分期追施氮肥对玉米营养器官中非结构性碳水化合物积累转运及产量的影响

在位于陇东旱塬区的陇东学院试验农场进行田间试验,研究追肥时期对玉米营养器官中非结构性碳水化合物(NSC)积累转运变化及产量的影响。结果表明,从小喇叭口期至成熟期,玉米叶片中NSC含量呈倒"V"的变化动态趋势,追肥时期仅改变其NSC峰值大小,不影响其变化趋势。小喇叭口期追施氮肥显著提高茎秆中NSC含量。玉米茎秆、根和叶片中NSC的转运量和转运率的变化规律相同,转运量表现为茎叶根,其转运率分别为7.72%、5.69%、2.70%。试验条件下,小喇叭口期:大喇叭口期:灌浆期为1∶2∶1的追肥方式下,玉米的产量最高,为10 177.59 kg/hm~2,较常规施肥(小喇叭口期一次追肥)增产11.86%。

Effect of Topdressing Nitrogen on Transportation and Accumulation of Non-structural Carbohydrate of Vegetative Organs and Yield in Maize

To optimize maize cultivated method in arid area, topdressing nitrogen fertilizer was applied at maize different growth stages, then the accumulation and transportation of non-structural carbohydrate(NSC) in vegetative organs of maize plant and maize grain yield were studied. Field trials were carried out on the experimental farm of Longdong University, a dryland area in eastern Gansu province, China. The results showed that leaf NSC content in control shows a dynamic trend of inverted "V" from maize small bell stage to mature stage. The peak value of NSC is changed by topdressing, but the dynamic trends of NSC is not affected. NSC content in stems is significantly in-creased by topdressing nitrogen fertilizer at small bell stage. Nitrogen application at tetrad stage of pollen significant-ly increases the content of NSC in leaves. The trends of NSC transportation amount and efficiency are similar for dif-ferent vegetative organs of maize. However, NSC transportation amount of different organs is different and in the fol-lowing order:stem(13.93 g/plant) > leaves(2.78 g/plant) > root(0.04 g/plant). And transportation efficiency is 7.72%, 5.70% and 2.35% for stem, leaf and root, respectively. When topdressing nitrogen is applied as the ratio of 1:2:1 for small bell stage:pollen tetrad stage:filling stage, the highest yield of maize(10 177.59 kg/ha) was obtained, which is increased by 11.86% compared with conventional topdressing mode.