Microbial Community Profiles and Activities among Aggregates of Winter Fallow and Cover-Cropped Soil

Soil Science Society of America JournalVolume 66, Issue 1 p. 142-153 Division S-3 - Soil Biology & Biochemistry Microbial Community Profiles and Activities among Aggregates of Winter Fallow and Cover-Cropped Soil Mary E. Schutter, Mary E. Schutter Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523Search for more papers by this authorRichard P. Dick, Corresponding Author Richard P. Dick Richard.Dick@orst.edu Dep. of Crop and Soil Science, Oregon State Univ., Corvallis, OR, 97331Corresponding author (Richard.Dick@orst.edu)Search for more papers by this author Mary E. Schutter, Mary E. Schutter Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523Search for more papers by this authorRichard P. Dick, Corresponding Author Richard P. Dick Richard.Dick@orst.edu Dep. of Crop and Soil Science, Oregon State Univ., Corvallis, OR, 97331Corresponding author (Richard.Dick@orst.edu)Search for more papers by this author First published: 01 January 2002 https://doi.org/10.2136/sssaj2002.1420Citations: 96 Published as Paper No. 11590 of the Oregon Agric. Exp. Stn., Oregon State Univ., Corvallis, OR. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Microorganisms and their activities can be heterogeneously distributed among soil aggregates, and their distribution may change in response to management practices that affect aggregate formation. In this study, aggregates of a winter fallow and winter cover-cropped soil were analyzed over time for microbial biomass (MBC), respiration, and N mineralization potential. Communities were characterized across aggregate sizes according to their extractable fatty acid methyl ester (FAME) profiles and Biolog substrate utilization patterns. Size distribution of soil aggregates and total N in aggregates changed over time. The percentage of the largest aggregate size fraction (2.0–5.0 mm) declined from March to August, whereas the percentage of 0.25- to 2.0-mm aggregates increased. For aggregates <2.0 mm, total N was greatest in July compared with other sampling dates. Cover crop residues enhanced MBC, respiration, and N mineralization in whole soils and aggregates, and shifted microbial community FAME profiles. Microbial respiration, MBC, and N mineralization were greatest in the intermediate aggregate size fractions, although specific distribution patterns changed over time or in response to cover crops. Community FAME structure was correlated with total C and N, MBC, respiration, and N mineralization potential. Some FAMEs, including i17:0, 10Me16:0, 19:0 cy, and 18:2ω6c, varied among soil aggregates, and communities were classified according to aggregate size class by canonical discriminant analysis. Community Biolog substrate utilization patterns changed over time but were not affected strongly by aggregate size. Lack of community differentiation may be due to the frequent mixing of soil during cultivation and tillage events, whereby microbial communities become evenly distributed among soil aggregates. Citing Literature Volume66, Issue1January 2002Pages 142-153 RelatedInformation