Spatial Variability of Soil Properties: Interactions Between Topography and Management.

Spatial variability of soil carbon (C) is an important factor to consider in large scale estimations of soil C stocks and in assessments of the effects of different land use and management practices on them under changing climate. In undulating landscape of the U.S. Midwest topography is one of the major drivers behind field scale variability of soil C. The overall topographical effects on soil C have been well documented, however, the fact that topography can influence not only the overall C levels, but also can affect the influence of land use and management practices has been less recognized. In this talk I will address interacting influences of topography and management on spatial variability patterns of total soil C levels and specific C pools as well as on long-term changes in total C at different depths. I will also discuss importance of accounting for topography/management interactions in deriving large scale C estimates and in designing and analyzing data from field experiments.