DEPARTMENT OF AGRONOMY & SOILS
AGRICULTURAL EXPERIMENT STATION
R. DENNIS ROUSE, Director FEBRUARY 1976
DEPARTMENTAL SERIES NO. 28
AUBURN UNIVERSITY
AUBURN, ALABAMA
ALABAMA
SOIL TEST
SUMMARY
for 1975
1 -~ --
FIRST PRINTING 1 /2M, FEBRUARY 1976
Auburn University is an equal opportunity employer
CONTENTS
Page
SOIL TEST RATINGS FOR PHOSPHORUS, POTASSIUM, AND MAGNESIUM: 4
Ratings by Soil Groups-- - -- - - - - -- -- - - - - - - - - - - - 4
R atin g s b y C rop s- - - - - - - - - - - - - - - - -- - - - - - - - - - - - -- - - - - - -- - - - - - - 4
SOIL PH D ISTRIBUTION -------------------------------------------- 6
Distribution Among Soil Groups ___________----------------------6
D istribution Am ong Crops --------------------------------------- 7
FERTILIZER GRADES RECOMMENDED FOR THE DIFFERENT SOIL GROUPS----8
FERTILIZER GRADES RECOMMENDED FOR THE DIFFERENT CROPS --------- 9
CALCIUM RATINGS OF SAMPLES FOR PEANUTS FROM 18 COUNTIES .______10
ALABAMA SOIL TEST
SUMMARY FOR 1975
DAN L. KIRKLAND and J. T. COPE*
The Auburn University Soil Testing Program is a joint
effort of the Agricultural Experiment Station and the Ala-
bama Cooperative Extension Service. The Extension Serv-
ice distributes soil test supplies and provides educational
and promotional services to residents throughout the state.
The Experiment Station operates the laboratory and con-
ducts fertility research on substations, experiment fields,
and on fields of cooperating farmers to obtain information
on which to base fertilizer and lime recommendations
made by the laboratory.
Soil test results and recommendations are recorded by
the computer throughout each fiscal year, July 1 through
June 30. At the year's end, they are summarized to show
the many relationships among soil test values, soil groups,
and crops to be grown for each county and for the entire
State. The most recent state summary published was in
Agronomy and Soils Departmental Series No. 15 for 1972
and 1978. The present publication includes data from
59,508 samples analyzed from July 1, 1974 through June
80, 1975. These data are quite similar to those from
47,000 samples analyzed in 1973-74.
The laboratory has been in operation for 23 years. The
graph on the cover indicates the cumulative total and
projects the anticipated number of samples for the next 7
years. During the first 15 years one-quarter of a million
samples were tested. Seven years later, the second quarter
million mark was reached. If samples continue at the
present rate, one million will be reached in 1982. If the
number of samples continues to increase as it has in the
past 2 years, the million sample mark will be reached
much sooner. The millionth sample has no particular sig-
nificance; however, the increasing numbers indicate the
acceptance and success of the program.
The reasons for the recent increase in interest in soil
testing probably include fertilizer prices, increased home
gardening, and shifts in cropping patterns such as has
occurred with cotton between Districts II and I. It may
also indicate that the public is more aware of the service
available and has more confidence in the information ob-
tained.
The computerized program used by the laboratory pro-
vides a summary of several types of information about the
samples received. This summary indicates the interest in
the program in the various areas of the State. It allows
for the identification of crops produced, the soil fertility
problems most frequently encountered and the kinds and
amount of fertilizer and lime needed to correct the fer-
tility problems indicated by the soil tests.
The importance of homeowner samples is indicated by
the fact that three of the ten leading counties in 1975
were Jefferson, Mobile, and Montgomery as shown in
Table 1. All of the other top ten were in extension dis-
tricts I and II, which include the principle row crop areas
in the State.
TABLE 1. THE RELATIVE RANK OF THE LEADING COUNTIES IN NUMBER OF SOIL SAMPLES SUBMITTED
Rank 1953-1967 1968-1972 1973 1974 1975
1 Houston Jefferson Jefferson Jefferson Houston
2 Geneva Montgomery Houston Houston Jefferson
3 Limestone Houston Coffee Coffee Coffee
4 Coffee Pike Pike Henry Geneva
5 Barbour Dallas Dallas Pike Henry
6 Pike Henry Geneva Dallas Madison
7 Madison Madison Henry Montgomery Barbour
8 Montgomery Coffee Mobile Geneva Mobile
9 Jefferson Geneva Montgomery Madison Covington
10 Morgan Lee Lee Mobile Montgomery
11 Barbour Pike
12 Autauga Dallas
* Research Associate and Professor, Department of Agronomy and Soils.
[3]
Thousands of
soil samples
200
190-
180-
170-
160-
150-
140
130
120 -
100
90-
80-
40-
30
20-
10-
I I I I I
1967 1972 1973 1974 1975
Years
FIG. Cumulative number of samples received from each district.
Participation in soil testing is greatest in the Wiregrass
area in District II, as shown in the figure. Thirty-seven
percent of all soil samples received in 1975 were from
this district. Thirty-six percent of the cumulative 23-year
total have come from this peanut producing area. The
number received from District I (Tennessee Valley) is in-
creasing at a rate that almost parallels the increase shown
in District II in the last 2 years. Twenty-seven percent
of all samples received in 1975 were from District II,
while the cumulative percentage for 23 years is 24 per-
cent. These two districts together have submitted 60 per-
cent of all samples, while in 1975 they submitted 64
percent. Tables 2-5 give the cumulative number of sam-
ples from each district for the past 23 years.
SOIL-TEST RATINGS FOR PHOSPHORUS,
POTASSIUM, AND MAGNESIUM
Ratings by Soil Groups
Response to fertilizers and lime varies among soils.
