Rates of N-P-KTest
 |
|
The Rates
of N-P-K Test was started the same year the Auburn University
established a public soil testing laboratory to serve farmers
and homeowners. The purpose of this experiment is to provide
on-going soil test calibration and interpretation information
in support of the soil testing program. The experiment
is repeated at 7 locations around Alabama. The experiment
consists of 6 N rates, 4 P rates, 5 Krates, and a "no
lime" treatment replicated 4 times (16 treatments)
on plots that are 21 x 35 feet. Crops evaluated on this
experiment are as follows: |
| 1954 - 1961 |
Cotton |
| 1962 - 1964 |
Corn |
| 1965 - 1969 |
Cotton |
| 1970 - 1972 |
Cotton (residual
fertility*) |
| 1973 - 1975 |
Soybean (peanuts
at Wiregrass Substation) |
| 1976 - 1979 |
Corn |
| 1980 - 1982 |
Sweet sorghum at Sand Mt., Brewton,and Tennessee Valley; Soybean and
canola at Monroeville, Prattville,and Upper Coastal; Peanuts at Wiregrass |
| 1983 - 1985 |
Soybean-canola at Wiregrass |
| 1986 - 1987 |
Grain sorghum (residual fertility*) |
| 1988 - 1990 |
Sweet potatoes residual fertility*) at Brewton, Prattville, and Sand Mt. |
| 1989 - 1991 |
Small grain-tropical corn (residual fertility*) all allocations except Brewton,
Prattville, and Sand Mt. |
| 1992 - 1997 |
Forages (residual fertility*) at Sand Mt. and Upper Coastal Plain; Cotton
(residual fertility*) at other locations |
| 1998 - Present |
Fertilization resumed at all locations. |
| 1998 - Present |
Cotton at Prattville,Tenn Valley and Wiregrass. |
| 1998 - Present |
Hybrid bermudagrass at Sand Mt. and Upper Coastal Plain. |
| 2000 - Present |
Long-leaf pine at Monroeville (no fertilizer); Fallow at Brewton. |
(*Residual fertility = no additional P or K applied to
those particular variable treatments)
Rates of N-P-K
Experiment - Established 1954 Wiregrass, Brewton, Monroeville, Prattville,and Mt., Upper Coastal Plain, Tennessee
Valley
|
|
|
Wiregrass
Plot Nos. |
Soybeans
Before 1986 |
Residual
P & K Since 1986 |
Treatment
No. |
Plot Numbers |
Only* |
N |
P205 |
K20 |
|
N |
P205 |
K20 |
|
-------------------------------------------lb/acre--------------------------------------------------- |
1 |
11 |
20 |
38 |
59 |
2 |
0 |
100 |
100 |
No N |
0 |
100 |
100 |
|
2 |
10 |
27 |
41 |
60 |
3 |
30 |
100 |
100 |
|
30 |
100 |
100 |
3 |
8 |
22 |
47 |
61 |
5 |
60 |
100 |
100 |
|
60 |
100 |
100 |
4 |
2 |
26 |
37 |
49 |
4 |
80 |
100 |
100 |
|
120 |
100 |
100 |
5 |
16 |
32 |
42 |
53 |
11 |
0 |
100 |
100 |
Control |
90 |
100 |
100 |
6 |
15 |
30 |
45 |
51 |
6 |
0 |
100 |
100 |
No S |
150 |
100 |
100 |
7 |
5 |
23 |
35 |
50 |
12 |
0 |
0 |
100 |
No P |
90 |
0 |
100 |
8 |
1 |
28 |
40 |
62 |
14 |
0 |
20 |
100 |
|
90 |
0 |
100 |
9 |
6 |
18 |
36 |
55 |
13 |
0 |
40 |
100 |
|
90 |
0 |
100 |
10 |
4 |
17 |
44 |
64 |
16 |
0 |
60 |
100 |
|
90 |
0 |
100 |
11 |
9 |
19 |
34 |
52 |
7 |
0 |
100 |
0 |
No K |
90 |
100 |
0 |
12 |
12 |
25 |
48 |
54 |
8 |
0 |
100 |
20 |
|
90 |
100 |
0 |
13 |
7 |
31 |
43 |
63 |
9 |
0 |
100 |
40 |
|
90 |
100 |
0 |
14 |
14 |
24 |
33 |
57 |
15 |
0 |
100 |
60 |
|
90 |
100 |
0 |
15 |
15 |
13 |
29 |
46 |
56 |
10 |
0 |
100 |
80 |
90 |
100 |
0 |
16 |
3 |
21 |
39 |
58 |
1 |
0 |
100 |
100 |
No Lime |
90 |
100 |
100 |
16B |
- |
- |
- |
- |
17 |
0 |
100 |
100 |
|
90 |
100 |
100 |
*
Plots at Wiregrass are numbered 1-17A and 1-17B in tow ties.
**N rates have varied due
to crop and location.
Recent cropping history:
1983-1985 soybeans (Peanuts at W.G.) /rape; 1980-82 sweet sorghum;
1976-79 corn; 1973-75 soybeans; 1970-72 cotton residual.
Long-term yield records have been
published in:
Cope, J.T. 1984. Long-term
fertilityexperiments
on cotton, corn, soybeans, sorghum, and peanuts, 1929-1982.
Ala. Agric. Exp. Stn. Bul 561. Auburn University, AL.
What's Old is New Again - Historical
Fertility Research Helping Establish Modern Cotton Management Strategies
Highlights
Revised 02/04 |
