Sensors

Ambient temperature and relative humidity at canopy or row level.

Carbon dioxide concentration in greenhouse air.

Photosynthetically active radiation (400–700 nm).

Infrared surface temperature of the plant canopy.

Surface moisture on leaves and free water duration.

Volumetric water content, electrical conductivity, and temperature in growing media.

Volumetric water content in field soil at root depth.

pH of irrigation water, nutrient solution, or return drain.

Electrical conductivity of nutrient solution.

Dissolved oxygen in nutrient solution.