These days, I'm a small-scale inside grower, so what you're wanting to do is beyond my recent experience. I have grown vegetable gardens, though. So, I think it would be helpful to know how you plan to prepare the soil. Do you plan to till it? Would you dig holes and add a soil mix? If it were me, I think I would prepare the soil as I would for a garden plot. Native soil tends to be tightly packed with extensive root structures from grasses and other plants. It also tends to be a home for burrowing rodents. For large scale growing like you're planning, I'd probably till the soil this fall so organics can compost during the off season and pests would look for better places to live. I did grow outside years ago, and remember fighting off slugs, deer and rippers, so some thought should go into how to defend against them.
I wonder about adding potash (which is water-soluble potassium) because the
Gaia Green nutrients include potassium. I've found that
Gaia Green has effective ratios of macronutrients. I don't see a need to change that. Nutrient toxicity can be a problem.
I am not familiar with
superthrive. I have thought about whether adding a product like
Mykos or
Great White would be helpful for plants grown in natural soil. An inoculant might be helpful to reduce the effect of harmful microorganisms, but that's only a guess. These products also have specific beneficial microorganisms that probably would be helpful.
