7 Questions to Ask Before You Buy Any Soil Amendment
Most soil amendment sales calls are won on adjectives. "Premium." "Biologically active." "Just like nature." None of those words have ever been lab-tested.
Here are seven questions that turn the conversation from adjectives into numbers. Ask them of every vendor, us included. We've answered all seven for our own products below, because if we're going to hand you the questions, we'd better be able to pass the test.
1. What's the C:N ratio, and who tested it?
Why it matters: C:N ratio shows how decomposed a material is. A high ratio means it's still breaking down, and it's borrowing nitrogen from your turf to finish the job. (We break down the mechanism in our C:N ratio post.)
A real answer: A specific number, a named independent lab, and a report you can actually see.
A red flag: "Highly mature" with no number attached. A number that only appears in the company's own marketing sheet. An unusually low number with no lab behind it.
Our answer: Across lab analyses, DAKOTA Peat's C:N ratio has fallen in the 15:1–24:1 range. The most recent independent report (Control Labs, sample LR25-002, January 2025) came in at 15:1.
2. How decomposed is it, and how do you know?
Why it matters: There's a real difference between organic matter that has fully decomposed into stable humus and organic debris that is still decomposing. Most products get marketed as the first. Plenty are the second. (This is the Debris Cycle.)
A real answer: It explains where the material came from, how long it had to finish becoming what it is, and backs that up with a measurement.
A red flag: "Just like nature." A "finished" claim with no test behind it. A product formulated recently to imitate what time does naturally.
Our answer: DAKOTA's material comes from an ancient reed-sedge deposit formed over thousands of years. It wasn't manufactured to mimic a stable material. It spent millennia becoming one, and the C:N number is consistent with that.
3. Who ran the research, and what was it compared against?
Why it matters: The comparison group decides what a result means. Beating a weak comparator is easy. A study can be real data and still be narrow: small plots, short timelines, or preliminary results presented as final.
A real answer: A named university or researcher, a clear comparator, defined conditions, and ideally peer review.
A red flag: One study cited for everything. A comparator that's the weakest option available. "Interim results" that are never followed by a full dataset.
Our answer: Iowa State University tested DAKOTA Peat against pure sand and Profile (calcined clay) on creeping bentgrass under normal, low-nitrogen, and high-temperature stress conditions. North Dakota State University (Dr. Deying Li and Dr. Yang Gao, Department of Plant Science) conducted a peer-reviewed study on DAKOTA REV as a foliar tank additive on creeping bentgrass.
4. Can you show me the biology, not just an adjective?
Why it matters: "Biologically active" is a marketing phrase. Species counts and functional data are measurements. Ask for the method, the lab, and the report.
A real answer: A lab report with species-level or functional data, a named lab, and a date.
A red flag: Relative claims ("more diverse," "higher populations") with no baseline and no report to look at.
Our answer: Independent BECROP DNA sequencing by Biome Makers, January 2024: DAKOTA Peat, 811 species (Report #DI9000). DAKOTA REV, 650+ species (Report #DI9001). Published in full in our microbiome data post, including the numbers that don't flatter us.
5. Is it the same every time?
Why it matters: One good lab result on one batch isn't a specification. Consistency means multiple results over time.
A real answer: Several reports across batches, with the variation disclosed.
A red flag: A single "typical" analysis. Specs described as targets rather than measurements.
Our answer: DAKOTA's C:N has stayed within the 15:1–24:1 range across lab analyses. That's what you'd expect from a deposit that formed the same way over thousands of years, as opposed to a process run to hit a target on every batch.
6. Does it fix the cause, or add one more thing to the stack?
Why it matters: A lot of products are built to patch a single symptom. If your program needs a bottle for every symptom, ask what's causing the symptoms.
A real answer: A clear statement of what job it does and what you can stop buying.
A red flag: Another bottle for another symptom. "Works best alongside" a long list of other products.
Our answer: DAKOTA Peat adds stable organic matter and native biology to the rootzone. REV Turf Pro delivers that same material, with its humic acid, bioavailable carbon, and native microbiology, in a single tank pass. (More in why one tank pass.)
7. Can I talk to someone who has actually used it?
Why it matters: Field results beat brochures, and names attach accountability.
A real answer: Named superintendents, named courses, and specific numbers.
A red flag: Anonymous testimonials. "Results may vary" doing most of the talking.
Our answer: As reported by the superintendents themselves: Black Bear GC (Cloquet, MN) cut fertilizer spend from $78,000 to $25,000. Arrowhead GC (Littleton, CO) reported a 40% fertility reduction. Silos CC (Kevil, KY) reported a 20% water reduction and zero wetting agents. Full stories are in our superintendent results post.
Use These on Everyone
Any vendor worth buying from will be glad you asked. If the answers come back as adjectives, you've learned what you needed to know.
Quick Answers
What should I ask a soil amendment supplier?
Ask for the lab-tested C:N ratio and who ran the test, how decomposed the material is and how they know, who ran any supporting research and what it was compared against, the biology data behind any "biologically active" claim, batch-to-batch consistency, what the product replaces rather than adds to, and a named superintendent who has used it.
How do I know if an organic amendment is mature and stable?
Ask for the C:N ratio from an independent lab. Material that has fully decomposed settles into a stable range, while a high ratio indicates it is still breaking down and consuming nitrogen. An unusually low number with no named lab behind it deserves the same scrutiny.
How do I verify biological claims on a soil product?
Ask for a lab report showing species-level or functional data, the testing method, the lab's name, and the date. Relative claims with no baseline and no report aren't measurements.
Why does it matter who ran the research behind a product?
The comparator and the conditions decide what a result means. A named researcher, a clear comparison, and defined conditions let you judge it yourself.
More from the library: the ideal C:N ratio for topdressing, the Debris Cycle, the complete independent microbiome data, and real superintendent results.
