State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry of Atmospheric Physics Academy of Sciences(CAS) 100029.R.China;
College of Earth and Planet Science of Chinese Academy of Sciences 100049.R.China;
College of Resources and Environmental Sciences Agricultural University 100193.R.China;
School of Ecology and Environment Mongolia University 010021.R.China;
CAS Key Laboratory of Forest Ecology and Management of Applied Ecology Academy of Sciences 110164.R.China;
College of Tropical Crops University 570228.R.China;
N2 fluxes; 15N gas-flux method; N2O/(N2O+N2)ratios; detection limit; intensive cropping system;