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Agricultural land use decouples soil nutrient cycles in a subtropical riparian wetland in China.
- Source :
-
CATENA . Oct2015, Vol. 133, p171-178. 8p. - Publication Year :
- 2015
-
Abstract
- We examined the impact of human changes in land use on the concentrations and stoichiometric relationships among soil carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in a Phragmites australis riparian wetland (Minjiang River estuary, China). We compared a natural (unaltered) wetland with five altered land uses: intertidal mudflat culture and vegetable, flower, fruit and rice cultivations. All these land uses decreased C, N and K soil concentrations relative to those in the P. australis wetland. The close relationship between total soil C and N concentrations, under all land uses, suggested that N was the most limiting nutrient in these wetlands. The lower N concentrations, despite the use of N fertilizers, indicated the difficulty of avoiding N limitation in the agricultural land. Croplands, except rice cultivation, had lower soil N:P ratios than the original P. australis wetland, consistent with the tendency of favoring species adapted to high rates of growth (low N:P ratio). The release of soil C was less and the soil C:N and C:P ratios higher in the natural P. australis riparian wetland than in the croplands, whereas C storage was more similar. The levels of soil C storage were generally opposite to those of C release, indicating that C release by respiration was the most important factor controlling C storage. Cropland soil management promotes faster nutrient and C cycles and changes in soil nutrient stoichiometry. These impacts can further hinder the regeneration of natural vegetation by nutrient imbalances and increase C-cycling and C emissions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03418162
- Volume :
- 133
- Database :
- Academic Search Index
- Journal :
- CATENA
- Publication Type :
- Academic Journal
- Accession number :
- 108613355
- Full Text :
- https://doi.org/10.1016/j.catena.2015.05.003