nitrogen

For a few years now, when I have private discussions about the type of putting green maintenance that involves few or no holes punched in the surface and minimal sand topdressing, I often hear this response.

After the 2014 GCSAA nutrient survey, I wrote a blog post titled “maybe those that soil test are just more likely to fertilize in general?” I made the case that although they might be more likely to fertilize, there seemed to be an effect of soil testing on that too, at least for K.

A pound of nitrogen. That’s a substantial amount of N, right? Apply a pound of N in a single application and that’s going to create a lot of growth—way too much growth in most cases—and may lead to some thatch production.

This topic—carbon in turfgrass soils—was the subject of a Frankly Speaking podcast episode. One of the topics host Frank Rossi spoke about with guests Drs. Claire Phillips and Alec Kowalewski was the nitrogen mineralized from soil organic matter.

Have you ever seen seedheads on zoysia? Have you ever planted zoysia sod and seen a lot of seeds on some pieces but not on others? I’ve seen this a lot, and I’m not the only one.

I’ve been thinking about this one a lot. It seems obvious that a sward supplied with more nitrogen fertilizer will tend to produce more organic material in the soil. It also seems obvious that a sward on which hollow-tine cultivation, or scarification, or sand topdressing, have been conducted, will need to receive more nitrogen in order to produce a surface compared with an adjacent sward that didn’t receive any of that work.

Doug Soldat joined me for an ATC Office Hours discussion about leaf nutrient analyses (tissue testing) for turfgrass. I’ve embedded the video at the end of this post, link to it here, or listen to the podcast version here.

I’ve been making estimates of N mineralization from soil organic matter for the past few years using the method described by Gilmour and Mauromoustakos in Nitrogen mineralization from soil organic matter: a sequential model.

Phil Collinson asked an interesting question: when calculating N inputs, do greenkeepers account for N added outside of fertilizer? Greenkeepers - when calculating N inputs for the year do you account for N outside of fert?

In the last ATC update newsletter I included a survey about future video topics. These are the results. Thanks to everyone for the feedback! A topic that has been on my mind and that I want to explain further is N fertilizer and ClipVol.