with a fairly high degree ofaccuracy that a given soil will have a high water tablewithin certain depths in most years, but they cannotpredict that a high water table will always be at aspecific level in the soil on a specific date.

Aerial photographs used in this survey were takenin 1993, 1994, 1995, and 1996. Soil scientists alsostudied U.S. Geological Survey topographic maps(enlarged to a scale of 1:12,000) andorthophotographs to relate land and image features.Specific soil boundaries were drawn on theorthophotographs. Soil boundary lines were adjustedto coincide with the U.S. Geological Surveytopographic map contour lines and tonal patterns onaerial photographs.

The descriptions, names, and delineations of thesoils in this survey area do not fully agree with thoseof the soils in adjacent survey areas. Differences arethe result of a better knowledge of soils, modificationsin series concepts, or variations in the intensity ofmapping or in the extent of the soils in the surveyareas.

General Nature of the CountyPam Peter, resource conservationist, Adams County Soil and

Water Conservation District, helped prepare this section.

Adams County is the westernmost county in Illinois(fig. 1). It is bounded by Hancock County on the north;by Schuyler, Brown, and Pike Counties on the east; byPike County on the south; and by the Mississippi Riveron the west. The total area of the county, includingwater, is 557,470 acres (U.S. Department ofCommerce, 1994). In 1994, the population of AdamsCounty was 66,329. Quincy, the county seat andlargest city in the county, had a population of 39,859(Two Rivers Regional Council of Public Officials,1994).

This soil survey updates an earlier survey of Adams

Springfield

Figure 1.—Location of Adams County in Illinois.

Adams County, Illinois—Part I 17

County published in 1979 (Bushue, 1979). It providesadditional data and updated soil interpretations andhas larger maps, which show the soils in greaterdetail.

History and Settlement

The first Europeans to visit the survey area werethe two great French explorers, Father Marquette andLouis Joliet, who traveled the upper Mississippi Riverin 1673. Adams County was established as aseparate county in 1825. The county’s first settler wasJustus I. Perigo, who settled in what is now Fall CreekTownship in the southwestern part of the county in1821.

The founder of Adams County and the city ofQuincy was John Wood. Wood later became StateSenator, Lieutenant Governor, and Governor of Illinois.He was an outstanding officer in the Civil War. Hishome, a Southern-style mansion, now houses theQuincy Historical Society and is one of the PrairieState’s leading architectural and historic landmarks.

In 1858, the sixth Lincoln-Douglas debate tookplace in Quincy at the present site of Washington Park.It is estimated that 10,000 to 12,000 people attendedthis debate (Drury, 1955).

Adams County has well developed transportationfacilities. These include Federal and State Highways,railroads, buses, barges, and an airfield. U.S.Highways 24 and 172 and State Highways 57, 61, 94,96, and 104 provide good access to cities, towns, andoutlying areas throughout the county.

Agriculture

Agriculture is a major economic force in AdamsCounty. In 1992, the county had 1,500 farms thatmade up 464,834 acres. The average farm size was310 acres (U.S. Department of Commerce, 1994). In1996, Adams County ranked among the top tencounties in Illinois in numbers of total cattle and innumbers of milk cattle and beef cattle. Corn,soybeans, wheat, and hay are the major crops. In1996, about 153,000 acres was used for corn, about126,000 acres was used for soybeans, about 36,400acres was used for wheat, and about 24,600 acreswas used for hay. Also grown in the county aresorghum and specialty crops, such as sweet corn,sod, ornamental plants, and nursery stock. There areseveral orchards. Hogs and cattle are the mainlivestock. In 1996, the number of swine was 93,500and the number of cattle was 42,300 (IllinoisDepartment of Agriculture and USDA, 1997).

Physiography, Relief, and Drainage

Adams County has extremes in topography. Themajority of the county lies in the Galesburg Plain, butthe western edge of the county is in the Dissected TillPlains Section. Both of these physiographic divisionsare part of the Central Lowland Province (Leightonand others, 1948). The northeastern and central partsof the county have large, nearly level areas that arepart of a relatively undissected upland drainage dividebetween the Mississippi and Illinois Rivers. Otherlarge nearly level areas are on the flood plain alongthe Mississippi River. Small nearly level areas andlarger gently sloping to very steep areas are in otherparts of the county. The present topography is mainlythe result of erosion, even though the Illinoianterminal moraine extends from about thenorthwestern part of the county to the southeasternpart. The highest point in the county is about 860 feetabove sea level and is near the southwest corner ofthe county. The lowest point is about 460 feet abovesea level and is on the flood plain along the MississippiRiver near the southwest corner of the county. Ofinterest is a home belonging to the Funk family nearthe village of Beverly. Water falling on the east side ofthe home drains into the Mississippi River, and waterfalling on the west side of the home drains into theIllinois River.

