Optical and photonic technologies have found many applications in agriculture, from soil and crop analysis to deciding the most opportune time for watering or harvesting via plant growth with special lighting and automatic cow milking etc. Let us describe a few of these applications in more details:

  • Soil health analysis: soil health is often indicated by soil bulk density. Low bulk densities indicate more organic matter and therefore more nutrient-rich soils. Using 3D-laser scanning, one can determine the volume of grains of soil and together with their weight determine their density. Soil health is also sometimes analysed through multi-spectral imaging from airplanes.
  • Crop analysis: Maybe the oldest optical technique used to analyse crop quality is the grape wine refractometer used to measure the concentration of sugar in the juice of grapes. Optical spectroscopy is used in many different ways, e.g. to measure the nitrogen level in leaves or grains or to identify levels of bruising in fruits and vegetables. 
  • Controlling watering: Lasers and telescopes are used in optical farming to detect evapotranspiration and help farmers decide when to irrigate. The system is based on computer-controlled analysis of the scintillation induced by the evapotranspiration.
  • Plant growth stimulation through smart lighting: Efficient lighting can help controlling plant growth and quality. It is apparently possible to reduce the energy consumption by as much as 50% and at the same time produce healthier plants by controlling spectrum, intensity and timing.
  • Automatic cow milking and milk analysis: Imaging or even simpler systems based on lasers and detectors can be used to control the automatic milking of cows ensuring the proper flow of the cows along the milking chain. At the same time, optical spectroscopy can be used to on-line measure the quality of the milk.