Land Application of Carbonatic Lake-Dredged Materials: Effects on Soil Quality and Forage Productivity.
Authors:
Sigua, G.C. Coleman, S.W. Holtkamp, M.L. USDA, ARS
Source:
Journal of environmental quality. 2006 Sept-Oct, v. 35, no. 5, p. 1784-1794.
NALT Subjects:
lakes dredged materials land application landfills sandy soils soil amendments beef cattle pastures subtropics Paspalum notatum forage production nutritive value dry matter accumulation phosphorus nitrogen content soil penetration resistance soil chemical properties protein content chemical constituents of plants Florida
Issue Date:
Sep-2006
Abstract:
The ability to reuse carbonatic lake-dredged materials (CLDM) 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. A four-year (2001 to 2005) study on land application of CLDM as an option for disposal was conducted on a beef cattle pasture in south central Florida. The objectives of this study were (i) to assess CLDM as a soil amendment to improve quality of sandy soils in most subtropical beef cattle pastures and (ii) to determine the effect of CLDM on productivity and nutritive values of bahiagrass (BG, Paspalum notatum Flugge) in subtropical beef cattle pasture. The five treatment combinations arranged in randomized complete block design were represented by plots with different ratios (R) of natural soil (NS) to CLDM: R1 (1000 g kg-1:0 g kg-1); R2 (750 g kg-1:250 g kg-1); R3 (500 g kg-1:500 g kg-1); R4 (250 g kg-1:750 g kg-1); and R5 (0 g kg-1:1000 g kg-1). Addition of CLDM had significant (p < or = 0.001) effects on soil quality and favorable influence on forage establishment and nutritive values. Compared with the control plots (0 g kg-1), the soils in plots amended with CLDM exhibited (i) lower penetration resistance, (ii) an increase in soil pH and exchangeable cations (Ca and Mg), and (iii) decrease in the levels of soil trace metals (Mn, Cu, Fe, Zn, and Si). Results disclosed consistently and significantly (p < or = 0.001) higher BG biomass production (forage yield = -106.3x2 + 1015.8x - 39.2; R2 = 0.99**) and crude protein content (CP = 1.24x + 6.48; R2 = 0.94**) from plots amended with CLDM than those of BG planted on plots with no CLDM treatment.
