What is the most efficient means of crop irrigation?

Is it drip irrigation?

Thanks,
Rob

Define efficient.

My system with capillary plastic tubing to each major root branch is extremely good at conserving water, but it might be a bit labor and material intensive.

Efficient in terms of water usage.

A system which delivers metered amounts of water to each plant between the hours of 12am - 7am is the most efficient. If the system is able to detect the dampness of the soil and switch off that is even better. Overwatering is wasteful and waterlogged roots lead to sick plants.

The ground temperature rises during the day so water applied then partly evaporates which is why night watering is best.

As long as you are not getting the foliage wet. Wet foliage at night can lead to fungus growth.

A buried soaker hose, run after sunrise.

I believe plants only transpire when during daylight.

A soaker wets more soil, encouraging root growth into those areas.

You can also use a buried soaker during high sun periods when necessary, when a sprinkler would cause water burns on the plants.

I am sorry, I forgot to mention I was thinking of commercial agriculture rather than gardening.

Thanks,
Rob

A very long soaker hose …
Timing may be more important than the mechanism.

Just not true. Old wive’s tale that refuses to die.

http://puyallup.wsu.edu/~linda%20chalker-scott/Horticultural%20Myths_files/Myths/Leaf%20scorch.pdf

That has not been my experience, but it does not matter, if one waters at soil level.

Seasonal rain-fed for rice. Your main problem is looking for something to do while the grain matures.