Tissue testing: aiming at the wrong target

This question arrived by e-mail:

“I have a couple questions –

A colleague and I in this area have been reducing N usage and tracking clipping yields for almost 2 years. He is utilizing tissue testing on a weekly basis, I send in a sample every couple weeks to see what is happening with nutrients, since our programs have changed with fertilization.

Is there any value in tissue testing?”

I wrote right back:

“I don’t like making nutrient application decisions based on tissue testing.

I would not do routine tissue testing if I were a golf course superintendent.

I like tissue testing for research purposes and spend plenty of my own money on tissue tests, but for a lot of reasons I don’t think it is an optimal way to make management decisions.”

My correspondent replied with a couple more questions:

“Thanks for the reply – do you not like it because of variability? Timing, nutrient, uptake etc….”

And I gave this brief elaboration.

“I will respond sometime later on my blog with more detailed explanation.

In short, I don’t like it because turf management is about producing surfaces, not about manipulating leaf nutrient content. It doesn’t make sense to me to try to manipulate leaf nutrient content when excellent turf surfaces can be produced with a wide range of leaf nutrient levels.

Applying nutrients based on tissue nutrient content is kind of like trying to hit a moving target with the thought in the back of your mind that the target may not even be the one you really should be aiming for.”

The more detailed explanation is forthcoming.