How to calculate the light a crop is receiving in the greenhouse

Light Conversions in the Greenhouse

When working inside a growing system such as a greenhouse or a plant factory system we must have enough knowledge about light management. When we understand light we can make smart decisions to promote the best environmental conditions to promote growth, development and yield in our crops.

This article has the purpose to guide you on the approach you can take when working inside of greenhouses to correctly calculate the amount of light your crop is receiving.

What is Solar Radiation or Global Radiation?

To understand light, let’s first separate light from solar radiation definition. Solar radiation in Earth covers a range 300 to 1500 nm. Solar radiation includes more than light. Only 45% to 50% of solar radiation represents light, the rest of the wavelengths include UV radiation and heat. To measure radiation we use energy units like Joules/m2/s or W/m2.

Which is the best way to measure light in order to understand the impact of light in crops?

Light included in solar radiation includes all wavelengths visible to the human eye. In order to understand how plants use light we use PAR (Photosynthetic Active Radiation). PAR includes just a portion of solar radiation, from 400 nm to 700 nm. When measuring PAR we use a specific unit called PPFD (Photosynthetic Photon Flux Density) measured in