Crop nitrogen monitoring: Recent progress and principal developments in the context of imaging spectroscopy missions
In estimating N content, most papers relies on the relationship between chlorophyll and N. However chlorophyll holds very small shares of leaf N and also the contribution of N to physiological process is minor. The paper suggests to target leaf protein which could be approximate to N contents.
Reference
Berger, K., Verrelst, J., Féret, J. B., Wang, Z., Wocher, M., Strathmann, M., ... & Hank, T. (2020). Crop nitrogen monitoring: Recent progress and principal developments in the context of imaging spectroscopy missions. Remote Sensing of Environment, 242, 111758.