Applications of Spectral Reflectance Techniques in Northern European Cereal Production: A Review Review Article

This review describes the theory and basic principles of spectral reflectance measurements including the advantages and disadvantages of different sensing platforms either space, aerial or ground based. The use of spectral reflectance techniques for aiding decisions relating to crop establishment, weed control, crop protection and crop nutrition are discussed, indicating the uses, limitations, areas requiring further work and future potential as a commercial tool for precision agriculture. It is concluded that spectral reflectance techniques are unlikely to be used for measuring soil properties as other technologies are better suited to this application. Spectral reflectance techniques can be used to detect weeds against a soil background but with current approaches cannot reliably identify weeds at sufficiently low populations (plants m−2) in a growing crop to control commercial herbicide applications. Spectral reflectance techniques also provide useful information about the crop canopy that can be used as a component in determining the fungicide, growth regulator and nitrogen inputs to a cereal crop.