The amount and kind of clay and the amount of organic
matter in soils are the principal factors that cause soils to
vary in their response. When soil samples are received
in the laboratory, they are classified into five soil groups.
These groups may be briefly described as follows:
Group
1
2
3
4
5
Brief description
Sandy soils of the Coastal Plain
Loams and light clays
Clay soils of the Black Belt
Sandy loams of North Alabama
Red clays of the Limestone Valleys
Cation exchange
capacity*
Meq/100 g
Less than 5
5 to 10
More than 15
5 to 10
10 to 15
* The cation exchange capacity is determined by the clay
and organic matter content.
The number and percentage of samples as rated for
P, K, and Mg are presented in Table 6. Only those sam-
ples rated Very Low, Low, or Medium can be expected
to respond to fertilizer. Samples rated High or Very High
have adequate amounts of the nutrient rated to produce
top yields without addition of the element and none is
recommended. Where none is applied, soils should be
sampled each year to prevent any loss in yield.
The P ratings show the influence of past fertilizer ap-
plications in building up soil P on many soils. Over half
(51 percent) of all samples were H, VH, or EH in P,
compared to 50 percent in 1974 and 52 percent in 1973.
Soil groups 1, 2, and 4 were close to this average, while
of the Black Belt clayey soils of Group 3, 75 percent
would be expected to respond to P. Over 60 percent of
the red clayey soils of the Tennessee Valley were H or VH
in P.
The ratings for K show that 57 percent of all samples
were VL, L, or M and would be expected to respond.
Groups 1, 2, and 5 are near the State average while of
the Sand Mountain soils in Group 4, 65 percent would be
expected to respond to K. Only 47 percent of the Black
Belt soils of Group 3 needed K.
Based on anticipated response to Mg (magnesium),
soils are divided into only two groups, Low and High.
Only 16 percent of samples were low. Most of these were
the sandy soils of the coastal plain and the Sand Moun-
tain area of Northeast Alabama. Many crops have not
shown a need for added Mg on Alabama soils. On all crops,
however, dolomite is recommended when Mg is low, and
lime is needed. Of Group 4 soils, 40 percent was low in
Mg; Group 1, 18 percent, and Group 5 the lowest at 2
percent. Groups 2 and 3 were intermediate at 11 and 8
percent.
The varying proportions of responsive soils in the groups
indicate that fertilizer needs will vary considerably from
one soil area to another, a fact that is widely recognized.
The State cannot be considered to be a uniform market
area. Fertilizer materials should be mixed to meet the
needs of the area. The summary offers an insight into
the combinations of P and K that are needed in the State.
Ratings by Crops
Crops vary in their requirements for P, K, and Mg.
Soils are rated based on the crop to be grown, and fer-
tilizer recommendations are based on these ratings. Soils
rated VL will produce less than 50 percent of their po-
tential if the element is not applied. Low soils should
yield 50 to 75 percent of maximum and M soils 75 to
100 percent. High soils have adequate P or K to produce
top yields, while VH indicates that the soil contains more
than twice the amount needed. Extremely High soils have
more than four times the amount needed and further
additions may be detrimental.
[4]
TABLE 2. NUMBER OF SAMPLES RECEIVED AND PERCENT OF STATE TOTAL BY COUNTY AND
BY DISTRICT, JULY 1, 1974 THROUGH JUNE 30, 1975-DISTRICT 1
1953-67 1968-72 1973 1974 1975 23 years
Number Pct. Number PCt. Number PCt. Number Pct. Number PCt. Number Pct.
Blount____________________ 2,508 1.0 1,736 1.2 352 1.1 744 1.6 912 1.5 6,247 1.2
Cherokee ---------------- 3,833 1.5 1,839 1.3 423 1.3 395 0.8 1,042 1.8 7,532 1.4
Colbert ------------------- 2,428 1.0 1,384 0.9 302 0.9 653 1.4 798 1.3 5,565 1.0
Cullman ----------------- 3,214 1.3 1,766 1.2 538 1.6 023 1.3 888 1.5 7,029 1.3
DeKalb .______________ 5,096 2.0 2,580 1.8 444 1.3 906 1.9 1,141 1.9 10,167 1.9
Etowah ------------------- 2,508 1.0 2,028 1.4 303 0.9 493 1.0 824 1.4 6,156 1.1
Franklin__________________ 3,078 1.2 1,288 0.9 159 0.5 241 0.5 615 1.0 5,381 1.0
Jackson -------------- 2,943 1.2 1,842 1.3 446 1.4 933 2.0 1,012 1.7 7,176 1.3
Lauderdale_____________ 6,706 2.3 2,909 2.0 618 1.9 814 1.7 972 1.6 12,019 2.2
Lawrence_____________ 2,025 0.8 1,413 1.0 383 1.2 618 1.3 1,214 2.0 5,653 1.0
Limestone_______________ 10,247 4.1 2,375 1.6 702 2.1 783 1.7 1,171 2.0 15,278 2.8
Madison_________________ 6,979 2.8 4,192 2.9 769 2.3 1,330 2.8 1,641 2.8 14,911 2.8
Marion --------------------- 1,678 0.7 1,119 0.8 199 0.6 321 0.7 461 0.8 3,778 0.7
Marshall ---------------- 3,170 1.3 1,503 1.0 389 1.2 820 1.7 1,151 1.9 7,033 1.3
Morgan ------------------ 6,369 2.5 2,476 1.7 444 1.3 675 1.4 1,279 2.1 11,243 2.1
Winston__________________ 888 0.4 713 0.5 191 0.6 212 0.5 381 0.6 2,385 0.4
District total---------- 63,665 25.2 31,163 21.2 6,662 20.2 10,561 22.5 15,502 26.1 127,553 
23.7
State total --------------- 252,815 100.0 146,834 100.0 32,942 100.0 46,963 100.0 59,503 100.0 539,057 100.0
TABLE 3. NUMBER OF SAMPLES RECEIVED AND PERCENT OF STATE TOTAL BY COUNTY AND
BY DISTRICT, JULY 1, 1974 THROUGH JUNE 30, 1975--DISTRICT 2
County 1953-67 
1968-72 
1973 1974 
1975 23 years
Number Pct. Number Pct. Number Pct. Number Pct. Number Pct. Number Pct.
