Grasslands are areas where the vegetation is dominated by grasses and supports indigenous or introduced vegetation and has potential to be grazed (Adams et al. 2009). Grasslands occupy approximately 51% of terrestrial surface of the earth (Prentice et al. 1992) and the important source of atmospheric carbon dioxide (CO2) sequestration. During photosynthesis the vegetation in grassland assimilate atmosphere carbon into its tissues and part of it is added to soil as soil organic carbon (SOC).