Originally Posted by Skipster
I've known Doug for quite a while. His major professor was my college roomate. Anyhow, these recommendations aren't much different from Wayne Kussow's recommendations in the 1970s. They differ a little from other research sites only in timing, such that it gets cold earlier in Madison than it does in Columbus.
But, you'll have to read their research paper. I don't agree with the controlled release source, though, because all controlled release sources are tied back to temperature -- either microbially degraded (the speed of which depends in part on temperature) or is totally temperature dependent. So, you put this fertilizer product in the environment without release, so it is subject to all sorts of different fates, including runoff loss. Since none of your fert will release from controlled release sources in the winter and could be lost ro runoff, I would just save that fert until spring.
Also, fall fert doesn't create carbohydrates in roots directly. Fall applied N allows chlorophyll to be regenerated at higher rates than no N, and it is the chlorophyll that makes the carbohydrates through the photosynthesis process. Remember, grasses in the upper midwest (WI, MN) are typically photosynthetically active until covered with snow.
Again, Soldat found that 70% of your fall N should be applied before the first frost, with the rest to come not long after.
I latched on to this very practical statement rather quickly.
As a lawnsman here in SW Ohio, I have been, for years, intentionally not lowering my cutting heighth at the "end of the season", as so many do.
The turf that I service, as I write this, is still very green and healthy, even after the blistering drought this season.
The photosynthesis part only makes sense as the sun sinks lower in the late fall sky.