施氮量对高产小麦光合特性、干物质积累分配与产量的影响

为明确山东省高产麦区高产节肥高效的施氮量,以高产小麦品种济麦22和烟农1212为材料,在大田试验测墒补灌条件下,设置0(N0)、180(N1)、210(N2)、240 kg·hm~(-2)(N3)四个施氮量水平,研究施氮量对小麦旗叶光合特性、干物质积累分配和籽粒产量的影响。结果表明,适量施氮可显著提高灌浆中后期旗叶的叶绿素相对含量、净光合速率、蒸腾效率和气孔导度,增加拔节期至成熟期小麦的干物质积累量,提高干物质在籽粒中的分配量及其对籽粒产量的贡献率;与不施氮肥处理相比,施氮180～240 kg·hm~(-2)时,济麦22增产10.1%～28.2%,烟农1212增产27.1%～42.8%。在同一施氮处理下,开花期至成熟期,烟农1212的干物质积累量比济麦22高12.77%～19.92%;花后14～28 d,烟农1212的旗叶净光合速率比济麦22高8.61%～24.11%;灌浆期间,烟农1212花前营养器官贮藏干物质向籽粒的转运量比济麦22高6.10%～11.68%,花后光合同化物积累量比济麦22高12.63%～22.00%,籽粒产量增加12.73%～19.46%。说明适量施氮有利于灌浆中后期小麦旗叶保持较高的光合性能,促进花后光合同化物的积累和向籽粒的分配,发挥品种的高产潜力。当施氮量为210 kg·hm~(-2)时,济麦22和烟农1212的籽粒产量、氮肥农学效率和氮肥偏生产力均最高,是该试验条件下的最优施氮量。

Effect of Nitrogen Application Rateon Photosynthetic Characteristics,Dry Matter Accumulation and Distribution and Yield of High-Yielding Winter Wheat

To explore the rational nitrogen(N) application rate for higher yield and fertilizer use efficiency in high-yielding winter wheat areas in Shandong province,two high-yielding wheat varieties(Jimai 22 and Yannong 1212) were selected and treated with 0(N0),180(N1),210(N2),and 240(N3) N fertilizer levels,to study the effects of N rate on the photosynthetic characteristics of flag leaf,dry matter accumulation and distribution,and yield under supplemental irrigation based on measuring soil moisture in the field experiment. The results showed that appropriate N application significantly increased the SPAD,net photosynthetic rate(P_n),transpiration rate(T_r) and stomatal conductance(G_s) of flag leaves in the middle and late grain filling stages,increased the dry matter accumulation from jointing stage to maturity stage,and increased the allocation of post-anthesis assimilates stored in vegetative organs to grain and the contribution to grain. Compared with N0 treatment,N fertilizer rate of 180,210 and 240 kg·hm^-2 increased the yield of Jimai 22 by 10.1%-28.2%,and that of Yannong 1212 by 27.1%-42.8%. Compared with Jimai 22 under the same N fertilizer treatment,the dry matter accumulation of Yannong 1212 increased by 12.77%-19.92% from flowering to maturity; the P_n of flag leaves increased by 8.61%-24.11% during 14-28 d after anthesis; the translocated of pre-anthesis reserves of vegetative organs into grain increased by 6.10%- 11.68%during filling; the allocation of post-anthesis assimilates stored in vegetative organs to grain increased by 12.63%- 22.00%,and the grain yield increased by 12.73%-19.46%. It can be concluded that rational N application was beneficial to maintain the higher photosynthetic performance of flag leaves at middle and late filling stages,promoted the accumulation of dry matter and the distribution to grain after anthesis,so as to achieve the high yield of wheat varieties. Under N2 treatment,both Jimai 22 and Yannong 1212 gained the highest yield of 8 995.08 kg·hm^-2 and 10 369.50 kg·hm^-2,respectively,and achieved the highest nitrogen agronomic efficiency and nitrogen fertility.The optimal nitrogen application rate was 210 kg·hm^-2under the experimental conditions.