Manipulating the Crop Environment

Windbreaks are structures that reduce wind speed and may affect turbulence in the protected zone. The maximum efficiency is obtained with windbreaks of medium porosity that reduce wind speed up to a distance 20–25 times their height. Windbreaks promote larger temperature oscillations, which may increase frost risk and dew deposition. Soil temperature can be modified by changing its exposure to radiation, artificial heating, or mulching. Mulches can be natural (e.g., crop residues) or artificial, most notably plastic films. The crop canopy may be cooled down with sprinkler irrigation when VPD is high. Additional environmental control may be performed with row covers and greenhouses that create a warmer wind-protected environment and are increasingly popular in horticultural production.