立式旋耕方式下氮肥不同减施水平对小麦品质的影响

为探究立式旋耕（30 cm±5 cm）下氮肥减施对小麦品质的影响，研究了2017—2018、2018—2019年两个小麦生长季立式旋耕下CK（300 kg N·hm^-2）与减氮10%（RF10）、20%（RF20）、30%（RF30）处理小麦品质变化，测定项目包括籽粒品质和面粉流变特性、拉伸性能等。结果表明：与CK相比，RF10处理小麦籽粒蛋白质含量当季略增，连续减施第二季则显著下降12.2%；RF20、RF30两季均下降，且RF30当季显著下降11.6%，RF20第二季显著下降11.1%。RF10、RF20湿面筋含量与CK比，当季略升，第二季下降；RF30两季均下降，且当季与CK差异显著，降幅为10.8%。氮肥减施后面粉吸水量呈增加趋势，面团形成时间呈缩短趋势；面团稳定时间与CK比均缩短，RF20、RF30与CK差异显著。RF10、RF20面团弱化度较CK均升高，RF30当季显著升高，第二季下降。RF10、RF20面粉能量值当季升高，第二季下降；RF30两季均下降。氮肥减施对籽粒容重、出粉率、拉伸阻力及延伸性等影响规律性不明显。研究表明，减施10%、20%氮肥能实现减肥不降产，对当季小麦品质影响不大，连续减施则影响小麦品质；减施30%氮肥时小麦产量有降低趋势，且品质有所下降。

The effect of vertical rotary tillage and reduced N levels of nitrogen fertilizer application on wheat grain quality characteristics

To explore the effects of reduced levels of nitrogen(N) in fertilizer under vertical rotary tillage(VR) (30 cm±5 cm) on wheat quality, the changes of wheat grain qualities under CK(N fertilizer application rate, 300 kg N hm^-2), RF10(10% reduction in N), RF20 (20% reduction in N), and RF30(30% reduction in N) treatments under VR were assessed at two seasons(2017-2018 and 2018- 2019). Compared with grain protein content of CK, that of RF10 slightly increased at the first season and significantly decreased by 12.2% at the second season. The grain protein content of RF20 significantly decreased by 11.1% at the second season and that of RF30 significantly decreased by 11.6% at the first season. Wet gluten content of RF10 and RF20 treatments slightly increased at the first season and decreased at the second season, compared with CK treatment, and that of RF30 significantly decreased by 10.8% at the first season. For all treatments, there was an increase in water absorption of flour as well as a decrease in the development time of dough, which was significant for RF30 at the first season, compared with CK. Stability time of dough also decreased for all treatments but significantly decreased for RF20 and RF30, compared with CK. The degree of softening of dough increased for RF10 and RF20; it increased significantly at the first season and decreased at the second season for RF30, compared with CK. The energy of flour increased at the first season and decreased at the second season for RF10 and RF20; it decreased at two seasons for RF30. Grain bulk density, ratio of flour yield, constant deformation tensile resistance, and extensibility were not significantly influenced by reduction in N. A 10% and a 20% reduction in N could produce similar grain yields while reducing nitrogen fertilizer input. Further reduction in N might not obviously affect grain quality at the first season but might have an adverse effect in the following year. In fact, a 30% reduction in N had adverse effects on both yield and grain qualities.