Submitted to: International Journal of Food, Agriculture, and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2005
Publication Date: 11/21/2005
Citation: Morris, D.R., Gilbert, R.A. 2005. Inventory, crop use, and soil subsidence of histosols in Florida. International Journal of Food, Agriculture, and the Environment. 2005. 3(3-4):190-193.
Interpretive Summary: Histosols in Florida are an important natural resource for crop production. However, they subside when drained due to microbial decomposition of organic matter. They also release high amounts of N and P that can be utilized by crops under drained conditions, which make them desirable for agricultural use. The disadvantage is that P can enter the waterways. A survey of all counties in Florida was conducted to determine the inventory and crop use of Histosols in Florida and assess the crop uses of Histosols for reduced soil subsidence. Our survey indicated there are 1.6 million ha of Histosols in Florida, and 85% of the counties of Florida have more than 4,000 ha of Histosols. The largest areas of Histosols are in the Everlgades, Upper St. Johns's River/Fellsmere, and Polk county areas. Of the total Histosols, only 12% are used for crop production. Sugarcane is grown on the largest percentage of the area followed by pasture, and timber. Those three crops represent 92% of the total cropped hectarage on Histosols. The best use of the Histosols for reduced soil subsidence would be under flooded conditions, but economic flood tolerant crops have not been identified. Of the economically valuable crops, the three major crops grown on Histosols are the best crops to grow, because they would be expected to result in the lowest subsidence rates compared to vegetable or sod crops: sugarcane results in lower rates of organic matter decomposition compared to other crops and pasture and timber can be produced without tilling the soil.
Technical Abstract: Histosols are a fragile natural resource, and subside when drained due to organic matter oxidation by aerobic microorganisms. The purpose of this study was to report on the inventory and crop use of Histosols in Florida and assess the crop uses of Histosols for reduced soil subsidence. An inventory of Histosols in Florida was conducted by counting the hectares of Histisols in NRCS (Natural Resources Conservation Service) soil surveys and estimating number of hectares of Histosols from old soil surveys in areas of Florida that were not mapped by NRCS. Crop inventory surveys were sent to NRCS or county extension agents in all counties of Florida to obtain an estimate of cropped hectares. There are 1.6 million ha of Histosols in Florida. Eighty-five percent of all counties in Florida have more than 4,000 ha of Histosols. The largest areas of Histosols are located in the Everglades, upper St. Johns River/Fellsmere region, and Polk county. About 12% of the Histosols in Florida are cropped with sugarcane (Saccharum spp.), pasture, and timber representing 92% of the cropped hectarage. Growing crops under flooded conditions would be the best use of the Histosols for reduced soil subsidence, but profitability of flooded crops such as rice is low. Since past research has shown sugarcane fields have lower soil subsidence rates than pasture (various species) and vegetable crops (various species), and since pasture and timber (various species) are not tilled, which reduces soil organic mattter oxidation rates compared to tilled crops, it appears that the best agricultural use of most Histosols for economic benefits and low soil subsidence is currently being practiced in Florida.