长期水氮互作下不同年代冬小麦的产量和光合特性

为了解不同水氮互作下不同年代推广冬小麦品种（现代品种冀麦325和20世纪70年代品种冀麦7）籽粒产量及光合特性的变化，于2017-2018年度（丰水年）和2018-2019年度（枯水年）冬小麦生长季，在长期水氮定位试验田进行了灌水量、施氮量和品种三因子裂裂区试验。主区为灌水，设生育期灌拔节水750 m·hm^-2(灌1水)和灌拔节水750 m·hm^-2 +开花水750 m·hm^-2(灌2水)；副区为氮肥，设不施氮(N0)及施氮总量为60(N1)、120(N2)、180(N3)、240(N4)和300 kg·hm^-2(N5)6个水平。结果表明，2017-2018年度，相同灌溉水平下，小麦开花期旗叶光合速率、蒸腾速率随施氮量增加均先增后减，冀麦325旗叶光合速率、蒸腾速率最大值对应的氮肥处理均为N2，冀麦7均为N3；冀麦325的产量随施氮量增加总体均呈逐渐增加的趋势，N2处理产量基本达到稳定值，再多施氮时灌1水有减产趋势，灌2水的产量增加缓慢；冀麦7的产量随施氮量增加均先增后减，灌1水时N2处理产量较高（仅低于N5），灌2水时N2处理产量最大。2018-2019年度，相同灌溉水平下，两个小麦品种籽粒产量随施氮量增加均先增后减，灌1水和灌2水时产量最大值对应的氮肥处理分别为N3和N2。在丰水年，不同年代冬小麦灌1水、灌2水的最佳施氮量均为120 kg·hm^-2；在枯水年，灌1水和灌2水的最佳施氮量分别为180 kg·hm^-2和120 kg·hm^-2。

Yield and Photosynthetic Characteristics of Winter Wheat Released in Different Ages under Long-Term Water-Nitrogen Interaction

In order to understand the changes of grain yield and photosynthetic characteristics of winter wheat varieties popularized in different years under different water and nitrogen interactions,the experiments of irrigation,nitrogen application and three factor split region of varieties were carried out in the winter wheat growth season of 2017-2018(wet year) and 2018-2019(dry year) with a modern variety Jimai 325 and a variety released in 1970s Jimai 7 as materials. The main plot is irrigation treatment,including 750 m·hm^-2(irrigation once at jointing stage) and 750 m·hm^-2(irrigation twice at jointing and anthesis stages); the sub-plot is nitrogen treatment,including no nitrogen application(N0) and total nitrogen application of 60(N1),120(N2),180(N3),240(N4) and 300 kg·hm^-2(N5). The results showed that,in 2017-2018,under the same irrigation level,the photosynthetic rate and transpiration rate of flag leaves at anthesis increased first and then decreased with the increase of nitrogen application,and the nitrogen treatment corresponding to the maximum photosynthetic rate and transpiration rate of flag leaf of Jimai 325 was N2,and those of Jimai 7 was N3. The yield of Jimai 325 increased gradually with the increase of nitrogen application; the yield of N2 treatment basically reached a stable value; and the yield of once irrigation showed a decreasing trend but that of twice irrigation increased slowly. The yield of Jimai 7 increased first and then decreased with the increase of nitrogen application; the yield of N2 treatment reached a larger value(only lower than N5),and the yield of N2 treatment reached the maximum value. In 2018-2019,the grain yield of the two wheat varieties increased first and then decreased with the increase of nitrogen application under the same irrigation level; the nitrogen application amount corresponding to the maximum grain yield was N3 under once irrigation,and N2 under twice irrigation. In wet year,the optimal nitrogen application of winter wheat in different ages were 120 kg·hm^-2 with once or twice irrigation; in dry year,the optimal nitrogen application was 180 kg·hm^-2 with once irrigation,and 120 kg·hm^-2 with twice irrigation.