Dynamic of different C and N fractions in a Cambisol under five year succession fallow in Saxony (Germany) |
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Authors: | Dirk Landgraf Christian Bhm Franz Makeschin |
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Institution: | Dirk Landgraf,Christian Böhm,Franz Makeschin |
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Abstract: | The dynamic of different soil C and N fractions in a Cambisol under succession fallow was investigated from June 1996 until May 2001. Mineral soil samples (0 – 10 and 10 – 30 cm) were analyzed for their concentrations of organic C (Corg), total N (Nt), hot water extractable C and N (HWC and HWN), and KCl extractable C and N (Corg(KCl), Norg(KCl), NH4+‐N, NO3–‐N). The values of all C and N fractions revealed a distinct depth gradient. While the concentrations of Corg increased after set aside significantly from 7.7 to 8.9 g kg–1 at 0 – 10 cm, those at 10 – 30 cm depth decreased from 7.2 to 6.1 g kg–1. Nt remained rather constant throughout the whole observation period. The HWC concentrations increased from 0.33 to 0.49 g kg–1, while HWN decreased slightly at 0 – 10 cm with time. In contrast, both HWC and HWN increased at 10 – 30 cm soil depth. HWC showed close significant correlations to Corg, and HWN to Nt as well as to NH4+‐N and NO3–‐N, respectively. In comparison to hot water‐extractable C and N, Corg(KCl) and Norg(KCl) accounted only about one tenth of those and showed a decreasing trend with time of succession. C : N ratio of the KCl fraction was in the same order of magnitude as the HWC : HWN ratio, except the last phase of the experiment where hot water extract values increased above 10. |
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Keywords: | succession fallow soil organic matter soil nitrogen hot water extractable C and N KCL extractable C and N |
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