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Priming of Soil Carbon Decomposition in Two Inner Mongolia Grassland Soils following Sheep Dung Addition: A Study Using 13C Natural Abundance Approach.
- Source :
- PLoS ONE; Nov2013, Vol. 8 Issue 11, p1-9, 9p
- Publication Year :
- 2013
-
Abstract
- To investigate the effect of sheep dung on soil carbon (C) sequestration, a 152 days incubation experiment was conducted with soils from two different Inner Mongolian grasslands, i.e. a Leymus chinensis dominated grassland representing the climax community (2.1% organic matter content) and a heavily degraded Artemisia frigida dominated community (1.3% organic matter content). Dung was collected from sheep either fed on L. chinensis (C<subscript>3</subscript> plant with δ<superscript>13</superscript>C = −26.8‰; dung δ<superscript>13</superscript>C = −26.2‰) or Cleistogenes squarrosa (C<subscript>4</subscript> plant with δ<superscript>13</superscript>C = −14.6‰; dung δ<superscript>13</superscript>C = −15.7‰). Fresh C<subscript>3</subscript> and C<subscript>4</subscript> sheep dung was mixed with the two grassland soils and incubated under controlled conditions for analysis of <superscript>13</superscript>C-CO<subscript>2</subscript> emissions. Soil samples were taken at days 17, 43, 86, 127 and 152 after sheep dung addition to detect the δ<superscript>13</superscript>C signal in soil and dung components. Analysis revealed that 16.9% and 16.6% of the sheep dung C had decomposed, of which 3.5% and 2.8% was sequestrated in the soils of L. chinensis and A. frigida grasslands, respectively, while the remaining decomposed sheep dung was emitted as CO<subscript>2</subscript>. The cumulative amounts of C respired from dung treated soils during 152 days were 7–8 times higher than in the un-amended controls. In both grassland soils, ca. 60% of the evolved CO<subscript>2</subscript> originated from the decomposing sheep dung and 40% from the native soil C. Priming effects of soil C decomposition were observed in both soils, i.e. 1.4 g and 1.6 g additional soil C kg<superscript>−1</superscript> dry soil had been emitted as CO<subscript>2</subscript> for the L. chinensis and A. frigida soils, respectively. Hence, the net C losses from L. chinensis and A. frigida soils were 0.6 g and 0.9 g C kg<superscript>−1</superscript> soil, which was 2.6% and 7.0% of the total C in L. chinensis and A. frigida grasslands soils, respectively. Our results suggest that grazing of degraded Inner Mongolian pastures may cause a net soil C loss due to the positive priming effect, thereby accelerating soil deterioration. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 8
- Issue :
- 11
- Database :
- Complementary Index
- Journal :
- PLoS ONE
- Publication Type :
- Academic Journal
- Accession number :
- 92668979
- Full Text :
- https://doi.org/10.1371/journal.pone.0078578