They spray the field in soccer mainly to make the ball move faster and more smoothly, keep the surface cooler, and help protect players and the grass. On dry pitches, the ball can slow down or bounce more unpredictably, while a light watering can reduce friction and dust and improve playing conditions.

Why it happens

  • Faster ball roll: A damp surface lets passes and shots travel more smoothly.
  • Cooler field: Water helps lower the surface temperature in hot weather.
  • Better safety: A slightly softer surface can reduce harsh friction and some minor abrasions.
  • Grass health: Watering helps keep natural turf from drying out and becoming hard.
  • Less dust: It keeps loose dirt from blowing around.

Extra note

Sometimes it is done right before kickoff, and sometimes again at halftime, depending on the stadium and conditions. For artificial turf, spraying can also help with cooling and surface behavior, even though the grass itself is not real.

TL;DR

They do it to improve play, protect the pitch, and make conditions safer and more consistent.