氮肥运筹对冬小麦光合特性和产量的影响

Effect of Nitrogen Fertilizer Rate and Topdressing Stage on the Photosynthesis and Yield of Winter Wheat

本试验以济麦22和鲁麦21为材料,研究了氮肥运筹对小麦光合特性,群体透光率和产量及其构成因素的影响。结果表明,在本试验的施氮量范围内,小麦叶面积指数、旗叶光合速率随施氮量增加而增加,而群体透光率、气孔导度及胞间CO2浓度则随施氮量的增加而降低;追氮时期后移有利于减缓后期群体叶面积的下降速度,但对气孔导度、胞间CO2浓度及光合速率等的影响较小。两个品种的籽粒产量均随施氮量的增加而增加。施氮量为225kg/hm2的3个处理中,拔节期追氮处理的产量高于其它两个追氮处理。在本试验条件下,获得高产的适宜施氮量为300kg/hm2,高产主要是通过较多的单位面积穗数和穗粒数,且追氮时期后移对籽粒产量所带来的影响较小。

In order to provide the basis for high-quality and high-yielding cultivation,the effects of nitrogen fertilizer rate and topdressing stage on the photosynthesis,light transmittance of wheat canopy,yield and its＇ components of Winter Wheat were studied with two winter wheat cultivars,Jimai22 and Lumai21.The results showed that when applied nitrogen fertilizer at the rate of 0～300 kg/hm2,LAI and photosynthesis rate of flag leaf were increased with the increase of nitrogen supply,but light transmittance of wheat canopy,stomatal conductance of flag leaf and intercellular CO2 concentration of flag leaf were decreased with the increase of nitrogen supply;Delayed-nitrogen application retards leaf area decrease,but only little effects on flag leaf photosynthesis rate,stomatal conductance and intercellular CO2 concentration.Grain yield of lumai21 and jimai22 were increased with the increase of nitrogen supply,and the highest yield both two cultivars were recorded for the treatment of 300 kg N/hm2,and were achieved because large seeds per head and large number of kernels m2.Grain yield did not show significant differences between the treatments of topdressing stage.