Table Of ContentUNIVERSITY OF
ILLINOr 18RARY
AT URBANA CHAMPAIGN
ACES
Average Crop,
Pasture,
and
Forestxy
Productivity
for
Ratings
Illinois Soils
CES LIBRARY
UNIVERSITY OF ILLINOIS
1101 S. GOODWIN AVE.
URBANA, IL61801
University ofIllinois
at Urbana-Champaign
College ofAgricultural,Consumer
and Environmental Sciences
Office ofReseai
ILLINOIS
Bulletin810
August2000
University of Illinois
Library at
Urbana-Champaigr
ACES
Bulletin 810
Average Crop, Pasture, and Forestry Productivity Ratings for Illinois Soils
University ofIllinois
College ofAgricultural, Consumer and Environmental Sciences
Office ofResearch
This bulletin wasprepared by K.R. Olson, ProfessorofSoil Conservation, Soil Management and Pedology (NRES);J.M.
Lang,AssociateAgronomist(NRES); J.D. Garcia-Paredes,Agronomy ResearchAssistant; R.N. Majchrzak (Natural
Resources ResearchAssistant); C.I. Hadley (Natural Resources ResearchAssistant); M.E. Woolery (Natural Resources
ResearchAssistant); and R.M. Rejesus (Agricultural andConsumerEconomics ResearchAssociate).
The authorsgratefully acknowledge thecontributions and supportofmembers ofthe Departments ofCrop Sciences
(CS), Natural Resources and Environmental Sciences (NRES), andAgricultural and ConsumerEconomics (ACE);
IllinoisDepartmentofRevenue (IDR); Illinois Farm Bureau (IFB); and Natural Resources Conservation Service
(NRCS), U.S. DepartmentofAgriculture. The authors wishtoacknowledge the contributionsofM. Hodges (USDA-
NRCS), G. Bollero (CS); D.G. Bullock(CS), R.E. Nafziger(CS), G.E. Pepper(CS), R.G. Hoeft (CS),T.R. Peck
(NRES), J.O. Dawson (NRES), R.L. Jones (NRES), R.H. Hornbaker(ACE), S.E. Hollinger(WaterSurvey), andT. Ward
(USDA-NRCS) fortheiradvice andguidance.
Funding forthe project was providedby the Special Research Initiative ofthe Office ofResearch, the Departmentof
Natural Resources and Environmental Sciences, andthe IllinoisDepartmentofRevenue.
Urbana, Illinois August2000
rio.^/o
V
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Contents Page
Introduction .................................................................................................................................................................. 1
Changes from Previous Soil Productivity Publications................................................................................................ 2
Data Sources and Methods ........................................................................................................................................... 3
AverageLevel ofManagement .................................................................................................................................... 4
EstimatedTen-YearAverage CropYields in Illinois UnderanAverage Level ofManagement.................................. 4
CropAdaptation to Various Soils ................................................................................................................................. 4
Relationship BetweenTen-YearAverageYields andAverage Level ofManagement ................................................. 4
SoilType Selection .......................................................................................................................................................24
RegressionAnalysis ofCircular 1156Average CropYields ........................................................................................24
Preliminary StatisticalAnalysis....................................................................................................................................25
Illinois Farm Business Farm Management Records andCropYield Descriptions ......................................................25
Ten-YearAverageCorn, Soybean, andWheatYields ofIllinois Soils UnderanAverage Level ofManagement.......26
Regression ModelingApproach ......................................................................................................26
Illinois Farm Business Farm ManagementApproach .....................................................................28
TestCounty YieldData....................................................................................................................28
Field-MeasuredCorn and SoybeanYields ......................................................................................29
