Soil test

Soil tests

We provide soil testing services for clients around the world through Brookside Labs, and have an active research program in the area of turfgrass nutrition, soil and plant analysis, and sampling methods.


Minimum levels for sustainable nutrition—MLSN—is a modern method for interpreting soil tests for turfgrass.

Global Soil Survey

A project that investigated soil nutrient levels of good-performing turf all over the world.


Measure exact topdressing effect, and requirement, by checking total organic matter by depth.

Extending the beer analogy

I’ve explained how MLSN works by telling a story about beer. Specifically, about a natural and logical method to figure out how many beers to buy at the store prior to an upcoming party.

Soil organic matter should be invigilated

A substantial amount of organic material accumulated at the surface of a Tifdwarf bermudagrass putting green at Rota in the Northern Mariana Islands. I don’t recall if I read this exact statement, or if it occurred to me when I read something else about invigilation.

A turfgrass Shiny app collection

I’ve made a number of Shiny apps, and have collected them all on this new page. These are designed either to show a set of data, or more likely, to make some calculations with the inputs allowed to vary.

Soil test showdown

A recent PACE Turf update mentioned this research project by Jackie Guevara and Kevin Frank: Effects of different soil testing interpretation philosophies on creeping bentgrass and annual bluegrass putting greens.

5 examples of Goodhart's law in turfgrass management

When a measure becomes a target, it ceases to be a good measure. That’s a generalization of Goodhart’s law. I’m an advocate of measuring some surface performance, plant, and soil parameters.

A Tale of Two Tests

This post takes a few minutes to read because it covers this topic in a bit of detail. The summary is, I make use of two types of soil organic matter tests for turfgrass, these tests measure two different things, both important, and I recommend turfgrass managers measure both of these, ideally once a year.