Soil microbial community structure is clearly linked to current plant species composition, but less is known about the legacy effects of plant species and agricultural management practices on soil microbial communities. Using microbial lipid biomarkers, we assessed patterns of com-munity-level diversity and abundance at depths of 0-10 and 10-25 cm from three hay (al-falfa/orchardgrass) and two corn plots in south
ern Wisconsin. Principal components analysis of the lipid biomarkers revealed differential composition of the soil microbial communities at the two depths. Despite similar abundance of fungi, bacteria, actinomycete, protozoa, and total microbial lipids in the hay and corn at 0-10 cm, community structure differed with a sig-nificantly higher absolute abundance of arbus-cular mycorrhizal fungi and gram-negative bacteria in the hay plots. No significant micro-bial lipid mass differences were detected be-tween the two management regimes at 10-25 cm, but the proportional dominance of bacterial gram type differed with depth. These results indicate the potential for legacy effects of an-nual and perennial cropping systems manage-ment on microbial community composition and suggests the importance of considering past land-use when initiating long-term agroecolo-
Lundquist, E.J., Scow, K.M., Jackson, L.E., Uesugi, S.L., Johnson, C.R. (1999) Rapid response of soil microbial com-munities from conventional, low input, and organic farming systems to a wet/dry cycle. Soil Biology and Biochemistry, 31, 1661-1675.
Zelles, L., Rackwitz, R., Bai, Q., Beck, T., Beese, F. (1995) Discrimina-tion of microbial diversity by fatty acid profiles of phosphol-ipids and lipopolysaccharides in differently cultivated soils. Plant and Soil, 170, 115-122.
Steenwerth, K.L., Jackson, L.E., Calderon, F.J., Stromberg, M.R., Scow, K.M. (2002) Soil microbial commu-nity composition and land use history in cultivated and grass-land ecosystems of coastal California. Soil Biology and Bio-chemistry, 34, 1599-1611.
Ushio, M., Wagai, R., Balser, T.C., Kitayama, K. (2008) Variations in the soil microbial community composition of a tropical montane forest ecosys-tem: Does tree species matter? Soil Biology and Biochemistry, 40, 2699-2702.
van der Heijden, M.G.A., Bardgett, R.D., van Straalen, N.M. (2008) The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial eco-systems. Ecology Letters, 11, 296-310.
Pankhurst, C.E., Blair, B.L., Magarey, R.C., Stir-ling, G.R., Garside, A.L. (2005) Effects of biocides and rotation breaks on soil organisms associated with the poor early growth of sugarcane in continuous monoculture. Plant and Soil, 268, 255-269.
Samac, D.A., Jung, H.G., Lamb, J.F. (2006) De-velopment of alfalfa (Medicago sativa L.) as a feedstock for production of ethanol and other bioproducts. In: Alcoholic Fuels, Minteer, S. (Editor), CRC Press, Boca Raton, FL, 79-98.
Fritze, H., Pietikainen, J., Pennanen, T. (2000) Distribution of microbial biomass and phospholipid fatty acids in Podzol profiles under coniferous forest. European Journal of Soil Science, 51, 565-573.
Jansa, J., Mozafar, A., Kuhn, G., Anken, T., Ruh, R., Sanders, I.R., Frossard, E. (2003) Soil tillage affects the community structure of mycorrhizal fungi in maize roots Eco-logical Applications, 13, 1164-1176.