Soil redistribution and pedologic transformations in coastal plain croplands

In agricultural basins of the southeastern coastal plain there are typicall y large disparities between upland soil erosion and sediment delivered to s treams. This suggests that colluvial storage and redistribution of eroded s oil within croplands is occurring, and/or that processes other than fluvial erosion are at work. This study used soil morphology and stratigraphy as a n indicator of erosion and deposition processes in a watershed at Littlefie ld, North Carolina. Soil stratigraphy and morphology reflect the ways in wh ich mass fluxes associated with cultivation transform the local soils. Fluv ial, aeolian and tillage processes were all found to be active in the redis tribution of soil. The soil transformations are of five general types. Firs t, erosion and compaction in the cultivated area as a whole result in the t hinning of Arenic and Grossarenic Paleudults and Paleaquults to form Arenic , Typic and Aquic Paleudults and Paleaquults. Second, redistribution of sur ficial material within the fields results in transitions between Arenic and Typic or Aquic subgroups as loamy sand A and E horizons are truncated or a ccreted. Third, aeolian deposition at forested field boundaries leads to th e formation of compound soils with podzolized features. Fourth, sandy rill fan deposits at slope bases create cumulic soils distinct from the loamy sa nds of the source area or the darker, finer terrace soils buried by the fan deposits. Finally, tillage and fluvial deposition in upland depressions re sults in the gradual burial of Rains (poorly drained Typic Paleaquults) soi ls. Results confirm the importance of upland sediment storage and redistrib ution, and the role of tillage and aeolian processes as well as fluvial pro cesses in the region. Copyright (C) 1999 John Wiley & Sons, Ltd.