Effective soil management, such as mulching during the fallow season of crops, is crucial for the sequestration or emission of soil carbon (C) and nitrogen (N) in dryland cropping systems. Based on a long-term on-farm trial in the wheat dryland of the Chinese Loess Plateau, the effects of soil management regimes on wheat yield, greenhouse gas (carbon dioxide (CO2) and nitrous oxide (N2O)) emissions, and C and N balances were evaluated. The trial included five management regimes: -N (non-N input for wheat and no additional treatment in the fallow season), CK (N input for wheat and no additional treatment in the fallow season), SM (N input for wheat and soil mulching by wheat straw in the fallow season), LG (N input for wheat and soil covered by legume green manure in the fallow season), and SM + LG (SM plus LG). The results revealed that N input increased the wheat yield by 141.6% (P < 0.05), whereas the SM, LG, and SM + LG treatments significantly (P < 0.05) reduced the wheat yield by 11.4% compared with that of the CK. The CO2 fluxes from the -N and CK treatments were markedly (P < 0.05) lower than those from the SM, LG, and SM + LG treatments. The N2O fluxes from -N, CK, and SM were significantly (P < 0.05) lower than those from LG and SM + LG. Correspondingly, total CO2 and N2O emissions increased (by 46.3% and 396%, P < 0.05) with N input, but compared to CK, increases were observed only in the LG and SM + LG treatments across the two seasons. Moreover, the net primary production (NPP) was greater in the CK, SM, LG, and SM + LG treatments (averaged 6.42 t C ha(-1) yr(-1)). Net ecosystem production (NEP) was increased by the CK, SM, and SM + LG treatments (averaged 1.21 t C ha(-1) yr(-1)). Based on the input and output, the net ecosystem C was nearly balanced (averaged - 0.49 t C ha(-1) yr(-1)) under the SM and SM + LG treatments, while it demonstrated a deficit (averaged -2.85 t C ha(-1) yr(-1)) in the -N, CK, and LG treatments. The apparent N balance showed a surplus (averaged 65.0 kg N ha(-1) yr(-1)) in CK, SM, LG, and SM + LG but a deficit (- 55.5 kg N ha(-1) yr(-1)) in -N. Therefore, different management regimes during the wheat-fallow season had varying impacts on wheat yield, greenhouse gas emissions, and soil C and N balances. The practices of wheat straw mulching (SM) and covering by legume green manure (LG) showed potential in balancing soil C and N in dryland wheat production systems.