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B. Effects of pH on some soil test results:


 The following soil test results made under routine Everglades Experiment
Station soil test procedures are taken from plots where pH levels were lowered
with agricultural sulfur. Soil phosphorus was determined from distilled water
extraction and calcium and magnesium from 0.5 N acetic acid extraction. Samples
from all plots were taken at harvest following uniform fertilization of each
plot. For the sake of brevity, potassium determinations are omitted as pH
effects on potassium levels in both soil and plant tissue were not found to be
significant.

Table 2. Soil test results as influenced by adjusted pH.


phosphorus
 lbs./A.
 18.
---8---

 25
 34
 39+

phosphorus
Ibs./A.
 19
 21
 24
 28

phosphorus
lbs./A.
 17
 29
 40+


calcium
lbs./A.
2944
2569
2413
2124

calcium
lbs./A.
3919
3488
3194
3019


magnesium
 Ibs./A.
 1219
 1125
 1129
 1041

 magnesium
S lbs./A.
 1271
 1166
 1147
 1096


Calcium and Magnesium were not
determined.


 Plots 5 and 7 were located on sawgrass peat. Plot 6 on Okeelanta peaty muck.

 The increasing solubility of phosphorus as pH levels were lowered shows
 what happens to soil phosphorus levels when the pH levels on highly fertilized
 high pH soils are lowered.

C. Some crop responses to pH adjustment:

 1. Early Experiments

 When celery yield and quality data were originally correlated with Ever-
 glades Experiment Station soil tests, a golden type celery was being grown
 and used to obtain the necessary data. It showed a large response to pH levels,
 which may have been in large measure due to manganese availability as the
 seedbed experiment cited definitely indicates.


Plot 5:
 pH
 6.24
 5.84
 5.21
 4.85

Plot 6:
 pH
 6.50
 5.94
 5.75
 5.53

Plot 7:
pH

5.53
5.20