Here's what gets me about the rock powders, and I'll use Azomite as an example -- 89% of what you get with Azomite is silica, alumina, with calcium, magnesium and sodium in whatever salt forms they exist within the aluminosilicate that it is. The amount of other nutrients and "trace elements" in the mix is quite small, and as illustrated in another thread when they are applied as directed the dilution effect means even if they were readily available the amounts you are actually adding are likely to be very small relative to naturally occurring background levels. With more silicate rocks the availability will be further reduced. So unless someone can demonstrate a real, measurable effect from a well controlled study, spending money of rock powders as a means to "mineralize" soils seems to me to be a waste as well as most probably ineffective. All of that is before we consider all the things that can come along with some of the rocks deposits that we don't really want to reinforce in ag soils, and that are often in greater abundance in those rock powders/dusts than the ones we know to be beneficial. The good news is that for the same reasons that they don't make sense to me as meaningful ways to add micronutrients and trace elements, they probably aren't a threat either.

Hi Sharon: You benefit me & others with your intelligent questions, which enable me to see what I did wrong with my past experiments. How did I cause rust by throwing POWDER GYPSUM on top? I repost the info: There's a U. of Nebraska research on rust, with the title, "Medium pH and Leaf Nutrient Concentration Influence Rust Pustule diameter on leaves of dry beans." Their conclusion: Plants grown in pH 5.8 medium show significantly larger rust pustules than plants grown in pH 6.5 or pH 7.9. Concentrations of Cl (chloride) and Mn (manganese) were more in high rust. In contrast, concentration of K (potassium) were less in high rust." From Straw: Alabama Agriculture Cotton Research also recommended potassium fertilizer to reduce rust. Info. about gypsum from USAgypsum.com: Elemental Calcium......21.0% Elemental Sulfur (S)....17.0% pH...................................6.8 Kelp4Less sells 5 lbs. of GRANULAR GYPSUM at 18% sulfur for $12.50 .... more than my local feed store, or Menards at $4.49 for 25 lb. bag. There's a quarry nearby that manufactures gypsum, so cheap here in my Chicagoland. I WOULD NOT use Pennington gypsum plus lawn fertilizer, if it's chemical nitrogen (high in salt). What I did wrong was to throw 1 cup of POWDER-gypsum on top ... it's acidic, plus fast release of calcium, which drove down potassium, necessary for rust-prevention. Previous times with 1/8 cup of GRANULAR gypsum, along with sulfate of potash ... no problems whatsoever. I would use even less GRANULAR gypsum, like 1 teaspoon, along with 1 teaspoon sulfate of potash, plus 0.2 cup of Milorganite. The best ratio for veggies is 1 part nitrogen, 1 part potassium, and 1/2 part calcium. Roses have a higher need for calcium, so I use equal amount to potassium. Sulfate of potash NPK is 0-0-50, and Milorganite NPK is 5-2-0. Take 50 divide by 5, you'll get 10. Ten teaspoons of Milorganite is equivalent to 0.2 cup, best with 1 teas. of sulfate of potash, and 1 teas. of gypsum. I would use more sulfate of potash & gypsum with pale own-root like Jude which needs more potassium for blooming, plus more sulfur for leaves to be darker-green. PALE own-root like Duchess de Rohan, W.S. 2000, Jude, Eglantyne, Honey Bouquet, Comte de Chambord can take more gypsum at 17% sulfur, and more sulfate of potash at 23% sulfur. DARK green roses grafted on Dr. Huey, and French roses dislike acidic sulfates. Bone meal has high sulfate at 2000 ppm, and 400 iron & 300 sodium, with the dark-green roses break out in diseases. I put too much bone meal in Gruss an Teplitz hole ... he's the parent of Dr. Huey, it became a BS-fest, and I had to fix the hole. Pennington fish pellets NPK 4-6-6, high phosphorus with fish bone meal. The pale & lighter-green roses LOVE that tea, today tiny Jude broke out in 2nd flush, 3 more buds with that tea, very fast repeat. Austin roses, bred in an acidic & high rain England like that ratio ... The ratio in David Austin Rose food has NPK 9.5 - 7.5 -10 ... a bit higher nitrogen due to high-rain England, which leaches out nitrogen. Acidic sulfates help pale-own-root to bloom better, but sulfates also burns if in direct-contact with roots, best as SOLUBLE. Pennington pellets is best as SOLUBLE tea under hot sun, to spoon-feed wimpy own-roots which can't acid-phosphatase as band-size. Bone meal is OK for pale own-root the planting hole, if mixed-thoroughly and buffered by plenty of soil. Bone meal burns if applied on top. Concentrated amount of sulfates near the stem burn. One person killed his tomato plant by topping with Jobe's Organic tomato fertilizer NPK 2-7-4, high in bone meal. When I mixed that stuff THOROUGHLY in the planting hole, I got bumper-crop tomato. Same with gypsum, at 17% sulfur, and sulfate of potash, at 23% sulfur. Both burns my finger, and burns any root, best used as soluble. If I sprinkle some on top, I flood the basin immediately with water, to dilute that, along with milorganite for nitrogen. Tomato Tone has NPK 3-4-6, neutral pH & less phosphorus ... it didn't burn my tomato plant, so that can be applied at 1/4 cup before a rain. It's finer particle & tend to float, best to let rain work that in. Milorganite is best 0.2 cup with 1 teas. sulfate of potash and 1 teas. of granular gypsum .... spread that on top before a rain, if you are lazy like me. Safe approach would be Milorganite on top, then make soluble out of potassium & calcium per gallon of water. Roses are all different from each other, the pale ones require more sulfates, potassium, and phosphorus via SOLUBLE to bloom. The darker-green leaves like Dr. Huey can secret acids to utilize nutrients from soil, thus breaking out in diseases when too much acid is supplied, like rain-water (pH 5.6 in East coast), or sulfates in bone meal, gypsum, and sulfate of potash .. which are components of Pennington Pellets. Sharon, best wishes with your roses. They all are different from each other ... such as pale Graham Thomas which required an ungodly amount of potassium & phosphorus as soluble to bloom for a Texan. It took me 3 years, and countless failed experiments to learn the above. This post was edited by Strawberryhill on Sun, Jul 20, 14 at 11:19

Peppers I'm growing are Cayenne, Jalapeno, Anaheim, Hungarian Wax, and Padron. They are in the ground and about 6 months old (though I think temperature here tends to slow growth) I've got about 10 plants in a row��"the only thing left in my garden as we move into dry season. All of them are exhibiting these symptoms to one degree or another. I have no idea what's in the fertilizer. It came in an unmarked bag and is composed of white pellets that I was told to apply and water into the soil. I was told it is a general-purpose vegetable fertilizer. Bought it from an agro-input store in town. If a nutrient deficiency is suspected, I may be able to get a more specific fertilizer, just requires a longer trip down to Kampala. Can also probably get epsom salt there.

The pictures are really too small to see enough detail. It's possible you could have several issues at one time occurring.