I heard one the other day: I was told I shouldn't be watering my plants from the top of the soil, its best to water from below in a tray and let the plants suck up the water. This stops the 'plant shit' from washing down into the roots and is more natural >>>

Considering the plants have vertical and lateral rooting it wouldn't seem too beneficial to me.

I've also heard to deprive plants of water to make them stronger and heartier....someone used the analogy of how fat and lazy a person feels after eating a big meal, which is true but if that person eats a few big meals a day they will gain a lot of weight too!