冬小麦光合速率对施氮量与光照强度的响应分析

为了探索施氮量在不同光照强度下对冬小麦光合速率的影响,基于小区施氮控制试验,设置4个施氮量水平和5个光照强度,分析施氮量对冬小麦叶片氮素含量的响应规律,研究光照强度和叶片氮素对冬小麦叶片净光合速率的影响。结果表明,随施氮量的提高,叶片含氮量逐渐上升,过量施氮会抑制灌浆初期和灌浆中期叶片含氮量的增加;从拔节期-灌浆中期,叶片含氮量总体降低,冬小麦净光合速率随光照强度的增大呈增加趋势,光合速率在低施氮量下先上升后下降,而在不施氮和中、高施氮量下随生育时期推进呈下降趋势;在人工控制的固定光照强度下,冬小麦叶片净光合速率与叶片含氮量呈极显著正相关,即随着叶片含氮量的增加光合速率呈上升趋势,故适量增施氮肥有助于冬小麦光合速率的提高。

The Response Analysis of Photosynthetic Rate of Winter Wheat to Nitrogen Application Rate and Light Intensity

In order to explore the effect of nitrogen application rate on photosynthetic rate of winter wheat under different light intensities,the study was based on the nitrogen control test of research plots,and four levels of nitrogen application and five light intensities were set to analyze the response of nitrogen fertilizer to nitrogen content of winter wheat leaves and to study the effects of light intensity and leaf nitrogen on the net photosynthetic rate of winter wheat leaves.The results showed that leaf nitrogen content gradually increased with the increased of nitrogen application rate,excessive nitrogen application could inhibit the increase of leaf nitrogen content at the beginning of grain filling and mid-grain filling.From jointing to mid-grouting stage,leaf nitrogen content had been declining generally,and the net photosynthetic rate of winter wheat increased with the increased of light intensity.The photosynthetic rate increased first and then decreased at low nitrogen application rates,while in the absence of nitrogen and medium and high nitrogen application with the growth period the photosynthetic rate showed downward trend.There was a significant positive correlation between net photosynthetic rate and leaf nitrogen content under the artificially controlled fixed light intensities,and the photosynthetic rate increased with the increased of nitrogen content.Therefore,a moderate application of nitrogen fertilizer in winter could increase the photosynthetic rate of winter wheat.