2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 2
Presentation Time: 8:30 AM

Records of Anthropogenic Soil Erosion: Implications for Agricultural Sustainability

MONTGOMERY, David R., Department of Earth & Space Sciences, University of Washington, Seattle, WA 98195-1310, dave@ess.washington.edu

Differences between rates of contemporary farmland erosion and long-term soil production, or background geological erosion rates have raised concerns over the pace of soil loss since the issue was widely publicized by George Perkins Marsh in the late nineteenth century. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world. Stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and change, and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human civilizations, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability, and issue that will become increasingly relevant over the coming century.