So, I did this experiment with one of my classes and the results are interesting and may help you keep your plants hydrated this hot summer.
We asked the question: "Will cucumber seeds germinate better if they are planted in a mound with a punctured coffee can full of water on top of the mound?" So we planted one mound like normal and for the second mound we punctured 4 very small holes in the bottom sides of a large coffee can and filled it with water. The water in the can drip-irrigated the mound. We watered both mounds daily and also filled the can daily. The mound with the coffee can germinated much quicker than the one without. I read that cucumbers do not germinate as well and can have their yield cut by as much as half if they don't have even watering as a seed. And the first claim so far seems to be true. Happy gardening!