Pigeon, Mill, and Bear Creeks are the majortributaries to the Mississippi River from Adams County.The Illinois River basin is drained by McKee Creekand tributaries of the LaMoine River.

Soils in the upland areas of the county formedmainly in loess and glacial drift. The combinedthickness of these materials is mostly 30 to 60 feet.The soils on bottom land formed in sandy to clayeywater-deposited material. This material is more than100 feet thick throughout most of the Mississippi Riverflood plain and 5 to 50 feet thick on small flood plainsin the county.

The native vegetation of Adams County wasprimarily hardwood timber, but the nearly levelprairie areas in the northeastern and central partsof the county supported native prairie grasses andforbs.

Water is plentiful on most of the flood plain alongthe Mississippi River. In the upland part of the county,the supply of water is generally sufficient for farm use.Most wells are drilled into limestone or, in places, intosand or gravel beds in the glacial drift. More than2,500 water impoundments cover nearly 2,700 acresin Adams County. Several rural water districts serveAdams County and its towns and villages.

18

Climate

Table 1 gives data on temperature and precipitationfor the survey area as recorded at Quincy in the period1961 to 1990. Table 2 shows probable dates of the firstfreeze in fall and the last freeze in spring. Table 3provides data on length of the growing season.

In winter, the average temperature is 27.1 degreesF and the average daily minimum temperature is 19.0degrees. The lowest temperature on record, whichoccurred on December 22, 1989, is -22 degrees. Insummer, the average temperature is 74.3 degrees andthe average daily maximum temperature is 84.4degrees. The highest recorded temperature, whichoccurred on July 14, 1954, is 112 degrees.

Growing degree days are shown in table 1. Theyare equivalent to “heat units.” During the month,growing degree days accumulate by the amount thatthe average temperature each day exceeds a basetemperature (40 degrees F). The normal monthlyaccumulation is used to schedule single or successive

plantings of a crop between the last freeze in springand the first freeze in fall.

The total annual precipitation is 39.69 inches. Ofthis total, 28.45 inches, or about 72 percent, usuallyfalls in April through October. The growing season formost crops falls within this period. The heaviest 1-dayrainfall during the period of record was 5.84 inches onJune 14, 1950. Thunderstorms occur on about 48 dayseach year, and most occur in June and July.

The average seasonal snowfall is 23.2 inches. Thegreatest snow depth at any one time during the period ofrecord was 21 inches. On the average, 38 days of theyear have at least 1 inch of snow on the ground. Thenumber of such days varies greatly from year to year.

The average relative humidity in midafternoon isabout 61 percent. Humidity is higher at night, and theaverage at dawn is about 83 percent. The sun shines71 percent of the time possible in summer and 48percent in winter. The prevailing wind is from the south.Average windspeed is highest, 12 to 14 miles perhour, from November to April.

19

This section relates the soils in the survey area tothe major factors of soil formation and describes thesystem of soil classification.

Factors of Soil FormationRonald Collman, soil scientist, Natural Resources Conservation

Service, helped prepare this section.

Soil forms through several processes that act ondeposited geologic material. The major factors of soilformation are the physical and mineralogicalcomposition of the parent material; the climate underwhich the soil material has accumulated and existedsince accumulation; the type of living organisms onand in the soil; relief; and the length of time that thesoil-forming factors have acted on the parent material(Fehrenbacher and others, 1968).

Climate and plant and animal life are active factorsof soil formation. They act directly on the parentmaterial that has accumulated in place through theweathering of rocks or that was deposited through theaction of water, wind, or glaciers and slowly change itinto a natural body that has genetically relatedhorizons. Relief also affects the processes of soilformation. It can inhibit soil formation on the steeper,eroded slopes and in wet, depressional or nearly levelareas by controlling the amount of moisture in thesoils. Finally, time is needed to change the parentmaterial into a soil that has distinct horizons.

The factors of soil formation are so closelyinterrelated and conditioned by each other that fewgeneralizations can be made regarding the effects ofany one factor unless conditions are specified for theothers.

