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Full‐Inversion Tillage and Organic Carbon Distribution in Soil Profiles: A Meta‐Analysis
Author(s) -
Angers D. A.,
Eriksen-Hamel N. S.
Publication year - 2008
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2007.0342
Subject(s) - plough , tillage , soil carbon , soil science , zoology , soil horizon , total organic carbon , environmental science , soil water , mathematics , chemistry , agronomy , environmental chemistry , biology
While the adoption of no‐till (NT) usually leads to the accumulation of soil organic C (SOC) in the surface soil layers, a number of studies have shown that this effect is sometimes partly or completely offset by greater SOC content near the bottom of the plow layer under full‐inversion tillage (FIT). Our purpose was to review the literature in which SOC profiles have been measured under paired NT and FIT situations. Only replicated and randomized studies directly comparing NT and FIT for >5 yr were considered. Profiles of SOC had to be measured to at least 30 cm. As expected, in most studies SOC content was significantly greater ( P < 0.05) under NT than FIT in the surface soil layers. At the 21‐ to 25‐cm soil depth, however, which corresponds to the mean plowing depth for the data set (23 cm), the average SOC content was significantly greater under FIT than NT. Moreover, under FIT, greater SOC content was observed just below the average depth of plowing (26–35 cm). On average, there was 4.9 Mg ha −1 more SOC under NT than FIT ( P = 0.03). Overall, this difference in favor of NT increased significantly but weakly with the duration of the experiment ( R 2 = 0.15, P = 0.05). The relative accumulation of SOC at depth under FIT could not be related to soil or climatic variables. Furthermore, the organic matter accumulating at depth under FIT appeared to be present in relatively stable form, but this hypothesis and the mechanisms involved require further investigation.