Scientists have developed a breakthrough “superfood” for honeybees by engineering yeast to produce the essential nutrients normally found in pollen. In controlled trials, colonies fed this specially designed diet produced up to 15 times more young, showing a dramatic boost in reproduction and overall health. As climate change and modern agriculture reduce the availability of natural pollen, this innovation could offer a practical way to support struggling bee populations.
Do farmers still do crop rotation? Here in the Netherlands they pump the ground full of the appropriate chemicals so they can grow the same crop in the same place every year.
As for your plan, the fact that bees are getting essential nutrients from those flowers proves a fallow field with wildflowers isn’t being fallow; it’s extracting resources from the soil which may have needed replenishment for crop rotation to work. You can sacrifice productivity for wildflowers, but at that point you’re just designating a space to be a meadow.
The solution is complicated and requires society to step away from the industrial model of agriculture entirely. Food forests are diverse and resilient permaculture, where a farmer does the labor of monitoring nutrient flows through the ecosystem so that a large population of humans can be part of that balanced ecosystem (possibly at a distance, with food being exported and feces imported). Bees are a natural part of such an ecosystem.