Parent Material

Parent materials are determined by the geology ofan area and control the chemical and mineralogicalcomposition of the soil at the beginning of soilformation. Weathering and biological activitiesgradually change the composition of the soil as itdevelops. Parent material includes all organic andinorganic materials that are at the earth’s surface. In

places, old weathered bedrock material and old soilmaterial become parent material for the continuing soildevelopment at the land surface.

Parent materials in Adams County are loess, glacialtill, alluvium, colluvium, eolian sand, Cretaceoussediments, and bedrock residuum.

Loess is windblown silt that was deposited by windsthat carried it from major stream valleys and outwashplains as glacial ice melted. Loess blankets theuplands of Adams County. The texture of the loessbecomes finer with increasing distance from theMississippi River Valley. Loess is relatively young ingeologic terms and covers much of the Midwest. It isthe parent material of many of the soils in the uplandsof Adams County. The loess ranges from 6 to 25 feetin thickness in nearly level areas and is thinner in theeastern part of the county than in the western part.Several soils in the county formed completely in loess;others in the more sloping areas formed in a thin layerof loess and an underlying parent material of differentorigin (fig. 2). Some of the deep loess soils that formedunder forest vegetation are the Stookey and Timulasoils on the bluffs along the Mississippi River and theKeomah, Menfro, Rozetta, and Winfield soils in areasfarther from the bluffs. Deep loess soils that formedunder grass vegetation and that have a dark surfacelayer include the Biggsville soils along the MississippiRiver bluffs and the Edwardsville, Osco, Timewell,Ipava, and Virden soils in areas farther from the bluffs.

Glacial till is a mixture of materials produced byglaciers. The materials range in size from clay tostones. The materials deposited by the ice sheets arefrom distant sources as well as from local sources. InAdams County, tills from the early glacial advancescame from the direction of Iowa and Lake Michigan.Distant sources are indicated by the rocks andminerals that are present, such as granite, quartzite,diorite, galena, and pyrite. Local sources are indicatedby angular chert, limestone, geodes, and shalefragments that were eroded from surroundinglandscapes. The youngest tills in Adams County weredeposited by the Illinoian glacier. These tills are in thenortheastern part of Adams County and arecomposed of materials from northern andnortheastern sources as well as from the materials

Formation and Classification of the Soils

20 Soil Survey of

that were transported by previous glaciers. Hickorysoils occur in moderately steep and steep areaswhere Illinoian till is near the surface. There are atleast two other kinds of till that are older than theIllinoian tills, but they are difficult to distinguish inplaces because their properties and appearance aresimilar to those of the Illinoian tills. These older tills arecollectively called pre-Illinoian till. They are derivedfrom materials from northwestern and northeasternsources as well as from local sources. Lindley soilsoccur where pre-Illinoian tills are near the surface inmoderately steep or steep areas. Pre-Illinoian tills andtheir associated soils may outcrop below Illinoian tillsoils in steep, very dissected areas in the northernpart of Adams County. Paleosols are soils that formedin Illinoian or pre-Illinoian glacial till during aninterglacial period prior to the last glacial advances ofWisconsinan age. Although the Wisconsinan glaciersdid not reach Adams County, the predominant loessdeposits are a result of that last glacial advance. Thestrongly developed paleosols in Adams Countytypically have a very high content of clay. Atlas,Coatsburg, Keswick, and Ursa soils formed in lessthan 20 inches of loess and in the underlying paleosol.

Fishhook and Keller soils formed in 20 to 40 inches ofloess and in the underlying paleosol. In steep and verysteep areas, the paleosol has been eroded and amodern soil has formed in the loess and underlyingglacial till. Hickory and Lindley soils formed in thismaterial.

