Submitted to: Bay Area Scientific Information Symposium
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2004
Publication Date: 5/1/2005
Citation: Sigua, G.C., Holtkamp, M.L., Linton, J.M., Coleman, S.W. 2005. Lake-dredged materials for beef cattle pasture establishment in subtropics. Proceedings 4th Tampa Bay Area Scientific Information Symposium. p. 239-244. Interpretive Summary: Bahiagrass, a warm season perennial, is largely grown throughout Florida, the Coastal Plain, and the Gulf Coast regions of the southern United States. The pastures are used mainly for beef cattle pastures. Bahiagrass is a good general-use pasture grass that can tolerate a wide range of soil conditions and close grazing, and withstands low fertilizer input. It has the ability to produce moderate yields on soils of very low fertility and is easier to manage than other improved pasture grasses. Establishment of an excellent, uniform stand of BG in a short time period is essential and economical. Failure to obtain an early good stand means the loss of not only the initial investment costs, but production and its cash value. Forage production often requires significant inputs of lime, nitrogen fertilizer, and less frequently of phosphorus and potassium (K) fertilizers. Dredged materials, composted urban plant debris, waste lime, and phosphogypsum are examples of materials that can be used for fertilizing and liming pastures. Often these materials can be obtained at little or no cost to the farmers or landowners. The bottom sediments that were dredged from Lake Panasoffkee did not contain any materials that would be classified as hazardous or as a human health risk. Therefore, dredging, handling, and disposal were relatively inexpensive.
Technical Abstract: The ability to reuse dredge materials for agricultural purposes is important because it reduces offshore disposal and provides an alternative to disposal of the materials in landfills that are already overtaxed. Beneficial uses of dredging or dredged materials are both economical and environmental. Economically, dredged materials can be used as soil amendments (lime and fertilizer) for early establishment of forage in beef cattle pastures. Often these materials can be obtained at little or no cost to the farmers or landowners. Productive disposal options of lake-dredged materials (DM) may provide substantial and intangible benefits that will enhance the environment, community, and society. The objective of this study was to assess lake-dredged materials from Lake Panasoffkee (LP) as soil amendment for early establishment of bahiagrass (BG, Paspalum notatum Flügge) in subtropical beef cattle pasture. The treatment combinations consisted of five test plots (30.5 x 30.5 m). Each of the plots had different ratio of DM to natural soil (NS): Plot 1 (0% DM:100% NS); Plot 2 (25% DM:75% NS); Plot 3 (50% DM: 50% NS); Plot 4 (75% DM:25% NS); and Plot 5 (100% DM:0% NS). Each plot was seeded with BG and yield establishment were monitored at 16, 34, and 78 weeks. Results disclosed consistently and significantly higher BG biomass production (P ' 0.001) from plots amended with DM than those of BG planted on plots with 0% DM at 16, 34, and 78 weeks, respectively. Addition of DM had significant effects on soil properties. Compared with the control plots, the soils in plots amended with DM exhibited: (1) an increase in soil pH, Ca, and Mg; (2) a decrease in the levels of soil Mn, Cu, Fe, Zn, and Si; and (3) no significant change in the level of Na in the soil.