Soil organic matter and N mineralization

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.

N input accounting

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?

ATC newsletter survey results: future video topics

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.

Rolling, nitrogen, dollar spot, and Microdochium patch

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.

Post-rain growth flush from nitrogen in the rain or nitrogen from the soil

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.

Genki level pamphlet

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

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.

The turfgrass genki level, part 5: what's real, what's not, & the simplicity of this

In this series of posts, I’ve showed how one can start with temperatures and go all the way to a standardized comparison of growth in response to nitrogen supply. In this one, I want to emphasize which of these are real, which aren’t real but are useful, and to make an argument that this is a lot easier than it might seem.

The turfgrass genki level, part 4: a normalized comparison of N fertilizer to growth rate

The amount of nitrogen (N) supplied over a certain time duration, compared to a standard amount, is what I call the genki level (GL). And the amount of clippings harvested over a certain time duration, compared to a standard amount, is what Jason Haines calls the turfgrass speedo.

The turfgrass genki level, part 3: turf growth response measured by clippings

In part 2, I showed how the ratio of N applied to standard N gives an indication of how much one is pushing the grass to grow. I call that the genki level (GL).