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.

OM246 sampling instructions

I’ve written a lot about OM246 testing for total organic material by depth in the soil, and why I think this test is so useful. Something I hadn’t written, until this week, is my own set of sampling instructions.

Simple solutions to a difficult problem

When Bernd Leinauer introduced me prior to this talk, he mentioned that I’m one of the most controversial turfgrass scientists today. And the reason for being controversial happens to be the very topic of this presentation1 that I’ve uploaded today to my YouTube channel.

MLSN and turfgrass nutrient recommendations

GCM Magazine has another article about the SLAN and MLSN methods for soil test interpretation. The article summarizes Jackie Guevara’s research (with Kevin Frank at Michigan State University) into turfgrass response when P and K applications are made based on MLSN.

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.