Alluvium is water-deposited sediment. Streamalluvium, valley-side alluvium, and pedisediment arethe three types of alluvium in Adams County. Streamalluvium consists of well sorted, stratified sedimentson flood plains and stream terraces. The materials thatmake up stream alluvium can be eroded fromanywhere upstream within the watershed.Streambanks in Adams County commonly expose thealluvial history of the stream. Many of the soils in thecounty formed in stream alluvium. Blyton andWakeland soils, for example, formed in silty alluvium,and Sarpy and Zumbro soils formed in sandy alluvium.Because of flooding, many alluvial soils have layers ofcontrasting materials within their profiles. Dupo andRiley soils are examples. Slackwater sediments areincluded as stream alluvium but are deposited in slow-moving or still waters in lakes and sloughs. The soils inthese areas typically have a higher clay content thanthat of the silty or sandy alluvial soils. Titus andBeaucoup soils formed in slackwater sediments.Valley-side alluvium is slopewash or local alluvium onfootslopes and alluvial fans that is derived fromerosion of adjacent sloping areas. The material ispoorly sorted and stratified and reflects the characterof the parent material directly upslope. The largestareas of valley-side alluvial deposits in Adams Countyare along the base of the Mississippi River bluffs.Other areas are throughout the county at the base ofslopes along major streams and their tributaries.Drury, Littleton, and Worthen soils formed in valley-side alluvium. Pedisediment consists of sediments thataccumulated on old erosion surfaces in the uplandsand are now buried by loess deposits. Bunkum,Emery, and Passport soils formed in loess,pedisediment, and the underlying paleosol formed inglacial till.

Colluvium consists of deposits of rock fragmentsand soil material that have accumulated on very steepslopes as a result of gravitational action. Lacrescentsoils formed in limestone colluvial deposits and occuralong the Mississippi River bluffs and major streamsand their tributaries in Adams County.

Eolian sand refers to windblown deposits of finesand. These deposits contain very low percentages ofsand coarser than fine sand and are poorly graded.Sparta soils formed in sandy deposits that werereworked by wind. They are on terraces of the

Figure 2.—Loess overlying glacial drift and limestone bedrock.

Adams County, Illinois—Part I 21

Mississippi River. Lamont soils also formed in sandydeposits. They are in steep and very steep areas nearSiloam Springs State Park.

Cretaceous sediments are stratified marinedeposits that are much older than the glacial depositsof Adams County. They are predominantly deposits ofloose, unconsolidated sand and form a ridge runningfrom near Mendon to the southeast corner of AdamsCounty. Cretaceous sediments include a wide range oftextures from sand to clay. El Dara soils are examples(fig. 3).

Bedrock residuum is the product of directweathering of bedrock. Limestone and shale of theMississippian and Pennsylvanian periods are the twomajor types of bedrock in Adams County (Willman andFrye, 1970). The largest areas of residuum near theland surface occur along the Mississippi River bluffs;along major tributaries, such as Bear Creek, Mill

Creek, and McKee Creek; and in the southern part ofAdams County, where outcrops of bedrock arecommon. Baylis and Crider soils formed in loess andthe underlying limestone residuum. Goss soils formedin limestone residuum. Baylis and Goss soils containcherty gravel. Marseilles soils formed in loess andshale residuum.

Climate

Adams County has a temperate, humid continentalclimate. Although climate has had an important overallinfluence on the characteristics of the soils, it isessentially uniform throughout the county and has notcaused any major differences among the soils.

Climate has a very important effect on weathering,vegetation, and erosion. The weathering of minerals inthe soil increases as temperature and rainfall increase.

Figure 3.—Gullies in an area of El Dara soils, which are typical of soils that formed in Cretaceous deposits.

22 Soil Survey of

As water moves downward, clay is moved from thesurface soil to the subsoil, where it accumulates. Thewater also dissolves soluble salts and leaches themdownward. Climate determines the kind and extent ofplant and animal life on and in the soil. The climate inAdams County has favored prairie grasses andhardwood forests. Heavy rains can harm exposedsoils that are used for crops. Spring rains and windcan cause extensive erosion of the surface if cropresidue and trees are removed. More soil can be lostthrough erosion each year than is formed by naturalprocesses.

Living Organisms

Soil development varies greatly depending on thetype of vegetation in an area. One of the most easilyrecognized examples of the effect of vegetation on soilformation is the difference between prairie soils andforest soils. Under prairie conditions, grasses producea fibrous root system within a few feet of the surface.As they die, these roots contribute to the total contentof organic matter in the surface horizon. Plant materialin the soil breaks down into humus, which retains theminerals, fertilizers, and water added to the soil. Osco,Biggsville, Timewell, Ipava, and Virden soils formedunder prairie vegetation. These soils have a thick,black or dark brown surface layer. Soils that formedunder forest vegetation have a lighter colored surfacelayer than soils that formed under grass. Forestvegetation produces less organic material than prairievegetation, and the organic material accumulates atthe surface. The humus that is produced is more acidthan the humus in areas of grassland. These acidspercolate into the soil and promote the breakdown ofminerals. This process increases the rate of leachingand translocation, which reduces fertility and causesclay-sized particles to accumulate in lower layers. Inareas where this process has been active for a longtime, an eluvial horizon is produced. This horizon hasa bleached or ashy appearance. Keomah, Menfro,Rozetta, Stookey, Timula, and Winfield soils formedunder forest vegetation. Soils that formed under mixedforest and grassland vegetation are called transitionsoils. They are in areas that follow the present prairie-forest border. These soils have a moderately darksurface layer and a moderate content of organicmatter. Mannon, Greenbush, and Clarksdale soils areexamples.

