"Two-Year Rotation" (c. 1929)
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The "Two-Year
Rotation" was one of the first experiments established
after the Alabama Agricultural Experimentation Station began
in 1928 and the only one to survive. It is a soil fertility
experiment with 17 variables replicated 4 times (2 replications
per crop each year). Variables include 4 N rates, 3 P rates,
4 K rates, 2 lime/pH levels,a "no S"treatment, a "+
micronutrient" treatment, an"untreated" control,
and a treatment that was untreated until 1979. Crops have changed
as the need for soil fertility information on different crops
evolved, but it has always been in a two-year rotation with
2 of the 4 replicates planted to different crops. This same
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experiment is at 6 Alabama locations. Today, the
Two-Year Rotation is used primarily for soil test calibration
research and as a source of soil and plant material for allied studies.
1929 - 1967 |
Cotton (winter
legumes)-corn (winter legumes) |
1968 - 1978 |
Corn-winter wheat-soybean |
1979 - 1981 |
Corn-soybean* |
1982 - 1988 |
Grain sorghum-soybean* |
1989 - 1991 |
Soybean*-winter
wheat-tropical corn |
1992 - present |
Cotton-soybean*
(Prattville, Tenn Valley, Wiregrass) |
2002 - Present |
Longleaf pine
(Monroeville) Fallow Brewton |
1992 - present |
Forages (Sand
Mountain) |
* Peanuts substituted for soybeans
at Wiregrass Substation only
Two-Year Rotation
Established 1928
Wiregrass, Brewton,
Monroeville,
Prattville, Sand Mt., Tennessee Valley
Treatment and Plot No.
|
Corn Before 1982 |
Cotton Residual Soybeans
or Peanuts since 1982-1998 |
Cotton - Soybeans or Peanuts
1998 - Present |
| |
|
N |
P205 |
K20 |
N |
P205 |
K20 |
N |
P205 |
K20 |
|
1 |
Untreated |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
2 |
No S |
120 |
60 |
60 |
150/0 |
0 |
0 |
150 |
60 |
60 |
3 |
|
120 |
30 |
60 |
90/0 |
0 |
0 |
90 |
30 |
60 |
4 |
No Lime |
120 |
60 |
60 |
90/0 |
0 |
0 |
90 |
60 |
60 |
5 |
No Mg(Calcitic Lime) |
120 |
60 |
60 |
90/0 |
0 |
0 |
90 |
60 |
60 |
6 |
No K |
120 |
60 |
0 |
90/0 |
0 |
0 |
90 |
60 |
0 |
7 |
|
120 |
60 |
30 |
90/0 |
0 |
0 |
90 |
60 |
30 |
8 |
+ micros |
120 |
60 |
60 |
90/0 |
0 |
0 |
90 |
60 |
60 |
9 |
No N-P-K |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
10 |
High N |
150 |
60 |
60 |
120/0 |
0 |
0 |
120 |
60 |
60 |
11 |
|
90 |
60 |
60 |
30/0 |
0 |
0 |
30 |
60 |
60 |
12 |
No P |
120 |
0 |
60 |
90/0 |
0 |
0 |
90 |
0 |
60 |
13 |
|
120 |
60 |
60 |
60/0 |
0 |
0 |
60 |
60 |
60 |
14 |
Control |
120 |
60 |
60 |
90/0 |
60 |
60 |
90 |
60 |
60 |
15 |
|
120 |
60 |
120 |
90/0 |
0 |
0 |
90 |
60 |
120 |
16 |
No N |
0 |
60 |
60 |
0 |
0 |
0 |
0 |
60 |
80 |
17 |
Rejuvenation |
120 |
120 |
120 |
90/0 |
0 |
0 |
0 |
0 |
0 |
* N Applied
to grain sorghum in rotation with soybeans. No N applied to soybeans.
Recent
cropping history: 1982-present soybeans (peanuts at W.G.)/grain
sorghum; 1979-1981 soybeans/corn; 1968-78 wheat/soybeans/corn;
1959-67 cotton/corn
Cotton 1998 - Present
Fertilizer treatments to be used
in 1998 revision of "Rates
of N-P-K Test" at 5 locations.
Treatment
number
BEF, MEF, PEF, TV |
WSG Only |
Soil Fertility Factor Studied |
Fertility
variable
|
| N |
P205 |
K20 |
-------------------------1lb/acre------------------------- |
|
1 |
2 |
No N |
0 |
100 |
100 |
2 |
3 |
Low N Rate |
30 |
100 |
100 |
3 |
5 |
Intermediate N Rate |
60 |
100 |
100 |
4 |
4 |
High N Rate |
120 |
100 |
100 |
5 |
11 |
Control |
90 |
100 |
100 |
6 |
6 |
No S/Very high N |
150 |
100 |
100 |
7 |
12 |
No P (very low Soil
P) |
90 |
0 |
100 |
8 |
14 |
Very low soil P |
90 |
20 |
100 |
9 |
13 |
Low soil P |
90 |
40 |
100 |
10 |
16 |
Intermediate soil P |
90 |
60 |
100 |
11 |
7 |
No K (very low soil
K) |
90 |
100 |
0 |
12 |
8 |
Very low residual soil
K |
90 |
100 |
20 |
13 |
9 |
Low residual soil K |
90 |
100 |
40 |
14 |
15 |
intermiediate Soil
K |
90 |
100 |
60 |
15 |
10 |
High residual soil
K |
90 |
100 |
80 |
16 |
1 |
NO LIME |
90 |
100 |
100 |
16B |
17 |
NO LIME/NOTHING |
0 |
0 |
0 |
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Cotton at Brewton Experiment Field
before 2002
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Severe K deficiency
of cotton on the "no
K" treatment at Prattville Experiment Field |
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Potassium deficiency of soybean
at Sand Mountain Substation on "no K" treatment before
1991. |
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Cotton on "no K" treatment
on the Two-Year Rotation Experiment at Prattville
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Long-term yield records have been published
in:
Cope, J.T. 1984. Long-term fertility
experiments on cotton, corn, soybeans, sorghum, and peanuts,
1929-1982. Ala. Agric. Exp. Stn. Bul 561. Auburn University,
AL.
See some links on "Rate
of N-P-K Test.
- What's Old is New Again - Historical
Fertility Research Helping Establish Modern Cotton Management
Strategies Highlights
Revised 09/02
