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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.

To explore the effects of vertical rotary tillage(VR)on soil compaction during the wheat growth periods, the effects of VR(30 cm±5 cm)and traditional rotary tillage(TR,12 cm±5 cm)under no fertilization(nF)and fertilization(F)levels, respectively, on wheat grain yields, nitrogen use efficiency, and soil compactions during two consecutive seasons(2017-2018 and 2018-2019)were studied. The results showed that VR increased wheat yield, improved nitrogen use efficiency, decreased soil compaction, and improved soil productivity compared to TR. Compared with nFTR treatment, FVR and FTR treatment related grain yield increased by 50.16% and 36.28%, respectively, in 2018 and by 42.91% and 34.79%, respectively, in 2019. Nitrogen agronomic efficiency of FVR increased by 38.29% in 2018 and 23.35% in 2019 compared with FTR. Partial factor productivity of nitrogen for FVR treatment increased by 10.15% in 2018 and 6.02% in 2019. Compared to TR, VR significantly reduced soil compaction in the 10 cm soil layer depth at the elongation stage and filling stage in the first season. However, there were no significant differences between the two tillages in the following season. VR tillage could also reduce soil compactions in the 20 cm soil layer depth at the elongation stage, and significantly reduced soil compaction under fertilizer conditions. Additionally, there were no significant differences between the two tillage for soil compactions in the 5 cm soil depth layers. VR could effectively decrease soil compaction in the 10 cm soil layer depth at the wheat elongation and filling stages, constructed better soil structures, and increased wheat grain yields and nitrogen agronomic efficiency.