|Malone, Robert - Rob|
Submitted to: International Soil Conservation Organization Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/24/1999
Publication Date: N/A
Technical Abstract: The process of soil C and N erosion and deposition across landscape sequences is poorly understood. It is important to describe the influence of erosion on the pools and fluxes of soil organic matter and plant nutrients to determine management effects on the soil C budget. Characterization of soil deposited in rills and inter-rill areas and the sediment carried in runoff waters has been contrasted with the near-surfac topsoil yielding descriptions of the erosion transport process on small watershed scales. Samples were collected from two conservation tillage watersheds in Coshocton, Ohio following convective thunderstorms in June and July 1998. These data complement long term monitoring of sediment transport and flume floor deposits. Deposits, topsoil, and sediments were measured for C and N contents and structural properties. The two watersheds showed similar trends. Averaging 11 years of runoff and flume floor sampling showed that suspended sediments from large events had highe C (2.1%) and slightly lower C/N ratio (8.0) than flume floor samples (C=1.9%, C/N=10.5) in chisel till with the same trend but higher C in no-till. These analyses are compared with that of field deposits and soil in the 0-1 cm and 0-5 cm depths. One obvious trend was the higher C/N ratios of soil samples and landscape deposits (C/N averaging between 14 and 22) when compared with flume deposits and runoff sediments (C/N averaging 8 to 11). There were no obvious differences in clay concentration among the landscape deposits and near-surface topsoil. These sampling and measurement techniques have the potential to quantify and contrast pools of C and N in organic matter transported by erosion.