Soil 302: Exhausted

Conventional agricultural soils are exhausted because we don't replace both macro and micro minerals removed by heavy cropping.

Settlers on the prairie would homestead for 7-10 years, exhaust the soil and move on. We avoid the moving on scenario by applying macro minerals N-P-K-Ca. With this regimen the plants look good but the human body and critters we grow for food need  92 minerals.

So what about the other 88 minerals.