This is interesting, and frustrating!, info -- thank you. After much deliberation, we decided to apply AgSil to our apple trees this season, starting at budswell/greentip with a soil application intended to build up a reservoir for the trees, continuing with at least two foliar applications during bud/bloom, and then see where we stand via plant sap analysis. For us, while AgSil contains far more potassium than we'd like to be applying regularly (0-0-32), particularly as we wade deeper into the calcium paradigm now that we know that potassium levels can play an ultimate role in calcium availability, we are equally leery of applying very alkaline silicon-containing products that may raise the soil pH, like CropSIL. Perhaps one would have to alternate products like these two with each other, so you don't get to the point of having to cut either one because of the incidental "side" effects of adding silicon in this more conventional (as opposed to fermented teas) manner.
At any rate, reading the information you provided made me feel better about applying at least our first silicon appliation to the soil rather than the foliage. We're now at silvertip, and since AgSil is slated to be the next thing we spray in the orchard, I spent the morning working out how we might apply it to the ground using our airblast sprayer. I feel pretty good about the calibration, spread, and overall coverage, but my mother had an interesting observation as we discussed timing and methods: so being that we have such a healthy orchard floor, and being that our grasses, etc. are no longer dormant either, we are going to essentially be applying AgSil as a foliar spray to our orchard floor . . . and where does that leave the trees? Even if we had applied it to the soil, say, 3 weeks ago, when grasses, etc. were still more or less dormant, that silicon reservoir we're fostering in the our orchard soil is presumably going to be supporting a lot of orchard floor before the trees get to take their cut.
Of course, it's all about the orchard as an overall environment, but just one more thing to make us feel like, to large extent, we may be throwing a lot of money at a problem ($250/fifty lb bag, to be exact), and may not see the effect we're going for. At least with the foliar apps, you're applying it mostly to the trees themselves.
Tangentially related, we're also curious about grinding up bamboo and mulching with it as a long term silicon source . . . maybe next year.
Kordick Family Farm
Westfield, NC
Zone 7a
Edited 1 time(s). Last edit at 03/12/2021 10:15PM by Brittany Kordick.