Submitted to: Florida Scientist
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2006
Publication Date: 8/1/2006
Citation: Sigua, G.C., Kang, W., Coleman, S.W., Albano, J.P. 2006. From wetland to beef cattle pasture: impact on soil nutrient dynamics. Florida Scientist.69(1):26-28.
Technical Abstract: Largely influenced by the passage of the Swamp Land Act of 1849, many wetlands have been lost in the coastal plain region of southeastern United States primarily as a result of drainage to convert land for agriculture. This study examined changes in soil carbon, pH, and Mehlich extractable nutrients in soils following conversion of wetland to beef cattle pasture. To better understand the chemical response of soils during wetland conversion to beef cattle pasture, soil samples were collected from the converted beef cattle pastures and from the adjoining reference wetland. Eleven sites were sampled from the beef cattle pasture, and four sampling sites were established and sampled from the adjoining reference wetland. Data that were collected from the reference wetland sites were used as the reference/baseline data to detect potential changes in soil properties associated with the conversion of wetlands to beef cattle pastures from 1940 to 2002. Overall, conversion of wetland had significant effects on soil carbon, pH, nitrogen, phosphorus speciation, and extractable nutrients. Results of our study have shown a decrease in TOC, TN, WSP, and K and an increase in soil pH, Ca, Mg, Mn, and Fe. In 2002, the amount of TOC and the concentration of soil organic matter in pasture fields were significantly lower than the current concentration in the reference wetland with average values of 8 g kg-1 and 36 g kg-1 and 180 g kg-1 and 257 g kg-1, respectively. In 2002, wetland soils have higher concentrations of FeMn-P (42.7 mg kg-1), Al-P (436.1 mg kg-1), and CaMg-P (42.2 mg kg-1) than their levels in pasture soils of 10.6, 171.6, and 10.5 mg kg-1, respectively. The levels of water soluble P and NH4-P were comparable between wetland soils and pasture soils.