C
CascadeFarmer
There was thread elsewhere at IC that got binned because of fighting but one subject covered caught my attention. A few years back I played with the idea of foliar applications of micronized calcium carbonate mainly for treatment of Powdery Mildew but also wondered about CO2 liberation. Heard a story where a squash farmer, cucurbits seem very prone, successfully treated his crop with foliar CaCO3. I was told by the consultant who dealt with the guy that the particles needed to be less than 5 microns to ensure entry into the stomata. I thought the stomata might just get plugged up so found material from Reverte that was 1 micron.
In looking at the chart of particle size you can see there's a decent amount of particles over the Statistic Mean Diameter. I could not find the chart for the 1 micron samples I received but you get the idea (see chart below).
In looking at things more I came across Nano Precipitated Calcium Carbonate from Specialty Minerals. They start with lime and end up bubbling CO2 through the solution to 'synthesize' CaCO3. The sample I got was .06 microns or 60 nanometers and the particle size does not vary much with NPCC. I thought the smaller the better.
Then I saw CalCarb from Xtreme Gardening and they claim...
Here they talk about rapid conversion and don't know if this is happening on the leaf surface, don't see how, or if it's going on once it enters the stomata.
A bit more about vaterite...
In looking at the chart of particle size you can see there's a decent amount of particles over the Statistic Mean Diameter. I could not find the chart for the 1 micron samples I received but you get the idea (see chart below).
In looking at things more I came across Nano Precipitated Calcium Carbonate from Specialty Minerals. They start with lime and end up bubbling CO2 through the solution to 'synthesize' CaCO3. The sample I got was .06 microns or 60 nanometers and the particle size does not vary much with NPCC. I thought the smaller the better.
Then I saw CalCarb from Xtreme Gardening and they claim...
They talk about 'a new form of nanotechnology' and wondering if they are simply using NPCC which actually has been around for decades. They go into the CO2 thing.Calcium Carbonate Foliar Spray is Xtreme Gardening’s revolutionary calcium carbonate foliar spray which increases CO2 levels from 0.03 vol% (atmospheric level) to 0.1 vol% – the optimal level desired by plants. CalCarb utilizes a new form of nanotechnology which allows for topical application, which is applied just twice a month. Often, viewed initially with skepticism and deemed the most unbelievable” of all the products in the Xtreme Gardening Line, CalCarb delivers what no other product can – natural, time-released CO2,without the use of tanks and propane/natural gas burners.
Here they talk about rapid conversion and don't know if this is happening on the leaf surface, don't see how, or if it's going on once it enters the stomata.
They talk about an unstable form of CaCO3 and wondering if it's because of the particle size, Specialty does make material up to 150 nanometers, or if it's really a different form. I kind of doubt that but...CALCARB is a unique form of a simple and very common compound that contains both calcium and carbon. Calcium carbonate is used in agriculture throughout most of the world to adjust soil pH levels. CALCARB is an unusual form of calcium carbonate that is highly unstable, converting to calcium oxide and carbon dioxide rapidly when applied to foliage.
When they talk about nano stuff only thing I'm familiar with is the NPCC material. Maybe it's the particle size that makes NPCC, if indeed that's what Xtreme is using, effective?PCC stands for Precipitated Calcium Carbonate—also known as purified, refined or synthetic calcium carbonate. It has the same chemical formula as other types of calcium carbonate, such as limestone, marble and chalk: CaCO3. The calcium, carbon and oxygen atoms can arrange themselves in three different ways, to form three different calcium carbonate minerals. The most common arrangement for both precipitated and ground calcium carbonates is the hexagonal form known as calcite. A number of different calcite crystal forms are possible: scalenohedral, rhombohedral and prismatic. Less common is aragonite, which has a discrete or clustered needle orthorhombic crystal structure. Rare and generally unstable is the vaterite calcium carbonate mineral.
A bit more about vaterite...
Vaterite (CaCO3) is a mineral, a polymorph of calcium carbonate. It was named after the German mineralogist Heinrich Vater. It is also known as mu-calcium carbonate (μ-CaCO3) and has a JCPDS number of 13-192. Vaterite, like aragonite, is a metastable phase of calcium carbonate at ambient conditions at the surface of the earth. As it is less stable than either calcite or aragonite, vaterite has a higher solubility than either of these phases. Therefore, once vaterite is exposed to water, it converts to calcite (at low temperature) or aragonite (at high temperature: ~60°C). However, vaterite does occur naturally in mineral springs, organic tissue, gallstones, and urinary calculi. In those circumstances, some impurities (metal ions or organic matter) may stabilize the vaterite and prevent its transformation into calcite or aragonite. Vaterite is usually colorless, its shape is spherical, and its diameter is small, ranging from 0.05 to 5 μm. Vaterite can be produced as the first mineral deposits repairing natural or experimentally induced shell damage in some aragonite-shelled molluscs (e.g., gastropods). Subsequent shell deposition occurs as aragonite.