DOI: http://dx.doi.org/10.1065/jss2003.04.075
BACKGROUND. The continued need to dredge lakes, rivers, and canals in Florida, both for maintenance and environmental improvement, will produce millions of cubic meters of dredged materials. Productive disposal options of lake-dredged materials (LDM) may provide substantial and intangible benefits that will enhance the environment, community, and society.
OBJECTIVE. The objective of this study was to assess lake-dredged materials from Lake Panasoffkee as soil amendment for early establishment of bahiagrass (BG, Paspalum notatum Flügge) in subtropical beef cattle pasture at Sumter County, Florida.
RESULTS AND DISCUSSION. This study encompassed two phases: Phase 1 comprised of five small observation plots (0.3 x 0.3 m); Phase 2 consisted of five larger test plots (30.5 x 30.5 m). Each of the plots in Phase 1 and Phase 2 had a different ratio LDM to natural soil (NS): Plot 1 (0% LDM + 100% NS); Plot 2 (25% LDM + 75% NS); Plot 3 (50% LDM + 50% NS); Plot 4 (75% LDM + 25% NS); and Plot 5 (100% LDM + 0% NS). Each plot was seeded with BG and early growth and yield establishment were monitored for 16 weeks.
CONCLUSION. Results disclosed significantly taller (p ≤ 0.001) plants and higher biomass production (p ≤ 0.001) of BG from plots amended with 75% LDM than those of BG planted on plots with 0% LDM. Results suggest that LDM can serve as source of lime and fertilizer to establish BG beef pasture fields. Sediments with high CaCO3 improved the physical and chemical conditions of subtropical beef pastures. Lake-dredged materials could be removed from the spoil containment areas, trucked to other locations, and incorporated into existing fields for agricultural uses. There is still much to be learned, but it is certain that Lake Panasoffkee sediments should be regarded as a resource, with no observed harmful ecological effects.
RECOMMENDATION AND OUTLOOK. The agricultural or livestock industry could utilize these LDM to produce forages. LDM should be regarded as a beneficial resource, as a part of the ecological system. This study has been continued for several years to explore and assess the long term efficacy of LDM on productivity and quality of BG beyond its early establishment stage.
ABBREVIATIONS: Analysis of variance (ANOVA); bahiagrass (BG, Paspalum notatum Flügge); Coleman Landing (CL); Duncan Multiple Range Test (DMRT); lake-dredged materials (LDM); least significant differences (LSD); natural soil (NS); probable effect levels (PEL); St. Johns River Water Management District (SJRWMD); Southwest Florida Water Management District (SWFWMD); threshold effect levels (TEL) |