Barbour ------------------ 9,029 3.6 3,110 2.1 727 2.2 1,193 2.5 1,582 2.7 15,639 2.9
Bullock ------------------- 3,131 1.2 1,827 1.2 291 0.9 467 1.0 731 1.2 6,447 1.2
Chambers ------------ 1,758 0.7 1,697 1.2 337 1.0 330 0.7 591 1.0 4,713 0.9
Coffee --------------------- 8,982 3.6 4,107 2.8 1,262 3.8 1,718 3.7 2,240 3.8 18,309 3.4
Coosa --------------------- 765 0.3 443 0.3 62 0.2 155 0.3 144 0.2 1,569 0.3
Covington___________ 6,148 2.4 3,158 2.2 611 1.9 1,020 2.2 1,467 2.5 12,404 2.3
Creushaw______________ 2,977 1.2 1,720 1.2 438 1.3 713 1.5 842 1.4 6,690 1.2
Dale____________________ _-- 5,590 2.2 2,477 1.7 669 2.0 802 1.7 1,248 2.1 10,786 2.0
Elmore____________________ 4,484 1.8 2,414 1.6 440 1.3 611 1.3 877 1.5 8,826 1.6
Geneva ------------------- 10,639 4.2 4,053 2.8 1,166 3.5 1,334 2.8 2,117 3.6 19,309 3.6
Henry---------------------- 8,50'1 3.4 4,672 3.2 1,154 3.5 1,525 3.2 2,021 3.4 17,873 3.3
Houston ------------------- 11,503 4.5 5,495 3.7 1,488 4.5 2,314 4.9 3,706 6.2 24,506 4.5
Lee__________________________ 5,170 2.0 3,893 2.7 840 2.5 968 2.1 1,120 1.9 11,991 2.2
Macon -------------------- 3,154 1.2 2,544 1.7 481 1.5 685 1.5 688 1.2 7,552 1.4
Pike_________________________ 8,179 3.2 5,178 3.5 1,256 3.8 1,486 3.2 1,392 2.3 17,491 3.2
Russell ____________________ 2,097 0.8 1,427 1.0 349 1.1 470 1.0 551 0.9 4,894 0.9
Tallapoosa -------------- 2,512 1.0 1,026 0.7 244 0.7 454 1.0 319 0.5 4,555 0.8
District total ----------- 94,619 37.4 49,241 33.5 11,815 35.9 16,245 34.6 21,634 36.4 193,554 35.9
State total - -252,851 100.0 146,834 100.0 32,942 100.0 46,963 100.0 59,503 100.0 539,057 100.0
TABLE 4. NUMBER OF SAMPLES RECEIVED AND PERCENT OF STATE TOTAL BY COUNTY AND
BY DISTRICT, JULY 1, 1974 THROUGH JUNE 30, 1975-DISTRICT 3
Cony1953-67 1968-72 
1973 1974 1975 
23 years
Cony Number Pct. Number Pct. Number Pct. Number Pct. Number Pct. Number Pct.
Baldwin_________ 4,132 1.6 3,535 2.4 673 2.0 838 1.8 1,023 1.7 10,201 1.9
Butler ----------- 3,084 1.2 872 0.6 185 0.6 353 0.8 302 0.5 4,796 0.9
Choctaw --------- 1,516 0.6 1,145 0.8 179 0.5 302 0.6 287 0.5 3,429 0.6
[ 5]1
TABLE 5. NUMBER OF SAMPLES REcEIVED AND PERCENT OF STATE TOTAL BY COUNTY AND
BY DISTRICT, JULY 1, 1974 THROUGH JUNE 10, 1975-DISTRICT 4
1953-67 1968-72 1973 1974 1975 23 years
Number Pet. Number Pet. Number Pet. Number Pet. Number Pet. Number 
Pet.
4,251
1,862
2,585
1,933
1,285
899
1,917
2,654
6,500
2,595
2,141
1,372
2,786
1,937
2,346
4,398
1,441
1.7
0.7
1.0
0.8
0.5
0.4
0.8
1.0
2.6
1.0
0.8
0.5
1.1
0.8
0.9
1.7
0.6
3,577
1,060
1,563
1,603
906
620
841
1,623
6,527
1,064
1,291
882
1,321
1,369
1,479
3,296
1,260
2.4
0.7
1.1
1.1
0.6
0.4
0.6
1.1
4.4
0.7
0.9
0.6
0.9
0.9
1.0
2.2
0.9
897
246
394
529
90
83
196
328
1,583
147
248
175
209
220
401
691
272
2.7
0.7
1.2
1.6
0.3
0.3
0.6
1.0
4.8
0.4
0.8
0.S
0.6
0.7
1.2
2.1
0.8
1,186
424
517
504
203
126
181
444
2,494
426
468
228
421
420
529
885
357
2.5
0.9
1.1
1.1
0.4
0.3
0.4
0.9
5.3
0.9
1.0.
