水氮互作对小麦土壤水分利用和茎中果聚糖含量的影响

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

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:0kg.hm-2(N0)、180kg.hm-2(N1)、240kg.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60mm,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180kg·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240kg·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.180kg·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.

A field experiment was conducted to study the effects of water-nitrogen interaction on the flag leaf photosynthetic rate, penuh stem fructan content, fertilizer N use efficiency, and soil water use efficiency of strong gluten wheat variety ＇ Jimai 20＇. Three N application levels （N0, 0 kg · hm^-2; N1, 180 kg · hm^-2; and N2,240 kg · hm^-2） and four irrigation schedules （W0, no irrigation; W1, irrigation before sowing and at jointing and flowering stages; W2, irrigation before sowing, before wintering, and at jointing and flowering stages ; W3, 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 N1 had a higher flag leaf net photosynthetic rate and penuh stem fructan content, and the highest grain yield, apparent N use efficiency, agronomic N use efficiency, and water use efficiency. Treatment N2 had a higher penuh stem fructan content than treatments NO and N1. N0 N application and applying excessive N did not benefit the increase of grain yield, fertilizer N use efficiency, and water use efficiency. Treatment W1 promoted the fructan accumulation in penuh stem and accelerated the translocation of the accumulated fructan to grain, being beneficial to the increase of grain yield. Treatment N1W1 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.