Everglades agricultural area soil subsidence and land use projections

The organic soils (Histosols) of the Everglades Agricultural Area (EAA) formed when organic matter (OM) production exceeded OM decomposition because of flooded conditions that limited soil oxygen. Following drainage of the EAA, OM decomposition has exceeded production, resulting in loss of soil and a lowering of the surface elevations (subsidence). Predictions made in 1951 of the demise of agriculture in the EAA by 2000 did not materialize because growers found ways of adapting to decreasing soil depths, and sugarcane (Saccharum spp.), which is fairly water tolerant, became the principle crop. What about the next 50 yr? It is projected that in 2050 nearly half of the EAA will have soils < 8 inches (20 cm) in depth, primarily south of the Bolles canal. Sugarcane production will be difficult and costly on the more shallow soils, but not impossible. These areas should be suitable for pasture, but not for most vegetables. Water control will be crucial, since soil storage will be minimal. More of the EAA could be suitable for agriculture with implementation of soil-conserving practices. Future agricultural production in the EAA may depend more on commodity prices and governmental policies than on soil depths. Urban planners predict minimal population increases in the EAA, but relatively low land prices may be attractive to developers. Particularly on severely subsided soils, landowners may explore biomass production, aquaculture, hunting reserves, water storage, and mining as alternatives to traditional agriculture.