HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Simpson, R. T. Articles by Thiet, R. K. Search for Related Content PubMed Articles by Simpson, R. T. Articles by Thiet, R. K. Agricola Articles by Simpson, R. T. Articles by Thiet, R. K. Related Collections Carbon Sequestration Microbial Processes Soil Organic Matter

Preferential Accumulation of Microbial Carbon in Aggregate Structures of No-Tillage Soils

^a Dep. of Natural Resources, Univ. of New Hampshire, Durham, NH 03824
^b Dep. of Agronomy and Range Science, Univ. of California, Davis, CA 95616

View larger version (27K): [in a new window]   Fig. 1. Aggregate separation scheme. Fractionation I involved wet sieving air-dry soil into four aggregate-size classes. In fractionation II, small macroaggregates (250–2000 µm) were further separated into coarse sand and POM (>250 µm), microaggregates (53–250 µm) and the silt and clay fraction (<53 µm).

View larger version (22K): [in a new window]   Fig. 2. Total amino sugar C (g m–2) at 0 to 5 and 5 to 20 cm in conventional tillage (CT) and no-tillage (NT) soils at Horseshoe Bend, GA. There was a significant difference (P < 0.05) between NT and CT at the 0- to 5-cm depth for all three amino sugars. Inset: Total amino sugar C in the plow layer (0–20 cm).

View larger version (17K): [in a new window]   Fig. 3. Contribution of aggregate-size classes to whole soil amino sugar C (mg kg–1 whole soil) in surface soil (0–5 cm) of (A) conventional tillage (CT) and (B) no-tillage (NT) soils at Horseshoe Bend, GA. Bars with different letters are significantly different (P < 0.05) across aggregate size classes for a given amino sugar. An * indicates a significant difference between CT and NT within an aggregate size class and amino sugar.

View larger version (13K): [in a new window]   Fig. 4. Amino sugar C in macroaggregate-derived size classes on a whole soil basis for (A) conventional tillage (CT) and (B) no-tillage (NT) soils at Horseshoe Bend, GA (0–5 cm depth). Bars with different letters are significantly different (P < 0.05) across aggregate size classes for a given amino sugar. An * indicates a significant difference between CT and NT within an aggregate size class and amino sugar.