The nuance of soil amendments comes down to nutrient balance and availability, the cost, and whether you can get things near rather than far. Purchasing a mix of products from one supplier that can fit on a single pallet and then be shipped by freight carrier is smart. A web search can reveal useful information in distinguishing one product from another if you review several sites to get a composite view. I'll do this for the trace mineral amendment and leave rock phosphate and kelp for other posts.
AzomiteA to
Z of
Minerals
Including
Trace
Elements. This complex silica ore was formed when the inland sea, fed by hundreds of rivers rich in minerals, covered a volcanic ash deposit rich in rare and abundant minerals itself. This clay-like amendment mined in Utah has over 66 minerals and trace elements that are important for plant nutrition and growth. It improves depleted soils. Excellent anti-caking agent and offers a large spectrum of trace minerals allowing soils to effectively re-mineralize. See
Azomite Minerals.
Redmond ConditionerAncient salt deposit mined in Utah which contains over 50 mineral compounds in natural proportion and balance. These trace minerals are colloidal, which means they are in a condition ready for immediate utilization. Applied to soils and plants, and fed to livestock, this natural product replenishes the nutrients necessary to improve health and production. See
Redmond Natural Minerals.
I use a 2-4# pounds of Azomite in every tree hole at planting. Beyond that, I dust the occasional layer in building a garden compost pile as well as "fork in" a full bag across orchard compost piles in late summer. I've also treated underperforming trees with 10-15# of Azomite to up the ante of trace minerals. Seems like the Redmond product could be used in much the same way ... noting that one might want to tone down rates to account for the salt nature of this deposit.
Lost Nation OrchardZone 4b in New Hampshire