Whether we're talking about multi-continental with the bronze age collapse, or we're talking corporate with the US Dust Bowl, people always ask - why didnt anybody do something?
You're assuming people knew there was something to do. You're assuming the people with those means were not instead racing to extract the most profit, just like an oil company.
One local-scale solution is really quite simple, but doesn't lend itself to industrialized single-crop agriculture. Look for "permaculture food forests" in you favorite search engine. Maybe see the results on youtube.
By planting pines with deep taproots, and cutting them off at 6' tall once a year and leaving the yearly growth to rot, you feed the topsoil from above. With the nitrogen-and-phosphorous fixing symbiosis at those same pines' roots, you feed the topsoil from below.
This process takes decades, instead of centuries, because it is deliberate. You can get a head start - now - for you and yours.