Bacteria, fungi, and other micro-organisms help tobreak down the organic material and thus providenutrients for plants and other soil organisms. The

stability of soil aggregates is affected by microbialactivity. Cellular excretions from these organisms helpto bind soil particles together. Stable aggregates helpto maintain soil porosity and a favorable water-airrelationship in the soil. Earthworms, crayfish, insects,and burrowing animals incorporate organic materialinto the soil and help to maintain porosity.

Human activities, such as clearing of forests,cultivating, applying fertilizers, and draining, haveincreased the hazard of erosion in some areas inAdams County. In other areas, erosion has beencontrolled as a result of human activities. In somesoils, fertility levels have increased. Soil structure hasbeen altered as a result of tillage and compaction.

Relief and Drainage

Depositional and erosional forces have shaped thelandscape in the survey area and created thelandforms that are present today. The relief, or lay ofthe land, and the internal and overland drainagecharacteristics affect soil formation. In general, soilmap unit boundaries follow landform and landformcomponent boundaries. Slopes in the county rangefrom 0 to 60 percent.

The shape and size of the landform play a role inthe development of soils. The shape and slope of alandform affect the depth to the water table andinfluence natural drainage. In nearly level, poorlydrained soils, such as Virden and Rushville soils, thewater table is close to the surface for most of the year.The soil pores contain water, which restricts thecirculation of air in the soil. Under these conditions,iron and manganese compounds are chemicallyreduced. As a result, the subsoil is dull gray andmottled. In areas of the more sloping, well drainedMenfro soils, however, the water table is lower andsome of the rainfall runs off the surface. The soil porescontain less water and more air. The iron andmanganese compounds are well oxidized. As a result,the subsoil is brown and brightly colored.

Nearly level, poorly drained soils, such as Rushvillesoils, are less well developed than the gently sloping,well drained Menfro soils. Rushville soils have a highwater table for part of the year. The wetness inhibitsthe removal of weathered material. In contrast, Menfrosoils are deeper to a water table. As a result,weathered material is translocated downward to agreater extent than in the Rushville soils. Theincreased runoff rate also increases the hazard oferosion and further shapes the landscape. Soils thatformed on the steeper slopes typically have been

Adams County, Illinois—Part I 23

subject to more erosion and less development thansoils in less sloping areas.

Time

The length of time needed for the formation of a soildepends on the other factors of soil formation. Soilsform more rapidly and are more acid if the content oflime in the parent material is low. Soil formationproceeds at a faster rate in rapidly permeable materialthan in slowly permeable material because lime andother soluble minerals are leached more quickly.Prairie soils form less quickly than forest soils becausegrasses are more efficient than trees in recyclingcalcium and other bases from the subsoil to thesurface layer, and thus the loss of exchangeablebases by leaching and the development of soil acidityare slowed. Soils in a humid climate that supportsgood growth of vegetation develop more rapidly thanthose in a dry climate.

The length of time that the parent material has beenin place determines, to a great extent, the degree ofprofile development. Blyton and Wakeland soils are onflood plains. They have a very weakly developedprofile because they periodically receive new alluvialsediments. Although the parent material of Tice soils issimilar to that of the Blyton and Wakeland soils, thesediments in the Tice soils are deposited slowlyenough to allow stronger profile development. Menfroand Osco soils show intermediate profile development.They are in relatively stable upland areas where theparent material has been in place for a long time. Onthe more sloping parts of the landscape, erosion canremove the surface soil material at about the samerate as the rate of soil formation. Thus, soils in theseareas, such Hickory, Lindley, and Timula soils, haveweaker profile development even though the slopeshave been exposed to weathering for thousands ofyears.

