Effects of nitrogen application patterns on yields of winter wheat and summer maize and nitrogen use efficiency

Under the field experiment condition, effects of different nitrogen application patterns on yields of wheat and maize and nitrogen use efficiency were studied during 20072009. There were six treatments including no fertilizer (CK), convention fertilizer (CON), organic complex fertilizer (OMF), controlled release fertilizer (CRF), controlled loss fertilizer (CLF) and changing basic fertilizer and topdressing regimes (CBT). There were the same amounts of nitrogen (N) application with 250 kg/ha in wheat season and 200 kg/ha in maize season in each fertilizer treatment. The results show that the dry matter accumulation and grain yields are significantly increased with all the treatments, comparing the CK, including CON, OMF, CRF, CLF and CBT. The grain yields of winter wheat are in the order: CRF CLF OMF CBT CON, which are between 107.5% and 147.4%; those of summer maize: CRF CLF OMF CON CBT, and range from 28.5% to 56.1%. Compared with CON, N partial factor productivity and N agronomic efficiency of winter wheat are increased observably by 2.25.1 kg/kg under the OMF, CLF and CRF treatments, and by 3.67.6 kg/kg for summer maize. But the CBT treatment is represented differently, it could increase in winter wheat and decrease in summer maize. In conclusion, compared with the control and conventional treatments, the OMF, CRF and CLF treatments could increase grain yield and nitrogen use efficiency, and could be taken as fertilizer types by spread and application. The CBT treatment is more appropriate N application pattern for winter wheat, while is not appropriate for summer maize in the study region.