A Simple Test with Big Implications for Soil Health, Fertility, and Structure
Know What Your Soil is Made Of—Literally
Organic matter is one of the most critical components of healthy soil. It affects everything from nutrient retention
and water-holding capacity
to microbial activity
and soil structure. The % Total Organic Matter by Loss on Ignition (LOI)
test provides a straightforward but powerful measurement: how much of your soil is made up of carbon-based, organic material.
This test is used by farmers, soil consultants, composters, landscapers, and researchers
to benchmark soil health, compare material inputs, or track improvement over time.
What This Test Tells You
Using the Loss on Ignition (LOI)
method, we determine the percentage of your soil that is made up of organic matter
—plant residues, decomposed biomass, humus, and living organisms.
Organic matter influences:
Water retention
– Especially important in sandy or drought-prone soils
Soil structure
– Helps build tilth, porosity, and resistance to compaction
Microbial activity
– The higher the organic matter, the more fuel for life
Cation exchange capacity (CEC)
– Directly correlated with organic content
Whether you’re rebuilding depleted soils, evaluating compost amendments, or optimizing root zone conditions, this test offers an essential data point.
Why Choose This Standalone LOI Test?
✔️ Quick and cost-effective ✔️ Trusted method for total organic matter estimation ✔️ Ideal for comparing compost, topsoil, media blends, or degraded vs. improved sites
Regenerative farmers
tracking soil health progress
Compost producers and buyers
evaluating organic inputs
Landscape professionals
sourcing or verifying topsoil and blends
Golf course and sports turf managers
maintaining performance turf
Researchers and students
analyzing soil composition and variability
Sample Requirements & Turnaround
Sample Size: 3–4 cups
Turnaround Time: 3–4 business days from lab receipt
Report Format: Percent Total Organic Matter (% TOM) via LOI method
Note: This is a data-only
test. No interpretations or fertilizer recommendations are included.
Order the % Total Organic Matter by LOI Test Today
Don’t overlook one of the most powerful indicators of soil health. This simple test gives you the foundational data to improve fertility, sustainability, and productivity.
Hi there! Have some questions about our company? Find the answers below.
What are your business hours?
Our office is open Monday thru Friday from 8 am to 5 pm. We do close for major holidays, so we recommend ordering your testing and sending your sample early if a holiday is coming up. You can always reach us by email. Just send us a message at info@tpslab.com
When will I get my results?
We understand that you need your results as soon as possible. That is why we make sure to begin processing your samples as soon as they arrive at our laboratory. When the results are ready, we will email them to the email address you provided on your submittal form. The list below will give you an idea of our usual turnaround times.
Soil Tests: 5-7 Business days
Water Tests: 5 - 7 Business days
Plants Tests: 24 - 48 Hours
Compost Tests: 7 - 14 Business days
Fertilizer Tests: 3 - 5 Business days
Heavy Metals Test: 7 - 14 Business days
We offer a rush option for an additional 50% of the testing cost, but we would encourage you to give yourself time to test before you get to a point where a rush is needed.
