Background: Managed temperate grassland has the potential to sequester carbon if management practices are improved. In this study, CO2 flux was measured by the eddy covariance technique in two identical temperate sown grasslands under different managements, viz. mowing and grazing, to estimate and compare net carbon storage under both the management systems. Results: In both mowing and grazing systems, the averaged annual gross plant productivity, ecosystem respiration and net ecosystem exchange were -1720 and -1741, 1244 and 1510, and -476 and -231 g C m-2 year-1, respectively. Although the management practices did not significantly influence gross plant productivity (p > 0.05), grazing system increased Reco significantly by 21% (p < 0.05) but reduced net ecosystem exchange by 52% (p < 0.05) compared to mowing system. However, averaged annual net carbon storage were 23 and 141 g C m-2 year-1 under mowing and grazing, respectively. Conclusion: The results indicate that temperate sown grassland has the potential to sequester carbon under grazing.