Morrow Plots

This experiment has been added by the GLTEN Curators using existing published sources.
Objective
Long-term study of corn.
Description
Established in 1876, the Morrow Plots, also called the Soil Experimentation Fields, are the oldest agricultural research fields in the United States and second oldest in the world, predated only by the Rothamsted Field in England in 1843. Named for George E. Morrow, the Chair of the Agriculture Department in 1876, the Morrow Plots started out as 10 numbered half-acre plots. Only three of the plots remain today: Numbers 3, 4, and 5. Two plots were used for the Observatory in 1895 and 5 plots were seeded back to lawn in 1903. The East side of Undergrad Library now sits where the plots once were. Plot 3 grows corn every year, while the other two plots are on rotations. Research on the plots was instrumental in gaining knowledge on crop rotation, soil nutrient depletion, and the effects of synthetic and natural fertilizers. With crops being consistently grown in the same place for well over 100 years, research and records on the Morrow Plots continue to provide valuable information for a variety of topics, including soil carbon sequestration and long-term effects of fertilizers on soil bacteria. Corn, wheat, soybeans and other crops are still grown on the plots to this day. Soil samples have been collected regularly throughout the experiment.
Data Access Statement
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Data license
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Data policy
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Organization
Crop Sciences Research and Education Center, University of Illinois
research organisation
People

Site: Morrow Plots

Type
research station field
Location
University of Illinois at Urbana-Champaign
Illinois
United States of America
Geographic location
40.104447, -88.225819
© OpenStreetMap contributors
Elevation
229 Metres
Visits permitted?
No
Soil description
The soil is Flanagan silt loam (fine, smectitic, mesic Aquic Argiudolls), which is a nearly level, dark-colored soil that developed in 1 to 1.5 m of loess over loam glacial till under prairie vegetation and somewhat poor natural drainage.

Design period: Phase 1 (1876—1903)

Design description
When originally established in 1876, the Morrow Plots consisted of 10 0.2-ha (one-half acre) plots (Hopkins et al., 1908). Of these, only parts of three remain: plots 3, 4, and 5. The only treatment factor was crop rotation.
Number of plots
10
Number of harvests per year
1
Crops
CropYears grown
maize 1876—
oats
feed legumes
Crop Rotations
continuous maize  1876—1903
  • 1
    maize
M-O  1876—1903
  • 1
    maize
  • 2
    oats
M-O-H  1876—1903
  • 1
    maize
  • 2
    oats
  • 3
    feed legumes
    For hay
Measurement
VariableMaterialUnitsFrequencyScaleComment
grain yield traitAll crops

Design period: Phase 2 (1904—1954)

Description
Crop residues were removed from all plots.
Design description
Plots 3, 4, and 5 survived, but reduced in area to 1/5 acre plots. Each plot carried one of the rotation treatments; the experiment was not fully phased. The plots were split into four plots, NW, NE, SW and SE. NW and NE plots were unamended, SW and SE received manure, lime and phosphorous. The North plots did not receive any inputs.
Number of plots
3
Number of subplots
12
Number of harvests per year
1
Crops
CropYears grown
maize
oats
red clover
Crop Rotations
Continuous Wheat  1904—1954
  • 1
    maize
M-O  1904—1954
  • 1
    maize
  • 2
    oats
M-O-H  1904—1954
  • 1
    maize
  • 2
    oats
  • 3
    red clover
    for hay
Factors
Factor name
Factor levels
farmyard manure exposure
farmyard manure  (4.5 t/ha)
Applied to SW and SE plots.
phosphate fertilizer exposure
rock phosphate
1904—1919
Applied to SW plots
bone meal
1904—1919
Applied to SE plots
triple superphosphate
1920—1954
Chemical form: triple superphosphate
Applied to SW and SE plots
liming exposure
lime
Chemical form: limestone
Applied to SW and SE plots as necessary to adjust pH
Factor combinations
U  1904—1954
Both N plots for each rotation
M with LrP  1904—1919
SW plot for each rotation
farmyard manure exposure: farmyard manure
phosphate fertilizer exposure: rock phosphate
liming exposure: lime
M with LbP  1904—1919
SE plot for each rotation
farmyard manure exposure: farmyard manure
phosphate fertilizer exposure: bone meal
liming exposure: lime
M with LPS  1920—1954
Both S plots for each rotation. Replaced previous rock phosphate and bone meal treatments.
farmyard manure exposure: farmyard manure
phosphate fertilizer exposure: triple superphosphate
liming exposure: lime
Measurement
VariableMaterialUnitsFrequencyScaleComment
grain yield traitAll crops

Design period: Phase 3 (1955—1966)

Description
The experiment was modified to introduce commercial NPK fertilizers to bring the experiment in line with contemporary agronomic practices. This change meant the experiment could be used to determine whether and how fast soil fertility could be restored to depleted land. Plot residues were returned on the NPK plots, but removed as before for all other plots.
Design description
The sub-plots were each split in half to provide 8 sub-sub-plots per rotation plot. West sub-sub plots were named A and B and East sub-sub plots were named C and D.
Number of plots
3
Number of subplots
24
Number of harvests per year
1
Crops
CropYears grown
maize
oats
red clover
Crop Rotations
Continuous maize  1955—1966
  • 1
    maize
M-O  1955—1966
  • 1
    maize
  • 2
    oats
M-O-H  1955—1966
  • 1
    maize
  • 2
    oats
  • 3
    red clover
    For hay
Factors
Factor name
Factor levels
farmyard manure exposure
farmyard manure  (4.5 t/ha)
Applied to S plots
NPK fertilizer exposure
NPK  (224 kgN/ha)
Chemical form: urea
Applied to B sub-sub plots. Plot residues were returned for these plots.
seeding rate
High rate
Applied to S-C sub-sub plots.
Factor combinations
U
No inputs, all N-A, N-C and N-D plots for each rotation
U-NPK
All N-B plots for each rotation
NPK fertilizer exposure: NPK
M
All S-A and S-D plots for each rotation
farmyard manure exposure: farmyard manure
M-NPK
All S-B plots for each rotation
farmyard manure exposure: farmyard manure
NPK fertilizer exposure: NPK
MPS
All S-C plots for each rotation
farmyard manure exposure: farmyard manure
seeding rate: High rate

Design period: Phase 4 (1967—1996)

Design description
The plots and treatments were unchanged for this phase except for a higher rate N treatment (336 kg N ha-1) was applied to S-A plots in each rotation (this replaced manure treatments previously applied). Soybean replaced oats in the W-O rotation
Number of plots
3
Number of subplots
24
Number of harvests per year
1
Crops
CropYears grown
maize
soybeans
red clover
oats
Crop Rotations
Continuous maize
  • 1
    maize
M-SB
  • 1
    maize
  • 2
    soybeans
M-O-H
  • 1
    maize
  • 2
    oats
  • 3
    red clover
    For hay
Measurement
VariableMaterialUnitsFrequencyScaleComment
grain yield traitAll crops

Design period: Phase 5 (1997—)

Description
In 1998 plot tillage was changed from a moldboard plough to a twisted shank chisel plough operating at 30-40 cm depth. This was about twice as deep as the moldboard plough and better reflected modern tillage practices.
Design description
The plots, rotations and treatments were unchanged for this phase except for the higher N rate applied to the S-A plots was replaced with the lower N rate applied to the B plots.
Number of plots
3
Number of subplots
24
Number of harvests per year
1
Crops
CropYears grown
maize
oats
soybeans
red clover
Measurement
VariableMaterialUnitsFrequencyScaleComment
grain yield traitAll crops

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