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Table 1. Minimum phosphorus and potassium soil test values required for
 satisfactory production of some crops grown on organic soils in
 the Everglades.

 Crop P K
 Lbs/A Lbs/A

 Celery 30 300
 Potatoes 12-15 150
 Sweet Corn 8-10 150
 Lettuce 8-10 120
 B. E. Peas 8 120
 Cabbage 8-10 86-100
 Snap Beans 6-7 75-100
 Pasture 4-6 75-80


 A summary of results of 200 samples of virgin soil and 4000 samples of
crop soils (not including pastures) analyzed in the soil testing laboratory
during the past five years indicates that approximately two-thirds of the virgin
soils contain too little phosphorus for satisfactory production of most vegetable
crops. As can be seen in Table 2, the average phosphorus content tends to in-
crease somewhat on cultivated land.

Table 2. Levels of water-extractable phosphorus in the organic soils of
 the Everglades*.


 Water-extractable P Percent of total samples
 Lbs/A Virgin Cropped

 0.4 18.8 18.6
 5-6 16.4 11.4
 7-10 31.3 18.3
 11-20 25.0 30.1
 21-30 6.5 13.1
 S30 2.0 8.5

 Summary of analyses of 200 samples from virgin, and 4000 samples
 from cropped, organic soils analyzed by soil testing laboratory,
 Everglades Experiment Station, 1953-57.


 On the basis of the summary mentioned above, more than 80 percent of the
virgin soils contain insufficient potassium for satisfactory production of any
commonly grown field or vegetable crop (Table 3). On land that has been cropped
for a number of years, however, only 40 percent of the soils are deficient in
potassium for such crops as pasture, beans, and cabbage.