Classification of the SoilsThe system of soil classification used by the

National Cooperative Soil Survey has six categories.Beginning with the broadest, these categories are theorder, suborder, great group, subgroup, family, andseries. Classification is based on soil propertiesobserved in the field or inferred from thoseobservations or from laboratory measurements.Table 4 shows the classification of the soils in thesurvey area. The categories are defined in thefollowing paragraphs.

ORDER. Twelve soil orders are recognized. The

differences among orders reflect the dominant soil-forming processes and the degree of soil formation.Each order is identified by a word ending in sol. Anexample is Alfisol.

SUBORDER. Each order is divided into subordersprimarily on the basis of properties that influence soilgenesis and are important to plant growth orproperties that reflect the most important variableswithin the orders. The last syllable in the name of asuborder indicates the order. An example is Udalf (Ud,meaning humid, plus alf, from Alfisol).

GREAT GROUP. Each suborder is divided intogreat groups on the basis of close similarities in kind,arrangement, and degree of development ofpedogenic horizons; soil moisture and temperatureregimes; and base status. Each great group isidentified by the name of a suborder and by a prefixthat indicates a property of the soil. An example isHapludalfs (Hapl, meaning minimal horizonation, plusudalf, the suborder of the Alfisols that has a udicmoisture regime).

SUBGROUP. Each great group has a typicsubgroup. Other subgroups are intergrades orextragrades. The typic is the central concept of thegreat group; it is not necessarily the most extensive.Intergrades are transitions to other orders, suborders,or great groups. Extragrades have some propertiesthat are not representative of the great group but donot indicate transitions to any other known kind of soil.Each subgroup is identified by one or more adjectivespreceding the name of the great group. The adjectiveTypic identifies the subgroup that typifies the greatgroup. An example is Typic Hapludalfs.

FAMILY. Families are established within asubgroup on the basis of physical and chemicalproperties and other characteristics that affectmanagement. Generally, the properties are those ofhorizons below plow depth where there is muchbiological activity. Among the properties andcharacteristics considered are particle-size class,mineral content, temperature regime, thickness of theroot zone, consistence, moisture equivalent, slope,and permanent cracks. A family name consists of thename of a subgroup preceded by terms that indicatesoil properties. An example is fine-silty, mixed, mesicTypic Hapludalfs.

SERIES. The series consists of soils that havesimilar horizons in their profile. The horizons aresimilar in color, texture, structure, reaction,consistence, mineral and chemical composition,and arrangement in the profile. The texture of thesurface layer or of the substratum can differ within aseries.

25

In this section, arranged in alphabetical order, eachsoil series recognized in the survey area is described.Each series description is followed by descriptions ofthe associated detailed soil map units.

Characteristics of the soil and the material in whichit formed are identified for each soil series. A pedon, asmall three-dimensional area of soil, that is typical ofthe series in the survey area is described. The detaileddescription of each soil horizon follows standards inthe “Soil Survey Manual” (Soil Survey Division Staff,1993). Many of the technical terms used in thedescriptions are defined in “Soil Taxonomy” (SoilSurvey Staff, 1999). Unless otherwise stated, colors inthe descriptions are for moist soil. Following the pedondescription is the range of important characteristics ofthe soils in the series.

The map units on the detailed soil maps in thissurvey represent the soils or miscellaneous areas inthe survey area. The map unit descriptions in thissection, along with the maps, can be used todetermine the suitability and potential of a unit forspecific uses. They also can be used to plan themanagement needed for those uses. More informationabout each map unit is given in Part II of this survey.

A map unit delineation on the detailed soil mapsrepresents an area on the landscape and consists ofone or more soils or miscellaneous areas. A map unitis identified and named according to the taxonomicclassification of the dominant soils. Within a taxonomicclass there are precisely defined limits for theproperties of the soils. On the landscape, however, thesoils and miscellaneous areas are naturalphenomena, and they have the characteristicvariability of all natural phenomena. Thus, the range ofsome observed properties may extend beyond thelimits defined for a taxonomic class. Areas of soils of asingle taxonomic class rarely, if ever, can be mappedwithout including areas of other taxonomic classes.Consequently, every map unit is made up of the soilsor miscellaneous areas for which it is named andsome minor components or areas that belong to othertaxonomic classes.

Most map units include some areas with propertiesso similar to those of the dominant soil or soils in themap unit that they do not affect use and management.

