Abstract: Increased atmospheric CO₂ supply is predicted to alter plant growth and the nutrients level. It is not clear whether the biomass of winter wheat in rice-wheat rotation system is still increased and more nitrogen application is necessary. The biomass and N uptake were studied at two concentration of CO₂[Ambient and Elevated(Ambient+200μmol·mol^-1)] and at low and normal nitrogen levels (LN,150 kg N·ha^-1 and NN, 250 kg N·ha^-1) for winter wheat. Growth and N uptake responses of winter wheat at four growth stages were determined. Results showed that the biomass of different parts of wheat increased by 28.3%-44.5% averagely. The response of biomass was significant and the increase degree was the largest at jointing stage. Under LN and NN conditions, the biomass for leave, shoot, ear and root increased significantly by 36.8%,40.9%,91.2% and 53.2%, 89.4%,52.2%, 55.5% and 67.9%, respectively. Moreover, ... ...

Key words: Atmospheric CO₂ concentration, Winter wheat, Growth analysis, Nitrogen uptake