Submitted to: Florida Cattleman
Publication Type: Trade Journal
Publication Acceptance Date: 10/20/2006
Publication Date: 11/1/2006
Citation: Sigua, G.C., Coleman, S.W. 2006. Wetland conversion to beef cattle pasture: Effect on soil phosphorus. The Florida Cattleman and Livestock Journal. 71(2): 56-60.
Technical Abstract: To better understand the chemical response of soils during wetland conversion to beef cattle pasture, soil samples were collected from the beef cattle pastures and from the adjoining natural wetland. This study was conducted on a 101-acre site within a 400-acre historic wetland that was largely drained and converted to a beef cattle pasture in the early 1940’s. Cattle production at the study site is forage-based with bahiagrass (Paspalum notatum, Flugge). Soil core (0-8; 8-16; 16-32; and 32-64 inches) samples were collected from 11 locations in the beef cattle pasture and four locations in the adjoining natural wetland in the summer of 2002 and 2003 with a hydraulic sinker drill. Our results did not support our hypothesis that wetland conversion to beef cattle pasture may increase the levels of soil nutrients, especially P. The concentrations of soil total phosphorus and all fractions of P were significantly lower in pastures than in the reference wetland. Levels of total phosphorus, water soluble P, FeMn-bound P, Organic-bound P, and CaMg-bound P differed with land use by soil depth while levels of NH4-bound P and Al-bound P were not affected by the interactions of land use and soil depth. Wetland soils had higher concentrations (totaled across soil depth) of Al-bound P (1744), apatite P (169), redox-sensitive P (171), and organic-bound P (649) than did pasture soils (699, 42, 41, and 328 ppm, respectively). The mean concentration difference between wetlands and pastures may reflect a decline in total phosphorus concentration as a result of wetland conversion to pasture.