氮肥运筹对滴灌冬小麦叶片光合特性及产量的影响

Effects of Nitrogen Management on Leaf Photosynthetic Characteristics and Yield of Winter Wheat under Drip Irrigation

为研究滴氮时期及滴氮比例对滴灌冬小麦旗叶生理特性及产量的影响。在总施纯氮300kg/hm^2条件下设置6个不同滴灌追氮量处理,分别用F1、F2、F3、F4、F5、F6表示,以不施氮肥为对照(F0),研究不同追施氮量对冬小麦叶面积指数(LAI)、叶绿素含量(SPAD值)、旗叶光合特性及产量的影响。结果表明,不同处理滴灌冬小麦的LAI、SPAD值变化规律一致,均呈先增后降的变化规律,LAI以F4处理相对较大,处理间SPAD值差异规律不明显;开花期、花后10d旗叶净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均表现为F5>F1>F6>F4>F2>F3>F0。而各处理胞间CO2浓度(Ci)与Pn、Tr、Gs的变化规律呈相反的趋势。籽粒产量以F5处理最高,为9 889.35kg/hm^2,分别较F0、F1、F2、F3、F4、F6处理增加23.70%、3.10%、6.52%、21.44%、7.94%、14.10%。综合分析可知,总施氮量300kg/hm^2条件下,冬小麦起身期追施123.3kg/hm^2,在孕穗期、开花期各追施41.1kg/hm^2时滴灌冬小麦的光合性能表现较好。

This study was designed to elusidate the effects of nitrogen drop period and nitrogen ratio on the physiological characteristics of flag leaf and yield of winter wheat under drip irrigation.Six different drip irrigation topdressing treatments were set up under the condition of total nitrogen application rate of 300kg/ha,which were represented by F1,F2,F3,F4,F5 and F6 along with no nitrogen as the control(F0)respectively.The effects of leaf area index(LAI),chlorophyll content(SPAD value),photosynthetic parameters and yield of winter wheat was investigated.The results showed that the changes of LAI and SPAD values of different treatments of drip-irrigated winter wheat were consistent,and they all showed"first increase and then decrease".LAI of F4 treatment was relatively large,and the difference of SPAD between treatments was not clear.The net photosynthetic rate(Pn),transpiration rate(Tr)and stomatal conductance(Gs)of the flag leaf of 10d age were F5>F1>F6>F4>F2>F3>F0.The change of CO2 concentration(Ci)and Pn,Gs in each treatment showed an opposite trend.Grain yield was the highest in F5 treatment,which was9 889.35kg/ha,which was 23.70%,3.10%,6.52%,21.44%,7.94%,and 14.10% higher than that of F0,F1,F2,F3,F4,and F6,respectively.According to the comprehensive analysis,the photosynthetic performance of winter wheat was the optimal treatment under the condition of total nitrogen application rate of 300kg/ha,topdressing of 123.3kg/ha at upstanding stage and 41.1kg/ha at booting and flowering stages under drip irrigation condition.