As with bee keeping, there are a lot of variables for how much water you need. You need a lot more water for sandy soil than clay. Clay holds a lot of water between soil particles whereas sand does not. Plants give off water to cool their tissues, so if you have constant sun, you need more water. If you have a lot of wind, that sucks water out of the soil and plants quickly. If you live someplace with low humidity, you need more water.
Plant leaves use photosynthesis to support their metabolic process, but plant roots use respiration just like we do. The root cells ‘breath’ oxygen to live. Without O2 in the root zone, the roots die and the plant dies. Hence you don’t want to water log a garden or everything dies. You want to strike a balance between providing the roots water, but not depriving them of oxygen.
Soaker hoses are more efficient at watering plants than overhead sprinklers. You lose a lot of sprinkler water to evaporation on a sunny day. Sprinklers will also promote mildew and fungus on some foliage. Soaker hoses are better, but I’ll admit I don’t practice what I preach all the time. The giant pumpkin growers use misters throughout the day to keep their pumpkin leaves from overheating and shutting down photosynthesis.
My rule of thumb, watch the leaves of your most sensitive plants and adjust your watering until they don’t show any signs of wilting in the future.