Jon,
I knew a European would respond to my comments in a negative way because it seems like Im endorsing the USGA or USGA spec greens or even American greenkeeping altogether. Im not endorsing anything other than sound agronomics. Whether its on this side of the pond or yours.
Like I said to Mr. Doak, sand is sand and soil is soil. It doesnt matter if its in the states or in Europe. Europe doesnt have "special" sand that they grow turf on. And the USGA doesnt have a "special" mix of sand and peat.
You have to take the sand and soil for what it is and analyze their physical attributes.
Jon if you gave me a green that was straight sand and the water percolated through the profile at 3 feet an hour, that green would be performing unacceptably.
If you gave me a brand new pushup green made of soil and no sand the water would percolate at 1inch per hour, that green would also be performing unacceptably.
Do you see where Im going here? Its all about balancing the two extremes. Moving the plant unavailable water and retaining the plant avilable water.
Back to a green that is straight sand. That comes with many problems. Straight sand has little to no ability to hold on to nutrients because of its electrical charges and sand seive analysis. Because of that fertilizing and watering is needed more frequently. Because of that I personally would modify that root zone with organic material and humic acids. The organic material would slow down the percolation rate of the water and the humic acid would create more cation exchange sites on the sand molecules to grab and hold onto nutrients.
Back to the brand new pushup green made of soil with little sand. Yes Jon, you are absolutely correct in that the soil green is rich in nutrients and requires less fertilization. And thats because its just the oppesite as the sand green. The soil has the great ability to grab and hold onto nutrients because of the amount of cation exchange sites on each soil molecule. But that green is also going to move water very slowly through the profile and it will only get worse because the soil will compact much more than the sand will. The other problem is that the soil will also retain alot of the water in the profile for a longer time, keeping it wet.
A wet green that moves water very slowly is a disaster waiting to happen. Especially if the green is in a hot a humid enviornment. Then it becomes an incubator for disease pathogens. While the green stays wet, the water molecules are filling up the macropores which are supposed to used as the ventilation tubes for the green. And the water in the macropores is also not even able to be taken up by the roots, its useless water. Clogging the ventilation doesnt allow oxygen in and it doesnt allow CO2 out. Then you have anaroebic conditions which lead to blacklayer which leads to poor turf quality.
In the case of a soil green thats drains poorly which causes that trainwreck what do you think should happen? Ammend the profile with sand!
Forget about anybodys damn "specs". Lets finally think about how nutrients and water react physiologically to different soils.
...."I would take issue with your last statement 'If a club doesnt already have USGA spec greens, the super is constantly striving to modify his pushup to achieve what a USGA green can already do. Move water' as it gives the impression that with USGA specs the super can sit on his ass enjoying a care free life."....
That statement is so far from the truth. My whole point was that if a super has old pushup greens that drain slowly, his whole M.O. is to perform the needed cultural practices to get that water to move through the profile quicker. The super that has the USGA spec green already has that. And because he already has that by no means he can sit on his ass. That statement is so offbase.
..."It is however IMO questionable to produce conditions for growing grass that make it difficult if not impossible to maintain any sort of cover without artificial watering or the use of P containing fertilisers for fine turf grasses.
Bad pushups can be a nightmare as you say but if done rightly they are far superior to USGA in that they require less fertilisers, are far more desease resitant and produce just as good a putting surface that is similar to the surroundings."...
...Im going to have to disagree again Jon. Lets start with disease. I would have to challenge you to produce an accredited study that has concluded scientifically that a pushup green is far more disease resistent. Thats such a broad statement, broad statements should never be made in this business. mainly because what works in one area of the world doesnt work in another. Every scenario has to adapt to its enviornment. Disease pressure come down to the three points. The host, the pathogen and the enviornment. That makes pushup greens just as susceptible as a USGA spec green. Again, I would love to see some data on that.
And could use please explain to me how a bad pushup green could have been done better. I would think a pushup green is what it is. If the soil in the area seems suitable for a green, then the soil is pushed up and shaped. If you are trying to tell me that at the time of construction the soil is modified with sand OR that the super with a pushup is aerifying and topdressing regularly to incorporate sand into the profile. Then Jon you are proving my point. The super with a pushup that drains slow is always striving to achieve what the super with a USGA green already has.
Pushups require less fertilizers because as I said the soil has the ability to retain nutrients. But that doesnt mean that the nutrients in the soil are available to the plants. Nutrients get bound up in the soil and only build up over time. Unless the super is aware of this and is doing the necessary practices to make sure that the nutrients get solubilized and plant available, then you have a completely inefficient use of fertilizers.
Stateside or in Europe. Its innefficient because there are tons of nutrients in the soil reserves that can be used if solubilized. Its free fertilizer! But most supers would just fert the greens on their regular schedule without paying attention to this. If a super does not know what a saturated paste extract soil test is then he has no idea of what his soil already has that is plant available.
In support of USGA greens. They are far more superior in nutrient efficiency. It has been proven over and over again that spoon feeding a green with chelated liquids is the most efficient way to fertilize. And with the rising cost cost of fertilizer its imperative to be efficient. Its imperative to know exactly whats already available to the plant in the soil and then to supplement that with small spoon fed / frequent applications of fert. And for your information Jon I dont put any phosphurus on my greens. Its already naturally there in the soil.
Artificial watering? If by that you mean syringing and misting the greens everyday then there again Ill throw the efficiency card out there. You spoon feed water just like you do fert. The plant only needs so much in certain spots at certain times. And that has alot to do with areas of the world. Southern California rarely sees "natural" water.
My girlfriends getting pissed at me blogging so Ill end it with that!
P.S. If I was told I had to choose between managing a USGA spec green or a soil pushup, but the stipulation was that Somebody else were to
choose where in the world I had to do it.....I would choose the USGA spec every time. The mere fact that I know it drains appropriately
and is efficient with nutrients makes it adaptable to any enviornment or situation.
But no, I dont think that USGA spec is the be all end all of green construction, however a well draining one is.