Which is the desired result? That people walk the farm; that visitors get to know it; that visitors enjoy learning about farm life and activities?
According to the answer the problem to be solved might change.

For sight disable

Save an area and build an experience based on sounds, smells and texture as the main sources of information.
A place where people can walk with no risk, but experience some kind of challenge. Where people have to find different animals, recognize sounds, enjoy silence, touch nature, plant seeds, embrace trees, differentiate different crops, touch water, know and classify farm tools, touch animals, recognize them by their odor, tell stories about the animals that live in the farm and let people imagine their characteristic and habits; describe a place and let them find it.
May be part of the tour can be guided by another sight disable.