Effects of Nitrogen Fertilization Strategy on Grain Yield and Quality of Strong Gluten Wheat in Different Cropping Systems

Nitrogen fertilization is a key factor regulating wheat grain yield and quality formation,it is very important to establish a suitable nitrogen management strategy based on cultivar and soil for high yield and superior quality wheat production.Two field experiments were conducted using a strong gluten wheat Yannong 19 to investigate the effects of nitrogen rates and dressing date on grain yield and quality under dryland-wheat and rice-wheat cropping systems.The results showed that nitrogen rate and cropping system significantly affected grain yield and quality.Within the rate of 0～240 kg N/ha,grain yield,the number of spikes and grains per spike enhanced with increasing of nitrogen rate under two cropping systems,but grain yield was significantly higher under dryland-wheat due to higher grains per spike and 1000-grain weight than under rice-wheat.Grain protein content,wet gluten content and sedimentation value increased significantly with the increase of nitrogen rate,grain quality was much better under dryland-wheat system.Under the two cropping systems,grain yield,protein yield of Yannong 19 presented the quadratic curve with increase of nitrogen rate,which indicated that grain yield and quality could be synchronously improved within the nitrogen rate of 281.03～303.02 kg/ha for dryland-wheat and 251.26～280.24 kg/ha for rice-wheat.Further more,grain yield,spikes and grains per spike were enhanced in nitrogen dressing at jointing and booting stage,and grain protein content,wet gluten content and sedimentation value were obviously improved.Nitrogen dressing date from jointing to booting stage for dryland-wheat and at booting stage for rice-wheat were suitable to synchronously improve yield and quality of strong gluten wheat.The above results suggest that increasing nitrogen rate and selecting optional dressing date based on different cropping system are key techniques to increase grain yield and quality in strong gluten wheat.