OatYields ofIllinois Soils UnderanAverage Level ofManagement .........................................................................29
Regression ModelingApproach ......................................................................................................29
Illinois Farm Business Farm ManagementApproach .....................................................................29
TestCountyYield Data....................................................................................................................29
Grain SorghumYields ofIllinois Soils UnderanAverageLevel ofManagement.......................................................29
Regression ModelingApproach ......................................................................................................29
Illinois Farm Business Farm ManagementApproach .....................................................................30
Hay and PastureYieldsofIllinois Soils UnderanAverage Level ofManagement .....................................................30
Regression ModelingApproach ......................................................................................................30
IllinoisFarm Business Farm ManagementApproach .....................................................................30
in
TestCountyYield Data 30
Reasons forCropYieldVariability 54
TimberYields ofIllinois Soils UnderanAverage Level ofManagement 54
Crop Productivity Indices ofIllinois Soils UnderanAverage Level ofManagement 55
Calculation ofProductivity Indices forGrain andForageCrops Underan
Average LevelofManagement 56
Adjustments inCropYields andProductivity Indices 57
Adjustments forIncreasing Slope andErosion 58
RelationshipsAmong Soil Prefixes, Soil Numbers, and Soil Names 59
AdjustmentforFlooding 59
Adjustments forSoil Complexes andSoilAssociations 59
Summary 60
References ... ...61
ListofTables
Table 1. GoalsofAverage ManagementLevel 2
Table 2. Productivity ofIllinois SoilsUnderanAverageLevelofManagement, Slightly
0% 2%
Eroded, to Slopes 5
Table 3. SoilTypes (Base andBenchmark) Usedto DevelopCropYieldModels 24
Table4. YieldTrendCoefficients forSoil Regions fromIllinoisAgricultural Statistics (IAS)
forIndividualYears from 1978-1999 andFarmBusinessFarmManagement(FBFM) forIndividualYears
from 1976-1995 26
Table 5. Relationship Between 1990s FarmBusiness FarmManagementRecordCropYields
and Basic Soil Productivity Indicesby Illinois Soil Region 28
Table 6. PastureandTimberRatings ofIllinois Soils, Slightly Eroded, 0% to 2% Slopes 31
Table 7. DecimalAdjustments in CropYields and Productivity Indices UnderanAverage Level ofManagement
forVarious Slope GroupsandErosion Phases 59
ListofFigures
Figure 1A. MovingTen-YearCornYieldTrends inNorthern andSouthern Illinois from 1978 to 1999 77
Figure IB. MovingTen-YearSoybeanYieldTrends in Northern and Southern Illinois from 1978 to 1999 77
IV
Figure 1C. MovingTen-YearWheatYieldTrends in Northern and Southern Illinois from 1978 to 1999 78
Figure ID. MovingTen-YearOat YieldTrends in Northern Illinois from 1978 to 1999 78
Figure IE. MovingTen-YearGrain SorghumYieldTrends in Southern Illinois from 1983 to 1999 79
Figure IF. MovingTen-YearHay (Alfalfaand Grass-Legume)YieldTrends from 1978 to 1999 79
Figure 2. NineTestCounties in the Northern and Southern Soil RegionsofIllinois 80
Figure 3A. Land Use andCropAcreage Distribution in Northern Illinois 80
Figure 3B. Land Use andCropAcreage Distribution in Southern Illinois 80
Figure4A. Relationship BetweenTen-YearAverage CropYields and Productivity Indices
UnderanAverage Level ofManagement 81
Figure4B. Relationship BetweenTen-YearAverage Hay (AlfalfaandGrass-Legume)Yields
and Productivity Indices UnderanAverage Level ofManagement 81
Figure 5. Adjustments inYields and Productivity Indices forVarious Slope Groups andErosion Phases
with Favorable andUnfavorable Subsoils UnderanAverage Level ofManagement 82
ListofAppendices
AppendixA: Alphabetical Listofand Percent Slope Ranges forSoilTypes in Illinois UnderanAverage Level
ofManagement 63
Appendix B: SoilType Characterization Datafor34 Base and Benchmark Soils 72
Appendix C: ListofSoil Types withThree to FiveYearsofMeasuredCorn and SoybeanYields
Underan Optimum Level ofManagement 75
Appendix D: The 70 SoilTypes in Southern Illinois Used toDevelopEquations forTimberSite Indices 76
