Anyone have any input on this? If I can't find any proof, I guess I'll have to go down the road of doing my own study on it. I figured I'd hit up the community for some input first, though.

Thanks

The amount of small pourous areas and a high surface around would give bacteria a lot of place to set up, but to get enough bacteria to "die" to form enough nitrate for agriculture use you'd need an extremely huge amount of the stuff to get decent N...plus a very healthy bacteria population.

You'd probably need many 100s of pounds per acre of the stuff plus inoculate (or create favorable conditions) for bacterial growth while finding a way to incorporate the stuff without it effecting soil pH adversely.

The recommendation for aragonite is 250-750 pounds per acre. So, the suggestion that you'd need hundreds of pounds per acre is accurate (according to raw-aragonite.com).

Heavy nitrification reduces the pH of the soil. As the pH decreases the rate of nitrification also decreases. An additional benefit of aragonite is that it buffers the pH up, allowing nitrification to continue at high levels for extended periods.

The aragonite itself acts as a carbon source for the bacteria for nitrification. Additional organic matter isn't required as a food source for the bacteria.

The product is priced at $300/ton, which should handle between 2.5-8 acres. If this can be used as a replacement for nitrogen fertilizer, it could actually cost less. This is where I'm stuck. Can it replace nitrogen fertilizer or is it snake oil?

A few thoughts and questions to be considered:

250,000 bacteria per gram is very small. Most healthy soil has millions to billions of microbes per gram. So it does not seem like a microbial boost, at least in terms of total numbers.

If it's all about surface area, does it really add significant surface area for microbe growth? I forget how many tons of soil are in an acre-foot, but even a ton per acre of an amendment would, again, be a tiny addition to the total mass and therefore the total surface area.

If, instead, it's all about using carbonate while producing nitrate, why wouldn't any calcium carbonate work just as well?

Just some things that come to mind, not pretending to have all the answers to them.

The surface area of aragonite is huge. It's very porous. Aquarists use aragonite as a substrate and filter media specifically because of the porosity, which gives the bacteria enormous area to thrive. There just isn't anything better than aragonite for surface area in a small space. Does that translate to huge surface area for soil-dwellng bacteria? No idea.

I've searched extensively for research papers on aragonite as a soil amendment for free-living nitrifying bacteria and have come up empty.

Aragonite is a form of calcium carbonate, just as limestone and crushed shells. Limestone and crushed shells are calcite, which is a very hard form of calcium carbonate. Aragonite has a different crystal lattice that forms a weak bond, increasing the solubility. The increased solubility makes the calcium in aragonite more freely and easily available for plants. So, there are definite benefits for using aragonite as a calcium source as opposed to the other forms of calcium carbonate.

While typical soil contains enormous amounts of microbes, does that translate to enormous amounts of nitrifying microbes? I've read that typical soil will product less than 10 pounds per acre of nitrates per year, which is considered insignificant for crops. Thus, the need for nitrogen supplements.

Perhaps the solubility of aragonite that will increase the pH of the soil to allow for higher rates of nitrification in the soil bacteria themselves is part of the added benefit. More questions than answers.

Anyone know of a soil scientist or agronomist that might be able to do some analysis?

If I can't get answers, I plan to do a soil study both with and without plants to determine nitrification benefits of aragonite. I think it would be interesting to see whether soil nitrates will increase simply by adding aragonite, and then to be able to measure the exact amount. I will also perform the test with plants to determine if there's any growth improvement with using aragonite.

Whoppingly? 5 yard penalty and loss of down for makin up words. :-D

That said, you're talking about very small amount...almost negligible until you have a massive amount dieing off...which would be helped (in theory) by having all these surface areas in a mineral like this to hang out around.

That said, while the bacteria are still alive they consume N...so you get another negligible situation of self-feeding unless you get more dieing that living in the soil system.

The bacteria that fixates atmospheric N is a symbiotic relationship with a plant as much as it is the bacteria, itself. The plants that fixate atmospheric N can kinda be thought of as "sinks" for storage that are facilitated by the N-fixing bacteria. You need both for the noticeable effect. The plants can only fix/store so much of this, though...so you're better off focusing on the quality of the plant to fixate the N rather than increasing the amount of N-fixing bacteria once you already have a healthy population of N-fixing bacteria.

Aragonite would involve free-living bacteria by giving them increased surface area in which to live.

Until they "die" they're practically useless, yet more dieing would feed those that spawn unless you can manage your cycle of bacterial life to create then dump via death. That would be the hard part and probably require a future inoculation to get the population back up and running for the next cycle.

In the end, it's a very small amount of N addition for the amount of input...and in this kind of farming/harvesting method to get that N there would be concerns about pH in some soils given the easily weathered structure of the parent material heavy in CaCO3. It wouldn't be so bad in acidic soils, though it would do little to address one of the main problems with acidic soils, aluminum sequestration, compared to some other more complete (and less "pure") liming materials.