- Biomass (NDVI) Greenseeker https://ww2.agriculture.trimble.com/product/greenseeker-handheld-crop-sensor
- Chlorophyll (Nitrogen) N-Tester https://www.yara.co.uk/crop-nutrition/farmers-toolbox/n-tester-bt/
- spectral analysis of the emission of fluorescent light from plants
- Manganese-Sensor https://nutrinostica.dk/Manganese.aspx,
- Phosphate-Sensor https://spectracrop.com/forside/produkt/
