I highly recommend you read it, as well as the GCM article linked within. Below, I’ve quoted a few passages I found relevant.
To begin the post:
There is a fine article by Karcher and Richardson in GCM about the effect of wetting agents. In the article, they point out something important:
“It is often stated that some wetting agents move water rapidly through the root zone while other products retain considerable moisture near the surface, but the data to substantiate such claims is limited.”
I have been surprised, in conversations with turfgrass managers, to learn just how prevalent that thinking is, that soil surfactants can be divided into classes that retain more water in the soil, or that act as penetrants and may reduce soil water content.
Dr. Woods ends the post with this:
The data show two things. Soil surfactant (wetting agent) applications increase the uniformity of soil moisture. Soil surfactant applications reduce localized dry spot. If there are data showing some wetting agents retain more moisture in the soil, and others make water move through the soil more rapidly, I would love to see them.