0.5
0.9
0.9
1.1
1.9
0.8
1,001
284
648
690
169
157
271
401
2,610
372
498
323
728
522
549
1,218
440
1.7
0.5
1.1
1.2
0.3
0.3
0.5
0.7
4.4
0.6
0.8
0.5
1.2
0.9
0.9
2.0
0.7
10,912
3,876
5,70 7
5,259
2,653
1,885
3,406
5,450
19,714
4,604
4,646
2,80
5,465
4,468
5,304
10,488
3,770
2.0
0.7
1.1
1.0
0.5
0.3
0.6
1.0
3.7
0.9
0.9
0.6
1.0
0.8
1.0
1.9
0.7
District total ._________ 02 17.0
Stato total________ 252,815 100.0
30,282 20.6
146,834 100.0
6,709 20.4 9,813 20.9
32,942 100.0 46,963 100.0
10,881 18.3
59,503 100.0
100,587 18.7
539,057 100.0
A summary of ratings by crops is presented in Table 7.
Ratings for field crops and horticultural crops are sum-
marized separately in the last four lines of the table. In
September 1974, recommendations were changed so that
P and K are no longer recommended for field and forage
crops testing H. Thus only 57 percent of these samples
would have received a P recommendation in 1975. Even
though a recommendation of a maintenance application
for horticultural crops is continued at H, only 47 percent
would get a P recommendation because 53 percent of
these samples were VH or EH. Percentages needing P
for the various crops can be calculated from data in the
table. As an example, 66 percent of samples for cotton
were H, VH, or EH in P and would not get a P recom-
mendation.
The summary of K data for field crops shows that 57
percent of samples were VL, L, or M and needed K fer-
tilization. The remaining 43 percent were H or VH. For
horticultural crops, 91 percent needed K since only the 9
percent that were VH would not get a K recommendation.
The summary for Mg shows that 82 percent of field
crop samples and 89 percent of horticultural samples were
H in Mg. This means that if these samples needed lime,
calcitic lime would be satisfactory. The other 18 and 11
percent respectively would need dolomitic limestone or
some other source of Mg for most crops.
SOIL pH DISTRIBUTION
Distribution among Soil Groups (Table 8)
Soils that are high in clay or organic matter require
more lime to raise the pH to 6.5 than do sandy soils that
are low in organic matter. Clay soils will produce top
yields at lower pH levels than will sandy soils. Lime is
recommended for most crops on Group 1, 2, and 4 soils
if the pH is below 5.8. On Group 3 and 5 soils, lime is
usually not recommended unless the pH is below 5.6.
Low pH is generally considered to be the most impor-
tant fertility problem in Alabama. This problem is most
prevalent in the Sand Mountain area where 67 percent of
samples were below pH 5.8. This was followed closely
by the sandy soils of the coastal plain where 58 percent
needed lime. Only 31 percent of the red clay soils of the
limestone valleys were below pH 5.5 and received a lime
recommendation. Almost 90 percent of the clay soils of
the Black Belt were high in pH and did not need lime.
The acid clay soils from the Black Belt were classified in
Ciroup 5 during the first few months of this year.
These. data demonstrate why it is important that a soil
test be made before lime is applied. Of all samples re-
ceived, 53 percent needed lime; and without a soil test,
the need for lime cannot be accurately predicted.
TABLE 6. SAMPLES RATED DY P, K AND Mg LEVELS FOR EACH SOIL 
GROUP
Phosphorus
VL L M H
--------2,003 3,041
Percent 7.9 12.0
4,082 3,403
Percent 17.8 14.8
____-_ -- 554 436
Percent 29.6 23.3
671 754
Percent 11.3 12.6
-------- 250 375
Percent 7.4 10.8
------7,566 8,009
Percent 12.7 13.5
7,200
28.5
4,774
20.8
386
20.6
1,412
23.7
719
20.7
14,491
24.4
8,173
32.4
4,395
19.2
264
14.1
1,599
26.8
992
28.6
15,423
25.9
VH RH VL
3,250
12.9
2,816
12.3
127
6.8
1,007
16.9
592
17.0
7,792
13.1
1,591
6.3
3,467
15.1
106
5.7
519
8.7
539
15.5
6,222
10.5
565
2.2
435
1.9
52
2.8
80
1.3
19
0.5
1,151
1.9
[6]
Potassium
L M
3.689 9,887
14.6 39.1
3,029 9,473
13.2 41.3
340 497
18.2 26.5
852 2,940
14.3 49.3
398 1,605
11.5 46.2
8,308 24.402 21
14.0 41.0
Magnesium
H VH L H
9,024
35.7
8,190
35.4
681
36.4
1,795
30.1
1,248
35.9
0,857
35.1
2,093
8.3
1,891
8.2
303
16.2
295
4.9
203
5.8
4,785
8.0
4,494
17.8
2,547
11.1
153
8.2
2,353
39.5
65
1.9
9,612
16.2
20,764
82.2
20,390
88.9
1,720
91.8
3,609
60.5
3,408
98.1
49,891
83.8
County
Autauga --
Bibb
Calhoun -_
Chilton----
Clay
Cleburne--
Fayette_--.
