施氮量对滴灌冬小麦光合特性及产量的影响

Effects of Different Nitrogen Application Rates on Photosynthetic Characteristics and Yield of Winter Wheat under Drip Irrigation

【目的】研究不同施氮量对滴灌冬小麦光合特性及产量的影响。【方法】在大田滴灌条件下,设置180kg/hm2(N1)、240 kg/hm2(N2)、300 kg/hm2(N3)、360 kg/hm2(N4)4个施氮量处理,研究不同施氮量对冬小麦叶面积指数(LAI)、叶绿素含量(SPAD值)、光合特性及产量和产量构成的影响。【结果】随着施氮量的增加,冬小麦的LAI、SPAD值以及净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均呈"先增后降"的变化规律,在N3处理达到最大;胞间CO2浓度(Ci)呈先"先降后增"的变化,在N3处理最低。施氮量对收获穗数影响不大,但穗粒数、千粒重、总生物量和收获指数均表现为:N3>N4>N2>N1;产量以N3处理最高,为9 540.15 kg/hm2,分别较N1、N2、N4处理产量提高了24.72%、14.44%和6.23%,达显著或极显著性差异水平。【结论】冬小麦的最适施氮量为300 kg/hm2。

【Objective】To reveal the rules of different nitrogen levels on photosynthetic characteristics and yield of winter wheat under drip irrigation.【Method】The field experiment was conducted with 4 nitrogen levels： N1（ 180 kg /hm2）,N2（ 240 kg /hm2）,N3（ 300 kg /hm2） and N4（ 360 kg /hm2） for investigations of leaf area index（ LAI）,leaf SPAD,net photosynthesis rate（ Pn）,transpiration rate（ Tr）,stomatal conductance（ Gs）,intercellular CO2concentration（ Ci） and yield.【Result】The result showed that with the increasing of the amount of nitrogen,LAI,SPAD,Pn,Tr,Gs increased firstly then decreased,and reached the maximum in N3,intercellular CO2concentration（ Ci） showed and the opposite result,and reached to the lowest level in treatment N3. Nitrogen application rate had little effect on the spikes,but the grain number,grain weight,total biomass and harvest index showed N3〉 N4 〉N2 〉N1. The highest yield of 9 540. 15 kg / hm2 was under N3,which was 24. 72%,14. 44% and 6. 23% higher than those under N1,N2（ P〈 0. 01） and N4（ P〈0. 05）.【Conclusion】The suitable nitrogen quota was 300 kg /hm2 for winter wheat under drip irrigation.