Steve,
Sorry I haven’t answered your questions earlier, so here goes. Oh excuse the poor english I don’t use it all that much these days.
Jon,
If you don't mind, your post raises a few questions.
Why is peat environmentally questionable?
Here in europe and especially in GB there is a shortage of good peat. Most peat moors are rightly protected. Also when peat dries out isn’t it hard to get to accept water again?
When did the USGA start recommending straight sand or a soil mix?
There have been several courses where I am at the moment that have left out the peat and gone for straight sand in a similar style to the calafornia green. I am not sure that the USGA recommend this but I assume it was passed by the labs before use. I never said they recommended soil mixes but I read an article not so long back where the USGA were looking into other additives including soils. The reason given for not recommending soil mixes until now was it was very difficult to set specs for them due to the wide range.
What are "German FLL"specs?
FFL are german based specs which have a similar perculation specs to USGA but allow several different builds depending on the natural drainage of the site and the use of soil in the mix.
Why would anyone fertilize with phosphorous on an established USGA green (or any other green)? What benefit would that element provide? Even in sand greens, phosphorous is usually present in sufficent quantities for turfgrass health.
This is again maybe a european problem. In main land europe (except scandinavia) I have yet to find a company that recommends anything other than a full NPK fertiliser. In GB this is not the case but I am unaware of what the situation is in the USA. From your response it appears that you don’t use any P.
Why would push-up greens be more disease resistant than USGA?
Mainly because it has a stronger/more bio life in it (english word missing at the moment
). In the last 20 years I have mainly worked with push greens and have never had to spray fungicide or pesticides. This is in sharp contrast to many of the surrounding courses that appear to be having a constant campaign to keep their greens in some sort of shape. What is interesting is the approaches which are soil base are not effected but those with mainly sand rootzones are.