THE EFFECTS OF DRYING UPON EXTRACTABLE PHOSPHORUS, POTASSIUM AND BULK-DENSITY OF ORGANIC AND MINERAL SOILS OF THE EVERGLADES

The effect of drying 10 organic and mineral soils originating from the Florida Everglades Agricultural Area upon extractable levels of phosphorus and potassium was studied. When measurements of phosphorus and potassium were expressed volumetrically (w/v), variability in soil test levels of phosphorus and potassium were largely a result of changes in water content and dry bulk density. This variability was reduced when the results were expressed gravimetrically (w/w) or when the drying procedures were standardized. The variability of soil test levels of phosphorus and potassium expressed volumetrically was present in mineral and organic soils but was more pronounced on organic soils which were susceptible to large changes in dry bulk density upon extensive drying. Refs.