These areas are called similar soils. They may or maynot be mentioned in the map unit description. Othersoils and miscellaneous areas, however, haveproperties and behavioral characteristics divergentenough to affect use or to require differentmanagement. These are called dissimilar components.They generally are in small areas and could not bemapped separately because of the scale used. Somesmall areas of strongly contrasting soils ormiscellaneous areas are identified by a special symbolon the maps. The areas of dissimilar soils ormiscellaneous areas are mentioned in the map unitdescriptions. A few of these areas may not have beenobserved, and consequently they are not mentioned inthe descriptions, especially where the pattern was socomplex that it was impractical to make enoughobservations to identify all the soils and miscellaneousareas on the landscape.

The presence of these minor components in a mapunit in no way diminishes the usefulness or accuracyof the data. The objective of mapping is not todelineate pure taxonomic classes but rather toseparate the landscape into segments that havesimilar use and management requirements. Thedelineation of such landscape segments on the mapprovides sufficient information for the development ofresource plans, but if intensive use of small areas isplanned, onsite investigation is needed to define andlocate the soils and miscellaneous areas.

An identifying symbol precedes the map unit namein the map unit descriptions. Each description includesgeneral facts about the unit. The principal hazards andlimitations to be considered in planning for specificuses are described in Part II of this survey.

Soils that have profiles that are almost alike makeup a soil series. Except for differences in texture of thesurface layer or of the underlying layers, all the soils ofa series have major horizons that are similar incomposition, thickness, and arrangement.

Soils of one series can differ in texture of thesurface layer or of the underlying layers. They also candiffer in slope, stoniness, salinity, wetness, degree oferosion, and other characteristics that affect their use.On the basis of such differences, a soil series isdivided into soil phases. Most of the areas shown on

Soil Series and Detailed Soil Map Units

26 Soil Survey of

the detailed soil maps are phases of soil series. Thename of a soil phase commonly indicates a featurethat affects use or management. For example, Menfrosilt loam, 2 to 5 percent slopes, is a phase of theMenfro series.

Some map units are made up of two or more majorsoils or miscellaneous areas. These map units arecalled complexes or undifferentiated groups.

A complex consists of two or more soils ormiscellaneous areas in such an intricate pattern or insuch small areas that they cannot be shownseparately on the maps. The pattern and proportion ofthe soils or miscellaneous areas are somewhat similarin all areas. Blake-Slacwater silt loams, 0 to 2 percentslopes, frequently flooded, long duration, is anexample.

An undifferentiated group is made up of two ormore soils or miscellaneous areas that could bemapped individually but are mapped as one unitbecause similar interpretations can be made for useand management. The pattern and proportion of thesoils or miscellaneous areas in a mapped area are notuniform. An area can be made up of only one of themajor soils or miscellaneous areas, or it can be madeup of all of them. Timewell and Ipava soils, 0 to 2percent slopes, is an undifferentiated group in thissurvey area.

This survey includes miscellaneous areas. Suchareas have little or no soil material and support little orno vegetation. The map unit Pits, quarries, is anexample.

Table 5 gives the acreage and proportionate extentof each map unit. Other tables (see Contents in Part II)give properties of the soils and the limitations,capabilities, and potentials for many uses. TheGlossary defines many of the terms used in describingthe soils or miscellaneous areas.

Atlas Series

Taxonomic classification: Fine, smectitic, mesicAeric Chromic Vertic Epiaqualfs

Typical Pedon for MLRA 115C (OfficialSeries Description)

Atlas silt loam, 5 to 10 percent slopes, eroded, at anelevation of 665 feet; 1,200 feet west and 50 feet southof the northeast corner of sec. 7, T. 1 N., R. 6 W.;USGS Coatsburg, Illinois, topographic quadrangle; lat.40 degrees 5 minutes 39.9 seconds N. and long. 91degrees 7 minutes 51.5 seconds W., NAD 27:

Ap—0 to 7 inches; dark grayish brown (10YR 4/2) siltloam, light brownish gray (10YR 6/2) dry; weak

fine granular structure; friable; common very fineand fine roots; common medium prominent brown(7.5YR 5/8) masses of iron accumulationthroughout, few fine prominent black (2.5Y 2/1)masses of iron and manganese accumulationthroughout, and few fine distinct yellowish brown(10YR 5/6) masses of iron accumulationthroughout; slightly acid; clear smooth boundary.

