nitrogen

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.

There’s an interesting article by Espevig et al. on Effects of rolling and N-fertilization on dollar spot and Microdochium patch on golf greens in Scandinavia. rolling a red fescue green two times a week reduced dollar spot by 61% compared to no rolling rolling four times a week reduced dollar spot by 95% increasing annual N on a creeping bentgrass + Poa annua green from 15 to 24 g/m2 reduced dollar spot by 24% but the following spring saw twice as much Microdochium patch on the plots which received the higher N rate There are a number of surface performance benefits that come from rolling, and disease suppression is one of them.

The other day it rained at ATC南店. I knew that the grasses would grow at a faster rate after the rain than they had been growing prior to the rain.

I put the series of genki level (GL) blog posts together into this 17 page pamphlet. The pamphlet explains how one can calculate the genki level from the actual N supplied as fertilizer compared to a standard amount of N for any time duration.

The turfgrass genki level is a way to express the degree to which turgrass is being pushed to grow, or restructed from growing, by the supply of nitrogen.