African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6693

Full Length Research Paper

Relationship between carbon and nitrogen in degraded alpine meadow soil

Li-Hua Cao1,2, He-Man Liu1 and Shi-Wei Zhao2*
  1Tibet Agricultural and Animal Husbandry College, Linzhi 860000, China.  2State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of soil and water  conservation, Northwest A and F University, Yangling 712100, P. R. China. 
Email: [email protected]

  •  Accepted: 21 June 2012
  •  Published: 17 July 2012

Abstract

 

The distribution of soil organic carbon (SOC), labile organic carbon (LOC), and available nitrogen, as 
well as, the corresponding relationships between carbon and nitrogen were analyzed among meadows 
with varying degrees of degradation (normal, slight and severe) in Dangxiong, Tibet. The increasing 
severity of meadow degradation corresponded with decreasing soil organic carbon, LOC and available 
nitrogen. The SOC distributions in the 0 to 10 cm soil layer of the slightly degraded and severely 
degraded meadows were lower than that of the normal meadow by 13.2 to 27.5% and 39.5 to 78.6%, 
respectively. The LOC distribution in the two areas decreased by 11.1 to 50.9% and by 31.2 to 77.2%. 
The corresponding available nitrogen decreased by 25.6 to 38.2% and 48.8 to 68.0%, whereas the SOC 
decreased by 6.0 to 29.7% and 53.2 to 73.2%. The degradation of soil carbon and nitrogen occurred first 
in the 0 to 10 cm layer. In the 0 to 10 cm and the 10 to 20 cm layers, the relationship between soil 
available nitrogen and LOC was more significant than that between soil available nitrogen and SOC. 
Grassland degradation caused a decrease in the ratio of soil LOC to available nitrogen. The average 
proportions of LOC and available nitrogen in the normal, slightly degraded, and severely degraded 
meadows were 24, 19, and 17. These values showed that the nitrogen loss caused by grassland 
degradation is faster than LOC loss. During degradation, organic carbon was more stable than soil 
available nitrogen.  
 
Key words: Alpine meadow, soil organic carbon, labile organic carbon, available nitrogen.