I would assume a shock to the system as happened until the farmers adapt to something different.

To call it more primitive doesn't seem honest. Modern farming practices destroy the soil quality while using shortcuts to get higher yield in spite of that. From what I've read I think the jury is still out on which is better. Obviously organic farming is bad for the fertilizer and pesticide business.

I use "more primitive" based on the assumption that less focused development has gone into the technology for organic farming than chemical farming but if the word provides a negative connotation then, well, that's not what I mean.

One of the things I wanted to chime in with, somewhere in the discussion, was that this is the sort of policy which pushes people to develop technologies and that perhaps if deployed more slowly it might have driven innovation in organic farming.

Something like a pilot scheme + opt in + subsidies.

Unlike primitive farming, modern farming is aware of the soil. Primitive farming is what works to a minimal extent, but in general isn't very good for soil health. Modern farming looks to science to figure out what really make soil healthy.