Clipping volume, or clipping weight?

I prefer volume for routine measurement because it reduces problems with sand contamination

The standard for measuring how much a turf sward is growing is to take the dry weight of the clippings mown off the turf. This isn’t a realistic option for routine turf management because who has drying ovens? And who can take the time to separate sand from clippings to reduce measurement error? I find it easiest to measure the volume of the clippings. That’s a fast and easy way to measure the clippings. I don’t like fresh weight as much as volume, because fresh weight requires a scale, has the same problems with sand contamination, and some variation based on water in the samples that I suspect is higher with weight than with volume.

Acer palmatum and korai putting green in Fukuoka

I was at Keya GC in Fukuoka in late May. On three of the greens at Keya, the volume and the fresh weight of the clippings are measured. I don’t recommend this! The only reason the maintenance staff are collecting these data are at my request, as part of a research project.

On May 29, sand topdressing was applied to the greens.

sand topdressing application to 1 green at Keya GC

So what happened after that topdressing? Mowing was skipped for a few days. When mowing resumed, see how the ratio of fresh weight to volume spiked? And then took over a week to get back down to what it was prior to topdressing?

chart of ratio fresh weight to volume

That’s the effect of sand contamination in the samples, and it is one of the reasons I prefer routine tracking of clipping volume to the tracking of clipping mass.