Abstract: In order to achieve high yield and high efficiency production in the wheat/maize rotation system,field experiments were conducted to investigate the effects of different nitrogen management practices on the crop yield,nitrogen utilization and N apparent balance.The results indicated that,based on the farmers routine fertilization,appropriately reducing the amount of nitrogen-dressing had no significant effect on wheat yield.The application of nitrogen regulators could increase the wheat yield by 8.3%-24.6% when nitrogen rate was 195 kg/ha,and thereby improve the N partial factor productivity,N use efficiency,N agronomic efficiency and N contribute rate.In the maize growing season,compared with the treatments applied equal amount nitrogen as basal fertilizer or base-topdressing fertilizer without the addition of nitrogen regulators,the combination of nitrogen with nitrogen regulators as basal fertilizer was the best nitrogen management practice,which increased the corn yield around 7.4%-9.6% and 13.9%-16.2% when nitrogen rate was 240 kg/ha.And the N contribute rate,N partial factor productivity and N agronomic efficiency were also increased.After a period of crop rotation,the surplus amount of soil nitrogen was 63.94-126.83 kg/ha.When the total amount of nitrogen was 435 kg/ha,compared with the single application of urea,the surplus amount of nitrogen in the treatment with nitrogen regulators reduced by 27.4%-44.2%,and the application of urease inhibitor combined with nitrification inhibitor had the most obvious effect.However,when the total amount of nitrogen was 480 kg/ha in wheat/maize rotation system,N balance surplus rate was still more than 20% even combined with the application of nitrogen regulators,which might cause a serious environmental risk.

Key words: Winter wheat, Summer maize, Nitrogen regulation, Urease/nitrification inhibitor, Yield, Nitrogen use efficiency, Apparent nitrogen balance

CLC Number: 

• S158.5