Chapter 5
Phosphorus and Potassium
Table 1 • Table
2 • Table 3
Table 1. Soil Test P and K Rating for Peanuts on Coastal Plains
Soils by State Soil Testing Laboratories Using Mehlich-1 Extractant
and North Carolina Which uses the Mehlich-3 Extractant* |
|
Phosphorus (P) |
|
Rating |
AL1 |
FL2 |
GA3 |
SC4 |
VA5 |
NC6 |
|
(Extract) |
(M1) |
(M1) |
(M1) |
(M1) |
(M1) |
(M3) |
|
|
mg P kg-1 |
mg dm-3 |
|
VL |
0 - 6 |
0 - 10 |
-- |
0 - 5 |
-- |
-- |
|
L |
7 - 12 |
11 - 15 |
0 - 15 |
0 - 16 |
0 - 5 |
0 - 30 |
|
M |
13 - 25 |
16 - 30 |
16 - 30 |
6 - 30 |
6 - 17 |
31 - 60 |
|
H |
26 - 50 |
31 - 60 |
31 - 50 |
31 - 60 |
18 - 55 |
61 - 120 |
|
VH |
>50 |
>60 |
>50 |
>60 |
>55 |
>120 |
|
Potassium (K) |
|
Rating |
AL |
FL |
GA |
SC |
VA |
NC |
|
(Extract) |
CEC
<4.6 |
CEC
4.6-9.0 |
(M1) |
(M1) |
(M1) |
(M1) |
(M3) |
|
|
mg P kg-1 |
mg dm-3 |
|
VL |
0-10 |
0-15 |
0 - 20 |
-- |
0 - 12 |
-- |
-- |
|
L |
11-20 |
16-30 |
21 - 35 |
0 - 35 |
13 - 35 |
0 - 37 |
0 - 49 |
|
M |
21-40 |
31-60 |
36 - 60 |
36 - 86 |
36 - 78 |
38 - 87 |
50 - 98 |
|
H |
41-80 |
61-120 |
61 - 125 |
87 - 137 |
79 - 177 |
88 - 155 |
99 - 196 |
|
VH |
>80 |
>120 |
>125 |
>137 |
>177 |
>155 |
>196 |
*Where approriate, M1 (Mehlich-1) values were converted
to mg kg-1 from “pounds per acre” assuming
2 x 106 lb acre-1; NC reports M3 (Mehlich-3)
values as an index based upon mg dm-3.
1Cope et al. 1981. 2Hanlon et al. 1991
3Plank 1989. 4Clemson University Coop.
Ext. Serv. 1982. 5Southern Coop. Ser. Bull. 190 1984.
6Tucker and Rhodes 1987. |
Table 2. Recommendations for P2O5
and K2O Fertilization (in Lb Acre-1) for
Peanuts Based on Soil Test Rating by State
for Coastal Plain Soils |
Soil test
rating |
AL1 |
FL2 |
GA3 |
SC4 |
VA5 |
NC6 |
|
|
lb acre-1 |
Phosphorus
(P) |
P2O5 recommended |
|
VL |
120 |
100 |
-- |
100 |
-- |
-- |
|
L |
80 - 100 |
80 |
80 |
80 |
100 - 200 |
50 - 120 |
|
M |
40 - 50 |
40 |
40 |
40 |
50 - 100 |
0 - 50 |
|
H |
0 |
0 |
0 |
0 |
0 - 50 |
0 |
|
VH |
0 |
0 |
0 |
0 |
0 |
0 |
Potassium
(K) |
K2O recommended |
|
VL |
100 - 120 |
100 |
-- |
80 - 100 |
-- |
-- |
|
L |
80 - 100 |
80 |
80 |
80 - 100 |
80 - 120 |
80 - 150 |
|
M |
40 - 60 |
40 |
40 |
40 - 50 |
0 |
25 - 80 |
|
H |
0 |
0 |
0 |
0 |
0 |
0 - 25 |
|
VH |
0 |
0 |
0 |
0 |
0 |
0 |
|
1Cope et al. 1981. 2Hanlon et al. 1991
3Plank 1989. 4Clemson University Coop.
Ext. Serv. 1982. 5Donohue and Hawkins 1980. 6Tucker
and Rhodes 1987. |
Table 3. Nutrients Removed by Peanuts Compared to Other Crops |
|
Crop |
Yield/acre |
N |
P2O5 |
K2O |
Ca |
|
|
Lb |
|
Peanut pods |
2,000 lb |
80 |
15 |
12 |
3 |
|
Peanut vines |
3,000 lb |
47 |
14 |
38 |
34 |
|
Seed cotton |
1 bale |
32 |
12 |
16 |
2 |
|
Soybeans |
25 bu |
94 |
21 |
37 |
19 |
|
Bermudagrass hay |
1 ton |
50 |
12 |
43 |
4 |
Document Prepared by:
Leigh H. Stribling, lstribli@acesag.auburn.edu
Alabama Agricultural Experiment Station
Auburn University |
