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.


These are the presentation slides on slideshare. For a PDF version of the slides, download from Dropbox.

Estimating Turfgrass Nutrient Use from asianturfgrass

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.

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.