Greene ---
Jefferson.-_
Lamar ----
Piekens----
Randolph.-
Shelby-_--
St. Clair __-
Talladega.-
Tuscaloosa-
Walker_---
Soil
group
1
2 -- - -
3
4 - -
5
Total
Total Percent
25,258 42.4
100.0
22,937 38.5
100.0
1,873 3.1
100.0
5,962 10.0
100.0
3,473 5.8
100.0
59,503 100.0
100.0
TABLE 7. SAMPLES RATED BY P, K, AND Mg LEVELS FOR EACH CROP
Phosphorus
VL L M H VH EH VL
Potassium Magnesium T
L M H VH L H
C orn .-- -- --- --- -
C otton --- -- -- -- --
Peanuts .-- ---- ---
Soybeans----- 
--
Clover-Winter Crass
Clover-Summer Grass
Legumes .---- 
- --
Temp. WinterGrass_
Per. Winter Grass
Summer Grass
Coastal Bermuda
Fruits and Nuts
Truck Crops------
Tomatoes-Peppers -- _-
G ardens--------- 
---
L aw ns--------------
Shrubs -------------
T o ta l-- -- -- -- --- -
- --
Percent ------------
Total Field Crops----
Percent ------------
Total Hort. Crops____
Percent
525
122
199
733
1,339
197
116
58
893
1,662
346
637
50
8
595
535
121
7,566
12.7
6,190
13.7
1,376
9.7
1,319
376
670
1,073
729
129
113
56
579
1,431
386
49
44
16
600
358
81
8,009
13.5
6,861
15.2
1,148
8.1
3,115
1,211
1,936
1,779
712
191
110
103
678
2,186
681
763
75
30
1,013
477
118
14,491
24.4
12,702
28.1
1,789
12.6
3,218
1,930
1,933
1,687
580
149
100
98
559
2,076
742
104
134
44
1,324
591
154
15,423
25.9
13,072
28.9
2,351
16.5
956
1,222
438
639
273
62
43
42
290
873
330
140
110
48
1,448
658
220
7,792
13.1
5,168
11.4
2,624
18.5
141
174
25
179
155
26
16
20
172
280
175
92
25
2,847
1,118
677
6,222
10.5
1,288
2.8
4,934
34.7
30
17
106
96
184
33
20
5
26
185
97
14
17
2
165
120
34
1,151
1.9
582 3,531
294 2,586
873 2,362
1,176 3,002
1,035 1,570
159 286
122 239
35 120
343 1,100
1,097 3,080
506 992
84 209
91 229
23 81
1,038 2,931
655 1,574
195 510
8,308 24,402
14.0 41.0
4,130
2,028
1,644
1,607
833
237
111
165
1,214
3,114
799
231
151
55
2,893
1,197
448
20,857
35.1
1,001
110
216
209
166
39
6
52
488
1,032
191
72
17
10
800
191
184
4,785
8.0
7 99 6,222 18,868 15,882 3,510
1.8 13.7 41.7 35.1 7.8
352 2,086 5,534 4,975 1,275
2.5 14.7 38.9 35.0 9.0
2,481
572
994
1,008
497
48
90
58
484
1,299-
463
4,5
158
39
1,015
301
60
9,612
16.2
6,793
4,463
4,207
5,082
3,291
706
408
319
2,687
7,209
2,122
347
132
6,812
3,436
1,311
49,891
83.8
9,274
5,035
5,201
6,090
3,788
754
498
377
3,171
8,508
2,585
611
505
171
7,827
3,737
1,371
59,503
7,994 37,287 45,281
17.7 82.3 100.0
1,618 12,604 14,222
11.4 88.6 100.0
TABLE 8. SOIL PH DISTRIBUTION OF SAMPLES FROM THE FIVE SOIL GROUPS
Soil group Below 44 05 5755 04~AboVePecn
Code4.5-4.9 
5.0-5.4 5.5-5758 Name .5. 
5-6 .97.0-7.4 74 Total 
Percent
Code Name__________ 21 8 18 14 22 7 3 9
1 Sandy soils of
Coastal Plain _ Pr--- en
2 Loams and j v
Light clays----------
Percent
3 Clay soils of
Black Belt
Percent
4 Sandy loams of
North Ala.------ --- _
Percent
5 Red clay soils
Limestone Valley----.
Percent
Total
Percent
75 1,150 6,879 6,626 3,735 5,634 949 158 52 25,258
0.3 4.6 27.2 26.2 14.8 22.3 3.8 0.6 0.2 100.0
128 1,345 5,749 4,481 2,685 4,381 2,136 703 229 22,937
0.6 5.9 25.1 19.5 11.7 23.9 9.3 3.1 1.0 100.0
3
69
1.2
26 85 82 55 221 282 371 738 1,873
1.4 4.5 4.4 2.9 11.8 15.1 19.8 39.9 100.0
627 2,241 1,073 525 1,026 309 84 8 5,962
10.5 37.6 18.0 8.8 17.2 5.2 1.4 0.1 100.0
10 170
0.3 4.9
285 3,318
0.5 5.6
884
25.5
15,838
26.6
642
18.5
12,904
21.7
356
10.3
7,356
12.4
857 361 156 37 3,473
24.7 10.4 4.5 1.1 100.0
13,219 4,037 1,472 1,074 59,503
22.2 (.8 2.5 1.8 100.0
42.4
38.5
3.1
10.0
5.8
100.0
Distribution among Crops (Table 9)
Crops vary in the pH level required for optimum
growth. Alfalfa, most clovers, and tomatoes receive a lime
recommendation if the pH is below 6.0. Corn, cotton,
soybeans, peanuts, and most other crops should be grown
at pH 5.8 or above. A few crops such as bermudagrass,
bahia, and most lawn grasses grow well at pH 5.6 or
above. Lime is not recommended for potatoes, azaleas, or
tobacco unless the pH is below 5.0. Table 9 shows the
number of samples in 17 crop classifications by soil pH
classes.
Some important changes in numbers of samples sub-
mitted for the different crops occurred in the 2-year period
since 1973. The percentage of samples for corn increased
from 5 percent in 1973 to 16 percent in 1975. Approxi-
mately one-half of this shift had occurred in 1974, with
the other half occurring by 1975. Fourteen percent of the
1975 samples were for summer grass pasture including
babia, bermuda, dallis, and temporary summer grasses,
[7 ]
compared to 16 percent in 1973. The next most predom-
inant field crop was soybeans at 10 percent in 1975, eom-
pared to 7.5 percent in 1973. Samples from home gardens
were 18 percent of the total in 1975, and 8.0 percent in
1973.
