The chemical and physical properties of organic soils of the Everglades Agricultural Area (EAA) are changing as a result of land management practices, drainage, and subsidence. Main effects of agriculture include increasing soil pH and incorporation of CaCO3 into surface soils by tillage, which influence P retention and transformations. The objectives of the study were to determine effects of projected increases in soil Ca levels on P fertilizer distribution using comparisons between farmed and unfarmed sites. Agricultural utilization of organic soils in the EAA results in increases in soil Ca levels due to soil loss by subsidence and increasing proximity to CaCO3 bedrock. Soil P storage was greater in farmed than unfarmed soils due to fertilization. Phosphorus retention was greater in farmed soils due to higher Ca levels, which increased the proportion of applied P in the HCl-P fraction. Approximately 40% of applied P was observed in the Ca-bound pool for farmed soils compared to 15% for unfarmed soils. The majority of P storage for unfarmed soils was in the humic-fulvic acid fraction (40%). 25% more P persisted in plant-available forms for unfarmed than farmed soils after incubation. The rate of decrease in plant-available P after fertilizer application was significantly greater for farmed than unfarmed soils. Increased P retention into unavailable plant forms in farmed soils indicates that higher P fertilization rates will be necessary in the future as soil subsidence continues.