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.

Soil organic matter and N mineralization

I’ve been making estimates of N mineralization from soil organic matter for the past few years using the method described by Gilmour and Mauromoustakos in Nitrogen mineralization from soil organic matter: a sequential model.

Adding potassium fertilizer does not increase the soil's ability to store it

You’ve probably listened to one of my seminars in which I explained why conventional nutrient guidelines for turfgrass are broken. Jackie Guevara’s thesis on “Effects of Different Soil Testing Philosophies on Creeping Bentgrass and Annual Bluegrass Putting Greens” is an excellent demonstration of this.

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.