This next season my plan is to us an under the canopy irrigation system using Dan Micro sprinkler heads. I'll be using a system very similar to giant pumpkin grower Thad Starr's. I"ve seen his setup while visiting him a couple of years ago in Oregon. It makes the watering nice in even with great coverage.
Gary "The Wiz" Grande also uses a similar watering system and says it is the best he has tried.