Estimating turfgrass nutrient use, Ontario 2015
Ontario Golf Superintendents Association, Niagara Falls
This is the handout for a presentation on this topic at the Ontario Golf Superintendents Association conference. It includes the presentation slides and links to additional information.
Slides
These are the presentation slides on slideshare. For a PDF version of the slides, download from Dropbox.
This is another attempt to explain nutrient use and requirements for turfgrass. To browse other presentations that looked at a similar topic, see 4 versions of the same topic.
Key Points
In the presentation, I explain how I go about answering the two important questions every turfgrass manager should have about fertilizer. First, is this element required as fertilizer, and second, how much of it should be applied? I show how these questions can be answered by estimating three quantities, which today I called a, b, and c.
- a is the quantity of an element used by the grass
- b is the quantity of an element that must be kept in the soil to ensure the grass will have access to enough of that element
- c is the quantity of an element that is actually present in the soil
It becomes apparent that a + b is the quantity that we need to have, and c is the amount that we actually do have. It follows that the amount of an element to apply as fertilizer is the result of a + b - c, if we can only get good estimates of a, b, and c.
The answers for b and c are easy; these correspond to the soil test interpretation guidelines that we work with – I recommend the MLSN guidelines – and the amount of an element measured by the soil test, respectively. It turns out to be straightforward to get a reasonable estimate of a also, by considering that the maximum quantity of nutrients harvested will be less than the quantity of N supplied. This approach is based on the growth potential model of PACE Turf.
Examples are shown for Toronto, Ottawa, and Vancouver.
Links to more information
- The MLSN guidelines.
- Climate appraisal forms from PACE Turf with the growth potential equation and lots of other necessary information already embedded in the downloadable spreadsheets.
- A detailed explanation of MLSN.
- The Global Soil Survey.
- MLSN on Facebook.
- Posts tagged Fertilizer on the Asian Turfgrass Center blog.
- I didn’t put a link to this explanation of growth potential in the slides, but it is a fuller explanation of this approach.
Notes
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Find reference information, site-specific weather and climate appraisals, and weekly updates at PACE Turf.
For more about ATC’s soil testing services, and example reports, see our soil tests page.
See more about OM246 testing, including sampling instructions and a sample report, at the OM246 project page.
For even more information, see: