本文在大田条件下以不施氮为对照(CK),设置传统施肥(FP)、水肥一体化(WF)以及水肥一体化减氮20%(WF-N)共4种水氮管理模式,研究不同氮肥用量及施氮方式对玉米产量形成、氮素吸收及其利用效率的影响。结果表明同等施氮量下,水肥一体化施氮可显著提高玉米籽粒产量、穗粒数、千粒重和完熟期群体干物质积累,较FP处理分别增加9.57%、7.45%、2.41%和9.14%；生育后期叶片氮素含量、穗位叶光合速率(Pn)显著高于FP处理；抽雄后氮素同化量(AANAS)及其对籽粒的贡献率(NACP)均显著增加,完熟期群体氮素积累量较FP处理增加8.77%；氮肥偏生产力(PFPN)、氮肥农学效率(AEN)、氮肥利用率较FP处理分别增加9.57%、45.28%、28.65%。减氮20%条件下,水肥一体化施氮的玉米籽粒产量、穗粒数、千粒重、完熟期群体干物质积累量和叶片氮素含量、Pn以及AANAS、NACP、完熟期群体氮素积累量与FP处理均无显著差异,但其PFPN、AEN、NUE较FP处理分别增加24.34%、21.87%和21.38%。水肥一体化施氮增产增效的主要原因是显著增加了玉米生育后期氮素积累量,有效提高了玉米生育后期叶片氮素含量和光合性能,为籽粒充实提供了充足的光合产物。因此,同等施氮条件下,水肥一体化可以显著增加干物质积累量和生育后期叶片氮素含量,改善光合性能,促进植株氮素的吸收,增加生育后期氮素同化量,进而提高籽粒产量和氮素利用效率；减量20%施氮条件下,仍能获得与传统施肥方式相当的籽粒产量,但是氮素积累量和氮素利用效率显著提升。水肥一体化下氮肥适度减量是夏玉米高产高效的有效技术途径。
英文摘要:
We set four water and nitrogen managements in the field: non-nitrogen (CK), famer practice (FP), water and fertilizer coupling (WF) and 20% reduction of nitrogen of water and fertilizer coupling (WF-N). We studied the effect of different nitrogen supply methods on grain yield, nitrogen uptake and NUE of summer maize, providing technical support for high yield and efficiency of summer maize. Compared with FP treatment, under the same nitrogen application rate, the grain yield, grains per ear, 1000-kernel weight and dry matter accumulation at the mature stage of WF treatment increased by 9.57%, 7.45%, 2.41% and 9.14%, respectively. Leaf N content and photosynthesis rate (Pn) of water and fertilizer coupling treatment were significantly higher than those of FP treatment in later growing period. Compared with FP treatment, assimilation amount of nitrogen after silking (AANAS) and nitrogen assimilation contribution proportion (NACP) increased significantly, and the nitrogen accumulation at the mature stage increased by 8.77%, and partial factor productivity from applied nitrogen (PFPN), agronomic efficiency of applied nitrogen (AEN), and NUE increased 9.57%, 45.28% and 28.65%, respectively. There was no significant difference between WF-N and FP treatment in the grain yield, grains per ear, 1000-kernel weight, and dry matter accumulation, leaf N content, Pn, AANAS, NACP and the accumulation of nitrogen at mature stage. In the meanwhile, PFPN, AEN, and NUE of WF-N treatment increased by 24.34%, 21.87% and 21.38%, respectively, compared with FP treatment. Water and fertilizer coupling treatment increased grain yield and NUE due to the significant increase of nitrogen accumulation in late growth period, the effective improvement of leaf N content and Pn in late growth period, and sufficient supply of photosynthetic products for grain filling. Under the same amount of nitrogen application condition, the integration of water and fertilizer coupling significantly increased dry matter accumulation and leaf nitrogen content, improved photosynthetic characteristics, promoted plant nitrogen absorption, and increase AANAS, and then further increased grain yield and NUE. Under the condition of reducing 20% nitrogen application rate, the grain yield still remains the same level as the farmer practice. However, N accumulation and NUE were significantly improved. So, the appropriate reduction of nitrogen rate was an effective technique for high yield and high efficiency of summer maize under water and fertilizer coupling.
查看全文
;
