Coordinated improvement of yield and quality of strong gluten wheat by reducing exogenous nitrogen application

Objectives Using an annual gradient, the effect of reduced nitrogen application on the yield and grain quality of strong gluten wheat was studied, and the appropriate nitrogen application rate for achieving coordinated stability of yield and quality synergy was determined.

Methods From 2016 to 2019, the strong-gluten wheat Gaoyou 2018, Shiluan 02-1, and Shiyou 20 were used as test materials, and N application rate of 0−480 kg/hm², the nitrogen fertilizer dosage gradient was designed to decrease year by year, respectively: 120, 60 and 30 kg/hm², to study the response of strong gluten wheat yield and grain quality to nitrogen reduction and the optimum nitrogen application rate.

Results In the range of N application rate of 0−240 kg/hm², increasing nitrogen fertilizer application significantly improved the yield of strong gluten wheat; however, in the range of 240−360 kg/hm², nitrogen fertilizer had no significant effect on wheat yield. In the range of 360−480 kg/hm², the wheat yield was significantly reduced. The yield of Shiyou 20 was the highest under each nitrogen application in each year. Nitrogen fertilizer resulted in the increase of spike number per area and grain number per ear. Applying N 240 kg/hm² coordinated the balance of spike number per area, grain number per ear and the 1000-grain weight and achieved the highest nitrogen agronomic efficiency. Except for test weight and hardness, other quality indicators increased with the increase in N application rate in different years. The sedimentation, wet gluten content and stable time were markedly affected by nitrogen fertilizer and were more sensitive to nitrogen fertilizer. The comparison among cultivars showed that the quality of Shiluan 02-1 was generally better, and its grain protein and wet gluten contents, stable time and bread volume were significantly higher than those of Gaoyou 2018 and Shiyou 20. In addition, the regulation effects of nitrogen fertilizer on the main quality indexes of the three strong gluten cultivars were similar.

Conclusions Planting Gaoyou 2018 with N 270 kg/hm², Shiluan 02-1 and Shiyou 20 with N 210−240 kg/hm² in Hebei Province meets the needs of synergistic improvement in yield and quality of the wheat cultivars.