Soil Water Content and Organic Carbon Availability Are Major Determinants of Soil Microbial Community Composition

• Published in: Microbial ecology Vol. 48; no. 3; pp. 424 - 430
• Main Authors: Drenovsky, R. E., Vo, D., Graham, K. J., Scow, K. M.
• Format: Journal Article
• Language: English
• Published: New York, NY Springer Science + Business Media, Inc 01.11.2004; Springer; Springer Nature B.V
• Subjects: Acid soils; Agricultural soils; Agriculture; Bacteria; Bacteriology; Biological and medical sciences; Carbon; Carbon - physiology; Community composition; Composts; Environmental factors; Fatty acids; Fatty Acids - analysis; Floods; Fundamental and applied biological sciences. Psychology; Fungi; Lycopersicon esculentum; Microbial activity; Microbiology; Miscellaneous; Moisture content; Mycology; Organic carbon; Organic soils; Oryza; Oryza sativa; Phospholipids - analysis; Rice soils; Seasonal variations; Soil - analysis; Soil composition; Soil Microbiology; Soil microorganisms; Soil organic carbon; Soil types; Soil water; Soil water content; Soils; Tomatoes; Water - analysis; Water content; Origin; Monocotyledones; Biological marker; Phospholipid; Lipids; Environmental factor; Cereal crop; Fungi; Oryza sativa; Gramineae; Dicotyledones; Angiospermae; Lycopersicon esculentum; Bacteria; Solanaceae; Microbial community; Thallophyta; Data analysis; Soil moisture; Method; Fatty acids; Soils; Clinical management; Vegetable crop; Spermatophyta; Organic amendment
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-003-1063-2

Exploration of environmental factors governing soil microbial community composition is long overdue and now possible with improved methods for characterizing microbial communities. Previously, we observed that rice soil microbial communities were distinctly different from tomato soil microbial communities, despite management and seasonal variations within soil type. Potential contributing factors included types and amounts of organic inputs, organic carbon content, and timing and amounts of water inputs. Of these, both soil water content and organic carbon availability were highly correlated with observed differences in composition. We examined how organic carbon amendment (compost, vetch, or no amendment) and water additions (from air dry to flooded) affect microbial community composition. Using canonical correspondence analysis of phospholipid fatty acid data, we determined flooded, carbon-amended (+C) microcosm samples were distinctly different from other +C samples and unamended (-C) samples. Although flooding without organic carbon addition influenced composition some, organic carbon addition was necessary to substantially alter community composition. Organic carbon availability had the same general effects on microbial communities regardless of whether it was compost or vetch in origin. In addition, flooded samples, regardless of organic carbon inputs, had significantly lower ratios of fungal to bacterial biomarkers, whereas under drier conditions and increased organic carbon availability the microbial communities had higher proportions of fungal biomass. When comparing field and microcosm soil, flooded +C microcosm samples were most similar to field-collected rice soil, whereas all other treatments were more similar to field-collected tomato soil. Overall, manipulating water and carbon content selected for microbial communities similar to those observed when the same factors were manipulated at the field scale.