The number of soybean samples received in 1975 is
more than double the number received in 1973. Soybeans
continue to increase in importance as a crop in Alabama.
In 1968, the number of samples for soybeans was so low
that it seemed that little consideration was being given to
direct fertilization of soybeans. During the 7 years since,
soybeans have moved to the second position in the ranking
of crops for which recommendations are requested.
Of the 1975 corn samples, 63 percent were below pH
5.8, most of which needed lime. Thirty-three percent of
the summer grass pasture samples were below pH 5.5 and
needed lime. For the soybean samples, 53 percent were
below 5.8. Fifty percent of the garden samples required
lime.
Crop
TABLE 9. SOIL PHI DISTRIBUTION OF SAMPLES FOR DIFFERENT CROPS
Crop
Corn-
C otton -- - - - - - - - - - -
Peanuts .-- - - - - - - -
Soybeans --
Cloyer-Winter Grass
Clover-Summer Grass
Legumes---- --- 
- --
Temp. Winter Grass
Perm. Winter Crass
Summer Crass ------------
Coastal Bermuda.---------
Fruits and Nuts-----------
Truck Crops--------------
Tomatoes-Peppers ---------
G ardens--------------- ---
L aw n s.- - - --- - - -- --- - - - --
S h ru b s.-- -- -- -- -- -- -- -- --
T o ta l - - - - - - - - - - - - - - - - - - -
-
P ercent ---- ---------- - ---
Acidity (pH)
Below 4.5-4.9 5.0-5.4 5.5-5.7 5.8-5.9 6.0-6.4 6.5-6.9 7.0-7.4 Above Total Percent
4.5
35 492 2,958 2,343 1,250 1,816 300 50 30 9,274 15.6
17 211 1,226 989 609 1,370 495 106 12 5,035 8.5
0 133 1,254 1,473 904 1,317 114 6 0 5,201 8.7
13 224 1,644 1,369 782 1,313 385 165 195 6,090 10.2
13 251 1,034 727 455 827 325 92 64 3,788 6.4
0 24 129 145 79 209 71 24 73 754 1.3
1 39 163 91 49 106 27 7 15 498 0.8
1 19 116 72 44 81 19 8 17 377 0.6
7 183 878 579 370 692 243 117 102 3,171 5.3
44 507 2,295 2,036 1,074 1,777 435 143 197 8,508 14.3
23 226 806 595 306 499 109 16 5 2,585 4.3
5 19 132 137 79 171 33 23 12 611 1.0
6 53 183 113 52 63 26 4 5 505 0.8
0 13 42 38 23 40 10 4 1 171 0.3
64 584 1,890 1,387 754 1,692 833 424 199 7,827 13.2
41 264 848 641 404 892 395 164 88 3,737 6.3
15 76 240 169 122 354 217 119 59 1,371 2.3
285 3,318 15,838 12,904 7,356 13,219 4,037 1,472 1,074 59,503 100.0
0.5 5.6 26.6 21.7 12.4 22.2 6.8 2.5 1.8 100.0
FERTILIZER GRADES RECOMMENDED FOR been primarily in the 1 to 1 ratio.
THE DIFFERENT SOIL GROUPS The ratios recommended for the different 
soil groups
I t t b r hcan be determined from the data in Table 10. The per-
In17,tefoltsin 
aoaoy rdcdtenme 
centages needing 
the different ratios and 
those sold in
of P
2
0
5 
to K
2
0 fertilizer ratios recommended to 1-l, 2-1, Alabama from October 1974 through August 1975 are
and 1-2. Since P or K are no longer recommended at High shown in Table 11. Only 27 percent of samples needing,
levels, many samples get recommendations. of P alone or P or K needed a 1-1 ratio while 83 percent of the PK
K alone with the amount of N needed for the crop to be fertilizer sold were grades of this ratio. There 
is a need
grown. The grades sold in Alabama in recent years have for more 
2-1 grades and less of the 1-2 or 2-3 grades thin
TABLE 10. PK RATING COMBINATIONS BY SOIL GROUPS
Soil group
1 2 3
215 240
696 1,195
792 1.899
261 663
39 85
118 88
678 678
1,375 1,637
780 848
90 152
135 47
1,104 531
3,040 2,316
2,521 1,669
400 211
73 38
845 320
3,136 1,823
3,311 1,859
808 355
19 15
266 162
1,037 950
1,485 1,384
443 305
5 7
100 143
507 848
666 1,686
313 783
_25,258 22,937
42.45 38.55
34
148
178
151
43
5
80
134
177
40
2
51
91
170
72
9
33
48
106
68
2
23
26
42
34
0
5
20
35
46
4 5
40
296
281
51
3
19
191
424
113
7
15
198
854
327
18
4
109
826
598
62
1
46
420
465
75
1
12
135
241
130
9
107
114
25
1
2
119
197
52
5
3
1 04
435
165
12
4
55
533
368
32
1
7
208
336
40
0
6
118
302
113
Total Percent
538 0.90
2,442 4.10
3,264 5.49
1,151 1.93
171 0.29
232 0.39
1,746 2.93
3,767 6.33
1,970 3.31
294 0.49
202 0.34
1,988 3.34
6,736 11.32
4,852 8.15
713 1.20
128 0.22
1,362 2.29
6,366 10.70
6,242 10.49
1,325 2.23
38 0.06
504 0.85
2,641 4.44
3,712 6.24
897 1.51
13 0.02
266 0.45
1,628 2.74
2,930 4.92
1,385 2.33
1,873 5,962 3,473 59,503 100.00
3.15 10.02 5.84 100.00
Rating P Totals K Totals
VL- 7,566 1,151
(%f 12.7 1.9
L- 8,009 8,308
io 13.5 14.0
M- 14,491 24,402.
