夏大豆植株冠层主要生长指标对氮素的响应

Response of Main Growth Indexes of Summer Soybean Canopy to Nitrogen

为定量分析夏大豆植株冠层主要生长指标对氮素的响应,以‘齐黄34’为材料,于2021年夏大豆生长季开展施氮和氮钾肥运筹田间试验,通过系统分析不同施氮水平、氮钾肥运筹对夏大豆关键生育期植株冠层含氮量的影响,以及植株冠层氮积累量、叶面积指数、SPAD值、RVI值、NDVI值与植株冠层含氮量之间的内在联系,明确夏大豆植株冠层主要生长指标对氮素的响应。结果表明,一定范围内,施氮可以有效提高夏大豆开花期和鼓粒初期植株冠层含氮量,鼓粒初期钾肥的及时供应,可有促进大豆植株对氮素的吸收;鼓粒初期植株冠层含氮量、冠层氮积累量、叶面积指数、SPAD值、RVI值和NDVI值均高于开花期;植株冠层氮积累量、叶面积指数和RVI值随冠层含氮量呈指数函数增长,开花期SPAD值和NDVI值随冠层含氮量呈线性函数增加,而鼓粒初期SPAD值随冠层含氮量呈线性函数减小。冠层生长指标是反映夏大豆植株生长状况的重要参数,明确夏大豆植株冠层主要生长指标对氮素的响应,对于指导夏大豆高效生产和肥料运筹调控具有重要意义。

In order to quantitatively analyze the response of main growth indexes of summer soybean canopy to nitrogen,field experiments of nitrogen application and nitrogen and potassium fertilizer management were carried out in the growing season of summer soybean by using soybean variety‘Qihuang 34’as the material in 2021.The response of main growth indexes of summer soybean canopy to nitrogen was clarified by the systematic analysis of the effects of different nitrogen application levels and nitrogen and potassium fertilizer management on the plant canopy nitrogen content in the key growth periods of summer soybean,and the internal relationship between the plant canopy nitrogen accumulation quantity,leaf area index,SPAD value,RVI value,NDVI value and the plant canopy nitrogen content.The results showed that nitrogen application could effectively increase the nitrogen content in the summer soybean canopy at flowering stage and early stage of grain bulging within a certain range,and the timely supply of potassium fertilizer in the early stage of grain bulging could promote the absorption of nitrogen by soybean plants.The canopy nitrogen content,canopy nitrogen accumulation,leaf area index,SPAD value,RVI value and NDVI value at early stage of grain bulging were higher than those at flowering stage.Canopy nitrogen accumulation,leaf area index and RVI value increased exponentially with canopy nitrogen content,SPAD value and NDVI value increased linearly with canopy nitrogen content at flowering stage,while SPAD value decreased linearly with canopy nitrogen content at early stage of grain bulging.Canopy growth indexes are important parameters to reflecting the growth status of summer soybean plant.To clarify the response of main growth indexes of summer soybean canopy to nitrogen is of great significance to guiding the efficient production of summer soybean and the regulation of fertilizer management.