Chapter 3 Clipping volume, or clipping weight?

The standard for measuring how much a turf sward is growing is to take the dry weight of the clippings mown off the turf.3 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 (Kreuser et al. 2011)? 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.4

An Acer palmatum in spring and a korai putting green in Fukuoka

An Acer palmatum in spring and a 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 the 1st green at Keya GC

sand topdressing application to the 1st 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?

Ratio of clipping fresh weight to volume and the change after sand topdressing application

Ratio of clipping fresh weight to volume and the change after sand topdressing application

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.

References

Kreuser, William C., Matthew P. Fish, Douglas J. Soldat, and Sam Bauer. 2011. “Removing Sand from Putting Green Clipping Samples Substantially Reduces Clipping Weight Measurement Error.” Crop Science 51: 1268–73. https://doi.org/10.2135/cropsci2010.10.0592.

  1. I wrote this blog post in July 2017 (http://www.asianturfgrass.com/2017-07-04-volume-or-weight/).↩

  2. Jared Nemitz and Adam Moeller have shared information in articles and videos about regular measurement of fresh weight. This video, “How It’s Done: Measuring Clipping Yield From Putting Greens” (https://youtu.be/QtgwEqYmV6A), and the “Improving Management by Collecting Data” case study (http://archive.lib.msu.edu/tic/usgamisc/cs/275023.pdf) describe how fresh clipping weight is measured from the 10th green at the Peninsula Club at each mowing, and explain how that information is put to use (Anonymous 2016).↩