To clarify how sowing method and nitrogen (N) rate regulate dry matter (DM) and nitrogen accumulation, remobilization, and their vertical distribution within a wheat canopy, a split-plot field experiment was conducted in Zhaoxian Experimental Base of Shijiazhuang Academy of Agriculture and Forestry Sciences from 2022 to 2024. A winter wheat cultivar Lunxuan 103 was used as the test material. Two planting methods of uniform tridimensional sowing and conventional strip sowing were set up in the main plot, and four nitrogen application rates of 0, 180, 240 and 300 kg·hm-2 were set up in the subplot. At anthesis and maturity, aboveground organs were sampled by canopy layers at 20 cm intervals from top to bottom (H1-H4) to quantify DM and N accumulation, pre-anthesis remobilization amount and efficiency, and their contributions to grain. The results indicate that compared with conventional row planting, tridimensional uniform sowing significantly increased plant dry weight at anthesis, pre-anthesis DM and nitrogen transport, transport efficiency, and contribution to grain yield, while post-flowering DM, nitrogen accumulation, and contribution to grain yield were somewhat reduced. The allocation ratio of DM and nitrogen to stem and leaf sheath and leaves increased at anthesis, whereas the allocation ratio to spike rachis and glume decreased at maturity. Compared with conventional strip sowing, under uniform tridimensional sowing, the pre-flowering DM and nitrogen transport in stem and leaf sheath of layers H1 to H4 increased by 14.84% and 21.97%, 24.19% and 16.89%, 16.85% and 28.27%, 11.31% and 24.27%, respectively; for leaves, pre-flowering DM and nitrogen transport increased by 33.65% and 17.63%, 16.17% and 10.63%, 28.16% and 8.20%, and 23.81% and 22.57%, respectively. The increase in pre-flowering DM and nitrogen transport efficiency of stem and leaf sheath in different vertical layers under tridimensional uniform sowing compared to conventional strip sowing followed the order H2>H4>H1>H3 and H3>H2>H1>H4, respectively; for leaves, the increase in pre-flowering DM ranked as H3>H1>H4>H2. As nitrogen application increased, grain weight, dry matter transport, and dry matter and nitrogen transport efficiency in both planting methods first increased and then decreased, with the maximum observed under the 240 kg·hm-2 nitrogen application; post-flowering DM accumulation, grain nitrogen accumulation, and nitrogen transport generally showed an upward trend. In summary, uniform tridimensional sowing mainly promotes increases in grain dry weight and nitrogen accumulation by enhancing the redistribution capacity of dry matter and nitrogen in the middle and upper layers (stem and leaf sheath of H2 and H3) and the middle and lower layers (leaves of H3 and H4). Under the conditions of this experiment, 240 kg·hm-2 was the optimal nitrogen application rate.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |