Submitted to: Tropical Agriculture (Trinidad)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/10/2005
Publication Date: 7/15/2005
Citation: Sigua, G.C., Coleman, S.W. 2005. Establishing bahiagrass in subtropical beef cattle pastures with lake-dredged materials. Tropical Agriculture (Trinidad). 82(4):354-359.
Interpretive Summary: Disposal or finding beneficial uses of dredged materials is quite challenging. The bottom sediment materials usually are composed of upland soil enriched with nutritive organics. These materials should be regarded as a beneficial resource to be used productively and not to be discarded as spoil materials. The objective of this study was to assess dredged materials (DM) as a soil amendment to establish bahiagrass (BG) in a subtropical beef cattle pasture in Sumter County, Florida. The ability to reuse dredge materials from Lake Panasoffkee 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. The bottom sediments that were dredged from Lake Panasoffkee contained neither materials that would not classify them as a human health risk nor would require expensive hazardous waste handling and disposal. The heavy and trace metal contents of these materials were below the probable effect levels and threshold effect levels. As such, the agricultural or livestock industry could utilize these DM to produce forages. DM should be regarded as a beneficial resource, as a part of the ecological system. This study is expected to continue for several years to explore and assess the long term efficacy of DM on productivity and quality of BG beyond its early establishment stage.
Technical Abstract: Dredged materials (DM) are often viewed by society and regulators as pollutants, but many have used these materials in coastal nourishment, land or wetland creation, construction materials, and for soil improvement as a soil amendment. The objective of this study was to assess lake-dredged materials as soil amendment for early establishment of bahiagrass (BG, Paspalum notatum Flügge) in subtropical beef cattle pasture. The treatment combinations were consisted of five test plots (30.5 x 30.5 m). Each of the plots had different ratio of lake-dredged materials (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 growth and yield establishment were monitored for 34 weeks. Results disclosed significantly taller (p = 0.001) BG and higher biomass production (p = 0.001) from plots amended with DM than those of BG planted on plots with 0% DM. Results suggest that DM can serve as source of lime and fertilizer to establish BG beef pasture fields in subtropics.