番茄叶片叶绿素吸光度与施氮水平相关性研究

Relations between Chlorophyll Absorbency of Tomato Leaves and Nitrogen Levels

为了揭示番茄叶片叶绿素光谱特征与番茄施氮量之间的关系,采用能够严格控制施肥量的营养液培养法,应用近红外光谱技术结合化学计量学方法研究不同氮浓度对温室番茄叶片叶绿素光谱特性的影响。结果表明,在0～20mmol·L-1范围内,随着营养液中氮浓度的增加,番茄的叶片叶绿素吸光度值增大,在20mmol·L-1时达到最大值;在20～30mmol·L-1范围内,随着营养液中氮浓度的增加,番茄的叶片的吸光度值减小。叶绿素吸光度值与施氮量呈二次多项式变化关系。这说明在适宜浓度范围内,氮浓度的增加有利于叶绿素含量的增加;但过量的氮肥处理有可能抑制植株的生长发育,造成叶绿素含量的减少。

In order to reveal the relationship between chlorophyll spectral features and nitrogen levels, the effects of dif- ferent nitrogen concentrations of nutrient solution on spectral characteristics of tomato leaves were studied using visible and near infrared（Vis/NIR） spectroscopy in hydroponics in asymmetrical multi-span greenhouse. The results showed that, in 0~20 mmol ~ I.-1 range, the absorbency of tomato leaves chlorophyll increased with the increasing of the ni- trogen concentration; at the 20 mmol~ L 1 reached maximum; In the 20~30 mmol ~ L 1 range, it decreased with the increasing of the nitrogen concentration. The relation was a quadratic polynomial between chlorophyll absorbency and nitrogen level. It concluded that, in appropriate concentration range, the increase of nitrogen concentration was beneficial to deposit of chlorophyll. However, too much nitrogen treatment could inhibit plant growth and development, and caused the chlorophyll decreased.