Agriculture itself has been industrialized for a century in the developed world. It's increasingly industrialized all over the world. Only a small part of the world's cultivated land is worked with techniques recognizable to the farmer of 1850.

If agricultural productivity declined to pre-industrial rates, many people would starve to death. The good news is that population growth is slowing and will probably reverse in the present century. It's still going to be a while yet before widespread de-intensification can be embraced without widespread starvation.

In the mean time, microbial production looks like a good option to provide food for growing populations while limiting environmental damage. It can produce food with lower demands on land, water, and artificially fixed nitrogen than ordinary agriculture. It's resilient against extreme weather events and pest outbreaks.