Stabilization/destabilization mechanisms of deep soil carbon are not well understood. A number of different controlling mechanisms are suggested; here we explore differences in microbial abundance and
community structure as a controlling mechanism. Microbial abundance and community composition with
depth was assessed at three different positions within an agricultural landscape. Microbial abundance was
significantly affected by sampling depth, while differences in community structure could be attributed to
depth, landscape position, and conditions found within the depositional position. Interestingly, substantial
biomass existed at a depth of 81cm in a buried A horizon found in the depositional position.