Originally Posted by Skipster
Sand topdressing and sand-based rootzones are used for a very specific purpose. The USGA Recommendations for a Method of Putting Green Construction do not call for straight sand -- they call for a rootzone mixture meeting a specific set of particle size distributions and specific physical properties. Among those physical properties is that rootzone mixtures be 1 to 5% organic matter by weight.
Topdressing with straight sand is common because sand serves to dilute organic matter in the upper portion of the rootzone, in order to reach that 1 to 5% goal.
If you're managing athletic fields, construction and maintenance standards are available from ASTM (American Society for Testing Materials) and STMA (Sports Turf Managers Association). Those are different from USGA (US Golf Association) recommendations because they serve different purposes.
Trying to manage lawns the same way putting greens are managed is going to require putting green budgets and efforts.
Yes, thank you. I understand and agree. Typically my topdressing mix is testing out at 3-4% OM. Occasionally it contains a greater percentage of samd particle sizes on adjacent screens than what is ideal. For athletic fields it is fine and practical. Being able to provide the same mix from one year to the next has value.
Timing of sand topdressing on greens (primarily) is important, as I am sure you know. In terms of combating thatch and matching or offsetting the rate at which one's turf is producing it, as well as choosing a frequency and rate so that once diluted, OM remains in that 1-5 range requires a good eye, some good guesses, and good record keeping.
I built a good size green in my yard to USGA specs (very, very close) and maintained it for 17 years just to see if I could. Caring for it required an awful lot of time and materials - and water. Looking back at it now, I am sure it would have been easier to maintain had I used less sand. Then again, I did not need it to support 50,000 rounds a year lol.