Key Points:
- The GreenSeeker® (the NIR crop sensor used in this project) was used to take crop reflectance measurements from the crop canopy, which it converts to an index called the normalised difference vegetative index (NDVI).
- The accuracy of NDVI in relation to canopy nitrogen uptake and biomass was assessed.
- There was a strong relationship between NDVI and total nitrogen (applied + soil N), above ground crop biomass and crop N uptake. This suggests the crop sensor will be a valuable tool in crop nitrogen management.
- Further research is needed to construct the algorithm to calculate N fertiliser required to maximise yield from specific sensor measurements.
- Further work is also necessary to find out if calibrations are needed for different cultivars, soil types, regions etc.