My series of photos show a contrast of two soil samples taken side by side. These two areas receive irrigation from the same irrigation heads.
When we find this type of situation, obviously we must hand water, but we also turn to other tools to help out. Marco is shown watering these areas with a device on the hose that can contain a "pellet" of wetting agents. Certain wetting agents help remove the organic acid coating on the soil particles which contribute to the hydrophobicity. The pellet is much like a soap, helping water get into the soil by breaking water tension. Some wetting agents are designed to help hold water in certain situations. The array of products have become difficult to dissect, so the USGA and Michigan State University helped out with this research http://gsrpdf.lib.msu.edu/ticpdf.py?file=/article/zontek-understanding-7-20-12.pdf
With all of the science and experience supporting us, there is still no magic bullet. Since each course has a unique soil structure and water chemistry, each Golf Course Superintendent is on his/her own to determine what works for the property they steward.
Have a great day, they are now getting shorter,
Sent from Erwin's phone, please excuse grammar and punctuation.