My understanding is that, in general, the Amish (Old Order) are discouraged from reading their Bibles on their own. This is because I think of the belief that to know too much about the Scriptures would be prideful. 'Scripture-smart' it might be called. Now, this might vary in some districts or settlements.
I believe the leaders want the people to depend on the bi-monthly church services for the two sermons that are delivered. I think you have one sermon that is long, like an hour or so, and another like maybe 20 or 30 minutes. I understand they weave Amish 'specific' practices into the sermons.
But, I don't really recall in any of my readings where the Amish are 'encouraged' to study the Bible on their own in their personal time, except for the ministers and Bishops. Maybe in a few settlements they do. I'd be interested in any recommendation of resources stating they are encouraged.