We have a photo graph in the shed at the community garden that shows how that water plume looks in our native clay soil. It seems a little more angular in the way it spreads down from the drip line so that might account for the way we space it here. Each bed has 3 to 4 emitter lines (emitters are 8 inches apart and I don't remember their rate) spaced about a foot apart.

In the spring and early summer the irrigation timer is set for two cycles a day for about 10 to 15 minutes each. This seems to keep the water nearer the surface where seeds and seedling roots are at that stage of their growth. In the height of summer, we go to one cycle a day but for 20 minutes. We get more water deeper down to encourage the plants to send their roots after it. Seems to work just fine.

Thanks for the illustration.