Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2027011 | Soil Biology and Biochemistry | 2008 | 4 Pages |
Abstract
Thirty-seven arable soil samples (0-20 cm depth) ranging in clay content from 4 to 40% and in C to N ratio from 8 to 20 were incubated at â100 hPa and 20 °C for 238 days. The CO2-C evolved during days 105-147 and days 0-238 was related to the soil C to N ratio by a power function. We hypothesized the existence of a threshold value for the soil C to N ratio below which CO2-C evolution remains constant. A soil C to N threshold value of 9.7 was estimated for both incubation periods and the function predicted that the CO2-C evolution was halved when the soil C to N ratio approached 14. Data obtained by Springob and Kirchmann [Springob, G., Kirchmann, H., 2002. C-rich sandy Ap horizons of specific historical land-use contain large fractions of refractory organic matter. Soil Biology & Biochemistry 34, 1571-1581.] showed a similar relationship, but with a C to N threshold value of 10.8. We suggest that the relationship established between the C to N ratio of a soil and its CO2-C loss during incubation represents a simple but useful measure for predicting soil C loss potentials on a more general level.
Keywords
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Life Sciences
Agricultural and Biological Sciences
Soil Science
Authors
Ingrid K. Thomsen, Bjørn M. Petersen, Sander Bruun, Lars S. Jensen, Bent T. Christensen,