BE—7 to 13 inches; brown (10YR 5/3) silty clay loam,light brownish gray (10YR 6/2) dry; weak mediumsubangular blocky structure; friable; common fineroots; few fine distinct light brownish gray (10YR6/2) clay depletions and few fine distinct yellowishbrown (10YR 5/6) masses of iron accumulationthroughout; slightly acid; clear wavy boundary.

2Btg1—13 to 26 inches; dark gray (10YR 4/1) siltyclay loam; moderate thick platy structure parting toweak fine subangular blocky; firm; common fineand few medium roots; common distinct very darkgray (10YR 3/1) organo-clay films on faces ofpeds and in pores; few fine prominent yellowishbrown (10YR 5/6) masses of iron accumulationand few fine distinct white (10YR 8/1) masses ofbarite throughout; moderately acid; clear wavyboundary.

2Btg2—26 to 37 inches; 87 percent dark gray (10YR4/1) and 10 percent gray (10YR 5/1) silty clay;weak medium prismatic structure; firm; commonfine and medium roots; few distinct very dark gray(10YR 3/1) organo-clay films on faces of peds andin pores; common fine prominent yellowish brown(10YR 5/6) masses of iron accumulation and fewfine distinct white (10YR 8/1) masses of baritethroughout; 1 percent rounded gravel and 1percent subangular limestone-cherty gravel;neutral; clear wavy boundary.

2Btg3—37 to 47 inches; gray (2.5Y 5/1) silty clay;weak coarse prismatic structure; firm; commonfine roots; few distinct very dark gray (10YR 3/1)organo-clay films on faces of peds and in pores;few fine prominent yellowish brown (10YR 5/6)masses of iron accumulation throughout and fewfine faint gray (10YR 6/1) iron depletions and fewfine distinct white (10YR 8/1) masses of baritethroughout; 1 percent angular gravel; neutral; clearwavy boundary.

2Btg4—47 to 61 inches; gray (2.5Y 5/1) clay loam;weak coarse prismatic structure; firm; commonvery fine roots; few distinct very dark gray (10YR3/1) organo-clay films on faces of peds and inpores; few fine distinct black (2.5Y 2/1) masses ofiron and manganese accumulation and few finedistinct white (10YR 8/1) barite crystalsthroughout; 1 percent limestone-cherty gravel and

Adams County, Illinois—Part I 27

1 percent rounded igneous-granite gravel; neutral;clear wavy boundary.

2BCg—61 to 80 inches; light brownish gray (2.5Y 6/2)clay loam; weak coarse prismatic structure; firm;few fine distinct yellowish brown (10YR 5/6)masses of iron accumulation and commonmedium prominent brownish yellow (10YR 6/8)masses of iron accumulation throughout; 2percent limestone-cherty gravel; neutral.

MLRA Series Range in Characteristics

Thickness of the loess: 0 to 20 inchesDepth to base of diagnostic horizon: More than 42

inchesSlope range: 5 to 10 percent

Ap or A horizon:Hue—10YRValue—2 to 5Chroma—1 to 4Texture—silt loam, loam, silty clay loam, or clay

loam

E or BE horizon:Hue—10YRValue—4 or 5Chroma—1 to 4Texture—silt loam or silty clay loam

Bt, Btg, or 2Btg horizon:Hue—10YR, 2.5Y, 5Y, or NValue—4 to 6Chroma—0 to 3Texture—clay loam, clay, silty clay loam, or silty

clayContent of rock fragments—0 to 5 percent

2Cg horizon (if it occurs):Hue—10YR, 7.5YR, 5Y, or NValue—4 to 6Chroma—0 to 6Texture—silty clay loam, clay loam, or loamContent of rock fragments—2 to 15 percent

7C2—Atlas silt loam, 5 to 10 percentslopes, eroded

Setting

Landform: InterfluvesPosition on the landform: BackslopesType of landscape: Uplands

Soil Properties and Qualities

Drainage class: Somewhat poorly drainedParent material: Paleosol formed in glacial till

Additional information specific to this map unit, suchas horizon depth and textures, is available in the “SoilProperties” section in Part II of this publication.

Composition

Atlas and similar soils: 90 percentDissimilar soils: 10 percent

Similar soils:• Keller soils, which have less clay in the upper part ofthe subsoil than the Atlas soil and have a darkersurface layer• Passport soils, which have less clay in the upperpart of the subsoil than the Atlas soil; in areas upslopefrom the Atlas soil• Severely eroded soils