Agriculture
Aragonite, an OMRI Listed calcium carbonate for organic growers
Two of our grades are OMRI Listed for organic crop production, sized for your soil and delivered to specification. We're the world's largest supplier of oolitic aragonite, a pure, renewable calcium carbonate (CaCO₃) harvested from the shallow waters of the Bahamas. We have never had a rejected load.
Organic production
OMRI Listed for organic crop production
The grades we supply for organic crop production, DF Aragonite (dried and screened) and SP Aragonite, are OMRI Listed: reviewed by the Organic Materials Review Institute and listed as Allowed under the Crop Fertilizers and Soil Amendments use class, with no restrictions attached. The listing is held under our operating company, Ag Source, LLC of Mifflintown, Pennsylvania (the name that appears on your invoice), so your certifier can match the paperwork to the listing without having to call anyone. Custom grades milled outside those two products are not covered by the listing; if you need a bespoke gradation for certified ground, tell us and we'll tell you where it stands.
If you're sourcing bulk agricultural lime for organic ground, you're shopping the same aisle: a bulk calcium carbonate (CaCO₃) soil amendment. Ours is oolitic aragonite, grown in seawater rather than quarried and crushed, OMRI Listed, and available by the truckload or the railcar. We publish a typical analysis and not a neutralizing value, so qualify the material against your soil program the way you would any other input.
| Listed product | OMRI ID | Status |
|---|---|---|
| DF Aragonite – dried and screened | asu-4914 | Allowed |
| SP Aragonite | asu-4915 | Allowed |
Listing status is maintained by OMRI and not by us. Confirm it directly at the link below before you certify a load.
PCO Certified Organic
Ag Source, LLC (our sister company) is certified organic by Pennsylvania Certified Organic (PCO) to the USDA organic regulations (7 CFR Part 205) for Handling.
Certification status is maintained by PCO and the USDA, not by us. Look up NOP ID 8210001017 in the Organic Integrity Database to confirm it before you certify a load.
In the ground
What bulk aragonite does for organic ground
Reliable, uniform chemistry
Bahamian oolitic aragonite is a very pure calcium carbonate with uniform chemistry, load after load. Limestone varies wildly inside a single deposit. Aragonite hands you the same analysis every time, so your program holds season to season.
Effective calcium delivery
Aragonite is a more effective vehicle for calcium delivery in the substrate and the foliage. Quicker breakdown of nutrients means healthier plants, larger plants, and better-tasting produce.
A renewable resource
Limestone is finite and quarried. Aragonite forms continuously in the shallow Bahamian banks where the Atlantic meets the Gulf Stream. It is a renewable calcium source.
Sized to your operation
We run coarse through ultra-fine, depending on the crop and the operation, with tighter gradations on request where a standard size isn't close enough.
Before you spec it. What is oolitic aragonite
Specifications
96% CaCO₃ minimum, on the typical analysis
The values below are the typical analysis of our oolitic aragonite as harvested and processed, published so you can qualify it against your soil program before you buy.
Growers work from CaCO₃ at 96% minimum for calcium and purity, MgO at 0.35%, and the sieve analysis, which is the gradation you'll actually be applying. The low Fe₂O₃ maximum of 80 ppm is a read on the purity of the whole material.
| Analyte | Typical value |
|---|---|
| Fe₂O₃ | 80 ppm max |
| CaCO₃ | 96% min |
| MgO | 0.35% |
| H₂O | <1% |
| US mesh | % retained |
|---|---|
| +20 | 0 |
| +30 | 28.7 |
| +40 | 28.5 |
| +50 | 25 |
| +70 | 12.7 |
| +100 | 4.1 |
| +140 | 0.8 |
| +200 | 0.2 |
Typical values, not a guaranteed analysis. Certified assays available on request.
Supply and delivery
Bulk soil amendment, at the volumes ground work takes
Marcona's former principals run Aragonite Source, and they harvested aragonite at Ocean Cay from the 1970s into the early 2000s. That's more than 50 years on the water and millions of tons sold.
We dig in close conjunction with the Bahamian government, at sites chosen for uniform test results and for renewal. Material is sized to the right gradation at our own facility.
From there it ships on our own truck fleet, plus rail out of our own yard. Consistent, and on time. No load has ever been rejected, and we have never failed to meet customer demand.
Send us your spec.
Tell us the gradation your spreader needs and the tonnage, and we'll get you aragonite that hits it, every time. The Industry field below is already set to Agriculture.
Thank you. We're on it.
Your inquiry is in. We'll be in touch shortly. The email and phone above stay open if you'd rather not wait.