Does irrigating at night save water compared with daytime?

Watering when it is cooler, at night or early morning or late evening, does reduce the water lost to evaporation compared with the heat of midday, especially with sprinklers where droplets in the air and on hot leaves evaporate fast. Cooler, calmer air also means less is blown away by wind drift on sprinklers. So for sprinkler and surface irrigation, the cooler hours are more efficient and the plant takes up water better. With drip the difference is smaller because water goes straight into the soil and very little is exposed, so timing is less critical, though cool hours still help a little. Night running also fits many farmers who get electricity for the pump at night anyway. One caution: leaving foliage wet overnight can encourage some leaf diseases on certain crops, so for those, morning watering that dries off during the day is safer. For your crop and whether night watering raises any disease risk, check with your KVK.