X0 24.4 41.0
HI- 15,423 20,857
(% 25.9 35.1
VII- 7,792 4,785
% 13.1 8.0
EH- 6,222
r 10.5
[8]
P-K Ratings
VL- VL---
L---
L
M --
M- VL__
L _-
M--
H---
H- VL--
L.--
M --
H--
VH__
VHI- VL--
L --
M --
H --
VH---
EH- VL--
L --
M-
H-
VHII-
Total --
Percent-
1 u ie b rcbe~~~e~r eb ~ ,
-- - - - - - -- - -- - -
TABLE 11. PERCEN'T'AGE OF SAMPLES NEEDING VARIOUS P
2
0
5 
TO K
2
0 RATIOS FOR THE FIVE
SOIL GROUPS, AND RATIOS SOLD IN ALABAMA, OCT. 1974 THROUGH AUGUST 1975
PgOf those Fertilizer
P-K ratings ratio 
KSneeded 1 
3 4 
5T - needing 
sales
rati neeed 12 3 5 Ttal fertilizer
L-L, M-M--------------- 1-1 19 20 19 23 19 20 27 83
L-M --------------- 2-1 8 15 17 12 9 12 16 1
M -L ------------------------ 1-2 5 3 3 4 3 4 5 13*
L-H, M-H----------- 1-0 16 16 35 9 7 15 21 1
H-L, H-M------------- 0-1 24 19 9 26 27 22 30 2
H-H _ ---------------- 0-0 28 28 18 26 34 28
*Includes 2-3 ratio.
TABLE 12. SAMPLES RATED BY P AND K FOR EACH CROP
Small Fruits Lawns
P- Crn Coto PantsSobensClover-Lers grain Coastal truck shrubs Toa Pecn
P-K orn otto PenutsSoybansgrassLms winter bermuda crops flowers Toa Pecn
grass gardens grnhouse
VL- VL ----- --- 5
L -------- 111
M --------- 298
H-------------- 104
V H ---------- 7
L- VL-------- 10
L -------- - 133
M -------- -- 665
H ---------- 456
VH ------ - 55
M - VL---- ----- 11
L -------- - 193
M ---------- 1,288
H ---------- 1,394
VH---------- 229
H- VL---------- 4
L ---------- 120
M --------- 1,034
H ---------- 1,590
VH---------- 470
VH- VL---------- 0
L --------- 21
M------------ 219
H ---------- 524
VH------------- 192
EH- VL---------- 0
L ----- --- -- 4
M --- ------- 27
H ----------- 62
VH ---------- 48
Total------------- 9,274
Percent ----------- 15.6
7
46
60
8
1
2
58
249
67
0
4
98
759
341
9
3
71
1,004
815
37
1
18
472
690
41
0
3
42
107
22
5,035
8.5
16
85
74
22
2
26
192
312
132
8
39
353
946
548
50
21
213
870
737
92
4
26
151
197
60
0
4
9
8
4
5,201
8.7
53
291
308
68
13
22
343
499
196
13
14
319
993
419
34
6
184
872
561
64
1
34
275
286
43
0
5
55
77
42
6,090
10.2
217
1,003
1,343
548
87
82
468
1,002
612
125
58
440
1,232
1,137
222
30
278
947
1,163
387
11
81
321
551
244
4
21
91
173
172
13,050
21.9
5
42
55
14
0
8
32
53
19
1
4
28
52
26
0
3
16
52
26
3
0
3
18
21
1
0
1
9
5
1
498
0.8
18
192
461
238
42
5
83
254
235
58
3
54
268
348
108
3
38
165
326
125
1
10
60
165
96
1
1
12
67
111
3,548
6.0
24
93
161
60
8
30
97
159
81
19
24
148
272
209
28
13
120
280
262
67
5
41
99
151
34
1
7
21
36
35
2,585
4.3
94
320
252
49
5
30
224
347
100
8
32
235
627
278
22
32
205
786
530
53
8
146
661
801
130
2
106
777
1,572
682
9,114
15.3
99
259
252
40
6
17
116
227
72
7
13
120
299
152
11
13
117
356
232
27
7
124
365
326
56
5
114
585
823
268
5,108
8.6
538
2,442
3,264
1,151
171
232
1,746
3,767
1,907
294
202
1,988
6,736
4,852
713
128
1,362
6,366
6,242
1,325
38
504
2,641
3,712
897
13
266
1,628
2,930
1,385
59,503
100.0
0.9
4.1
5.5
1.9
0.3
0.4
2.9
6.3
3.3
0.5
0.3
3.3
11.3
8.2
1.2
0.2
2.3
10.7
10.5
2.2
0.1
0.8
4.4
6.2
1.5
0.0
0.4
2.7
4.9
2.3
are being sold. The greatest need for change in fertilizers
sold is in the P alone or K alone materials throughout the
State.
The soil areas are quite uniform in the ratios needed.
The clayey soils of the Black Belt in Group 3 need more
P and less K than the other areas. The soils of Sand
Mountain and the Tennessee Valley need less straight P
than the other areas but much more than is being sold.
Of all samples received, 28 percent were High in both P
and K and would not be expected to respond to either of
these elements.
