水氮互作对小麦土壤水分利用和茎中果聚糖含量的影响

通过田间试验，以强筋小麦济麦20为材料，设置3个施氮水平：0 kg·hm^-2（N₀）、180 kg·hm^-2（N₁）、240 kg·hm^-2（N₂）；4个灌水处理：不灌水（W₀）、底墒水+拔节水+开花水（W₁）、底墒水+冬水+拔节水+开花水(W₂)、底墒水+冬水+拔节水+开花水+灌浆水(W₃)，每次灌水量为60 mm，研究水氮互作对土壤水分含量、旗叶光合速率、倒二茎中果聚糖含量及氮肥和水分利用效率的影响.结果表明：施氮水平为180 kg·hm^-2处理的旗叶光合速率和倒二茎中果聚糖含量较高，籽粒产量、氮肥表观利用效率、氮肥农学利用率和水分利用效率最高；施氮水平为240 kg·hm^-2处理的茎中果聚糖含量较高；不施氮（N₀）或施氮过多（N₂）均不利于小麦籽粒产量、氮肥和水分利用效率的提高.W₁水分处理促进了倒二茎中果聚糖的积累和向籽粒的转运，有利于产量的提高.180 kg·hm^-2施氮水平配合灌溉底墒水+拔节水+开花水的水氮交互处理（N₁W₁）具有较高的籽粒产量及较高的氮肥和水分利用效率，在此基础上增加施氮量或灌水量，小麦旗叶光合速率和倒二茎中果聚糖含量升高，籽粒产量无显著变化或降低，氮肥和水分利用效率降低.

Effects of water-nitrogen interaction on soil water utilization by wheat and fructan content in wheat stem

A field experiment was conducted to study the effects of water-nitrogen interaction on the flag leaf photosynthetic rate, penult stem fructan content, fertilizer N use efficiency, and soil water use efficiency of strong gluten wheat variety ‘Jimai 20’. Three N application levels (N0, 0 kg·hm-2; N1, 180 kg·hm-2; and N2, 240 kg·hm-2) and four irrigation schedules (W0, no irrigation; W1, irrigation before sowing and at jointing and flowering stages; W2, irrigation before sowing, before wintering, and at jointing and flowering stages; W3, irrigation before sowing, before wintering, and at jointing, flowering, and grain-filling stages) were designed. The irrigation amount was 60 mm each time. Among the N treatments, treatment N1 had a higher flag leaf net photosynthetic rate and penult stem fructan content, and the highest grain yield, apparent N use efficiency, agronomic N use efficiency, and water use efficiency. Treatment N2 had a higher penult stem fructan content than treatments N0 and N1. No N application and applying excessive N did not benefit the increase of grain yield, fertilizer N use efficiency, and water use efficiency. Treatment W1 promoted the fructan accumulation in penult stem and accelerated the translocation of the accumulated fructan to grain, being beneficial to the increase of grain yield. Treatment N1W1 had the highest grain yield, and higher fertilizer N use efficiency and water use efficiency. Excessive irrigation and N application increased the flag leaf net photosynthetic rate and penult stem fructan content, but decreased the fertilizer N use efficiency and water use efficiency, with no significant effects on grain yield.