FERTILIZER GRADES RECOMMENDED
FOR THE DIFFERENT CROPS
The numbers of samples in the PK rating combinations
for the various crops are presented in Table 12. Over
40 percent of all samples were in the M-M, M-H, H-M,
and H-H categories. These data have been summarized
in Table 13 to indicate the grades of fertilizer needed
[9]
for different crops. Of all field and forage crop samples
needing P or K, 28 percent needed 1-1 fertilizers, 17 per-
cent needed 2-1, and only 5 percent needed low P-high K
grades. About one-half of these samples needed only P
or only K with the number being equally divided between
the two elements. About one-third of all samples for cotton
and for corn contained, adequate P and K for maximum
production. Peanuts showed a need for more 1-2 grades
than the other crops, while the forage crop samples needed
more 2-1 fertilizers than did the row crops.
Since maintenance applications of low rates of P and K
are still recommended for most horticultural crops at High
soil test levels, 53 percent of these samples that needed
either P or K needed 1-1 grades. The buildup of P in
most of these samples led to the remainder needing Low
P-High K grades or materials containing only K.
These data indicate that there is a great need for changes
in the grades of fertilizer offered to growers in Alabama.
The percentage of fertilizer mixed in the 1-1 ratio should
be drastically reduced. Straight P or K materials should
-- -- r\llrr CA
TABLE 13. PERCENTAGE OF SAMPLES 
NEEDING VARIOUS P20O TO K
2
0 RATIOS FOR THE DIFFERENT CROPS
Field crops Horticultural 
crops
P-K ratings P
2
0
5 
to K
2
0 Corn Cotton Peanuts Soybeans Forage 45,281 
34,290 9,484
samples 
needing 
aeedg
s P o K samples P or K
L-L, M-M _ 1-1 17 
17 24 28 21 21 
28 35* 53
L-M- .. 2-1 
10 6 7 13 
18 13 17 
0 0
M-L---------------- 1-2 
2 2 8 5 4 
4 5 11 16
L-H, M-H- 1-0 
24 8 15 12 22 
19 25 1 
1
H-L, H-M -- - 0-1 
15 32 25 24 
14 19 25 20 
30
H-H ---------- ------ 0-0 
31 34 21 18 21 
24 33*
* Most horticultural samples 
rating High received a maintenance 
recommendation while 
only those rating Very High 
or Ex-
tremely High did not get a P or K recommendation.
be made available to growers and the percentage 
of 1-2
grades sold should be reduced in favor of the 2-1 grades
that are being sold in very limited quantities. 
These
changes would allow farmers to meet the fertility 
needs
of their crops at much lower costs and would reduce 
the
waste of P or K where it is being applied 
to crops on soils
that will not respond to it. If farmers could 
buy the grades
that soil tests show they need, 
they should be encouraged
to use soil tests to determine what 
grades and amounts
they should apply to maximize profits.
CALCIUM RATINGS OF SAMPLES 
FOR PEANUTS
FROM 13 COUNTIES (TABLE 
14)
Calcium levels of samples for peanuts 
for 1975 are
given in Table 14. There is little 
difference between 1974
and 1975, but there is a significant 
shift from the distribu-
tion in 1972, the last year for which 
data is available. The
samples rated low were 14 percent in 
1974 and 13 percent
in 1975, compared to 26 percent 
in 1972. Those rated
medium were 27 percent in 1974, 26 
percent in 1975, and
42 percent in 1972. The samples 
rated high in 1974 were
58 percent of the total, and those 
rated high in 1975 were
62 percent, compared to 32 percent 
in 1972. Beginning
in 1973, the soil-test Ca levels 
at which soil were rated
Medium were lowered from 
250 pounds Ca per acre to
175 and ratings for High were 
lowered from 400 to 300.
This had the effect of moving 
some of the samples to the
higher ratings. Less gypsum is now 
recommended on soils
of adequate pH. Lime recommendations 
are the same as
previous pH levels, but the increase 
in plow depth for
which lime is recommended 
from 6 inches to 8 inches has
had the effect of increasing 
the amounts recommended 
by
one-third.
On the 12.5 percent of the 
samples rated Low in Ca in
1975, gypsum was recommended, 
even where lime was
also recommended. Gypsum 
was recommended on the
25.9 percent of the 1975 
samples rated Medium in 
Ca
only where the pH was above 5.7 
and no lime was needed.
These figures compare with 
26 percent and 42 percent 
in
1972.
TABLE 14. CALCIUM-NUMBER AND PERCENT OF 
PEANUT SAMPLES RATING
Low, MEDIUM AND HIGH FOR 13 
COUNTIES-1975
Calcium rating
County Low Medium High 
Total
Number Percent Number Percent Number Percent 
Number Percent
Barbour 102 
27.3 133 35.6 
139 37.2 374 
7.2
Bullock 10 
25.6 16 41.0 
13 33.3 39 
0.8
Butler 4 
16.7 7 29.2 
13 54.2 24 
0.5
Coffee - 92 
12.5 171 23.2 
475 64.4 738 
14.3
Conecuh......... 4 
13.8 4 13.8 
21 72.4 29 
0.6
Covington ------- 36 
13.4 69 25.7 
163 60.8 268 
5.2
Crenshaw 26 
9.9 94 35.9 
142 54.2 262 
5.1
Dale - - 65 
16.4 125 31.5 
207 52.1 397 
7.7
Geneva 55 
10.1 133 24.5 
355 65.4 543 
10.5
Henry 103 
10.9 225 23.8 
618 65.3 946 
18.3
Houston--------- 88 
8.3 232 21.8 
743 69.9 1,063 
20.6
Pike------------ 58 
12.9 117 25.9 
276 61.2 451 
8.7
Russell---------- 2 
8.0 8 32.0 
15 60.0 25 
0.5
Total 1975.------ 645 
12.5 1,334 25.9 
3,180 61.6 5,159 
100.0
Total 1974 483 
14.2 935 27.4 
1,989 58.4 3,407 
100.0
[10]

4